Patent Publication Number: US-2023150756-A1

Title: Rapidly Cooling Food and Drinks

Description:
RELATED APPLICATIONS 
     This patent application claims the benefit of priority under 35 USC § 119(e) to U.S. Patent Application Ser. No. 63/280,492, filed on Nov. 17, 2021, the entire contents of which are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to systems and methods for rapidly cooling food and drinks. 
     BACKGROUND 
     Beverage brewing system have been developed that rapidly prepare single servings of hot beverages. Some of these brewing systems rely on single use pods to which water is added before brewing occurs. The pods can be used to prepare hot coffees, teas, and cocoas. 
     Home use ice cream makers can be used to make larger batches (e.g.,  1 . 5  quarts or more) of ice cream for personal consumption. These ice cream maker appliances typically prepare the mixture by employing a hand-crank method or by employing an electric motor that is used, in turn, to assist in churning the ingredients within the appliance. The resulting preparation is often chilled using a pre-cooled vessel that is inserted into the machine. Some electric ice cream machines take 20 to 60 minutes to make a batch of ice cream and require time consuming clean up. 
     SUMMARY 
     This specification describes systems and methods for rapidly cooling food and drinks. Some of these systems and methods can cool food and drinks in a container inserted into a counter-top or installed machine from room temperature to freezing in less than two minutes. For example, the approach described in this specification has successfully demonstrated the ability make soft-serve ice cream from room-temperature pods in approximately 90 seconds. This approach has also been used to chill cocktails and other drinks including to produce frozen drinks. These systems and methods are based on a refrigeration cycle with low startup times and a pod-machine interface that is easy to use and provides extremely efficient heat transfer. 
     Some pods include a body having a sidewall that extends from a first end of the body to a second end of the body to define an interior of the pod. The pod includes ingredients disposed within the interior of the pod for producing a single serving of a cooled food or drink. The pod includes a mixing paddle or impeller disposed within the interior of the pod and rotatable relative to the body along a longitudinal axis of the body, a cross-section of the mixing paddle taken perpendicular to a longitudinal axis of the mixing paddle having at least one curved or non-linear section. 
     Some pods include one or more of the following features, and/or one or more of the features described elsewhere in this disclosure. 
     In some cases, the at least one curved or non-linear section defines a C-shape, an S-shape, a wavy-shape, an undulating-shape, or a non-linear shape. 
     In some cases, the at least one curved or non-linear section defines a scoop-shaped section for scooping the ingredients within the pod when the mixing paddle rotates relative to the body of the pod. 
     In some cases, the cross-section has a pair of concave features each spaced approximately equidistant from the longitudinal axis of the mixing paddle, the concave features being concave with respect to a rotational direction of the mixing paddle used to mix the ingredients disposed within the interior of the pod to produce the single serving of the cooled food or drink. 
     In some cases, the concave features span a majority of the cross-section of the mixing paddle. In some cases, the cross-section has two radial end portions that are curved in an opposite direction relative to the concave features. In some cases, the two radial end portions contact the sidewall of the body of the pod at one or more rotational positions of the mixing paddle within the pod. In some cases, the two radial end portions maintain contact with the sidewall of the body of the pod during a complete revolution of the mixing paddle about the longitudinal axis of the mixing paddle. In some cases, at least a portion of each of the two radial end portions is tangent to the inner surface of the sidewall of the pod at the one or more rotational positions of the mixing paddle within the pod. 
     In some cases, a radius of the concave features is between 0.6 and 1.2 inches. In some cases, a radius-to-thickness ratio defined by a radius of the concave features of the mixing paddle divided by a thickness the cross-section of the mixing paddle is between 1.0 and 10.0. In some cases, the radius-to-thickness ratio is between 3.0 and 6.0. In some cases, a thickness of the cross-section of the mixing paddle is between 0.10 and 0.30 inches. 
     In some cases, the at least one curved or non-linear section provides an increased bending, flexural, or torsional stiffness to the mixing paddle to resist deflection of the mixing paddle as the mixing paddle rotates within the pod. 
     In some cases, the mixing paddle is concentrically disposed within the interior of the pod such that the longitudinal axis of the body of the pod is coincident with the longitudinal axis of the mixing paddle. 
     In some cases, the mixing paddle has one or more windows passing through it. 
     In some cases, the mixing paddle is longitudinally helical along a longitudinal axis of the mixing paddle. In some cases, the helical mixing paddle has a constant helical pitch between 40 and 60 degrees/inch. In some cases, the helical mixing paddle has a constant helical pitch of 52 degrees/inch. 
     In some cases, the sidewall of the pod and the mixing paddle are formed of a metallic alloy. 
     In some cases, the mixing paddle is coated. In some cases, the coated mixing paddle is electrostatically coated. 
     In some cases, the sidewall of the pod is coated with a layer of coating and the mixing paddle contacts the layer of coating for one or more rotational positions of the mixing paddle within the pod. In some cases, the layer of coating is a layer of PET laminated coating. 
     Some devices located in a hermetically-sealed pod containing liquid food or drink ingredients include a body having a longitudinal mixing paddle. The body has a cross-section along a direction perpendicular to the longitudinal axis of the body. At least a portion of the cross-section is S-shaped. The body has at least two windows passing through the cross-section of the body. The body being sized and shaped such that, when the device is rotated within the pod while the pod is cooled: (i) edges of the device scrape an inner surface of the pod to remove built-up frozen ingredients located on the inner surface of the pod, (ii) the S-shaped portion of the body forces ingredients in an axial direction in the pod and through the at least two windows, and (iii) the device forces frozen confection out of the pod after the pod is opened. 
     Some devices include one or more of the following features, and/or one or more of the features described elsewhere in this disclosure. 
     In some cases, the mixing paddle has a helical-shape. 
     In some cases, the helical shape has a constant pitch between 40 and 60 degrees/inch. In some cases, the constant pitch is 52 degrees/inch. 
     In some cases, edges are in contact with a sidewall of the pod for a majority of angular orientations of the device within the pod. 
     In some cases, the at least two windows are positioned radially along the S-shaped section of the body. 
     In some cases, the cross-section has a pair of concave features each spaced approximately equidistant from a longitudinal axis of the body, the concave features being concave with respect to the direction in which the device is rotated within the pod while the pod is cooled. 
     In some cases, the S-shaped cross-section spans a majority of the cross-section of the body. 
     In some cases, the edges of the device are two helically-extending edges located at opposite radial ends of the cross-section. 
     In some cases, the cross-section provides an increased bending, flexural, or torsional stiffness to the body to resist deflection of the body as the body rotates within the pod. 
     Some systems include a pod and a machine. The pod includes a body having a sidewall that extends from a first end of the body to a second end of the body, the body having an interior that contains ingredients for producing a single serving of a cooled food or drink. A mixing paddle is disposed within the body and rotatable relative to the body along a longitudinal axis of the body, a cross-section of the mixing paddle taken perpendicular to a longitudinal axis of the mixing paddle having at least one curved or non-linear section. The machine has a recess sized to receive the pod. The machine includes a refrigeration system operable to cool the ingredients within the pod when the pod is inserted into the recess of the machine. The machine includes a mixing motor operable to rotate the mixing paddle to mix the ingredients within the pod while the ingredients are being cooled to produce the single serving of the cooled food or drink. 
     Some systems include one or more of the following features, and/or one or more of the features described elsewhere in this disclosure. 
     In some cases, the machine includes an evaporator that defines the recess. 
     In some cases, the at least one curved or non-linear section defines a C-shape or an S-shape. 
     In some cases, the mixing paddle cross-section defines a wavy, undulating shape, or non-linear shape. 
     In some cases, the mixing paddle cross-section has a pair of concave features each spaced approximately equidistant from the longitudinal axis of the mixing paddle, the concave features being concave with respect to the direction in which the mixing motor rotates the mixing paddle to mix the ingredients within the interior of the pod to produce the single serving of the cooled food or drink. 
     In some cases, the mixing paddle cross-section has two radial end portions that are curved in an opposite direction relative to the concave features. 
     In some cases, the machine is operable to rotate the mixing paddle such that edges of the mixing paddle scrape an inner surface of the pod to remove built-up frozen ingredients located on the inner surface of the pod. 
     In some cases, the machine is operable to rotate the mixing paddle to force the ingredients in an axial direction of the pod and through at least two windows of the mixing paddle. 
     In some cases, the machine is operable to rotate the mixing paddle to force the produced single serving of the cooled food or drink out of the pod after the pod is opened. 
     In some cases, the at least one curved or non-linear section provides an increased bending, flexural, or torsional stiffness to the body to resist deflection of the mixing paddle as the mixing paddle rotates within the pod. 
     In some cases, the sidewall of the pod is coated with a layer of coating and the mixing paddle contacts the layer of coating as the mixing paddle is rotated within the pod. In some cases, the layer of coating is a layer of a PET laminated coating. In some cases, the layer of coating has a thickness that remains substantially constant as the single serving of the cooled food or drink is produced. 
     Some methods for producing a single serving of a cooled food or drink include disposing a pod within a recess of a machine, the pod containing ingredients for producing the single serving of the cooled food or drink. The method includes rotating a helical mixing paddle within the pod about a longitudinal axis of a pod such that: (i) edges of the mixing paddle scrape an inner surface of the pod to remove built-up frozen ingredients located on the inner surface of the pod; (ii) the helical shape forces the ingredients within the pod in an axial direction and through at least two windows that extend through a cross-section of the mixing paddle; and (iii) the helical shape forces frozen confection out of the pod after the pod is opened. The mixing paddle has a cross-section along a direction perpendicular to the longitudinal axis of the body, and at least a portion of the cross-section is S-shaped. 
     Some methods include one or more of the following features, and/or one or more of the features described elsewhere in this disclosure. 
     In some cases, the method includes maintaining contact between the edges of the mixing paddle and the inner surface of the pod while the mixing paddle is being rotated to mix the ingredients. In some cases, the method includes cooling a sidewall of the pod to cool the ingredients within the pod to produce the single serving of the cooled food or drink while the mixing paddle is being rotated to mix the ingredients. In some cases, the method includes cooling the mixing paddle via the maintained contact between the mixing paddle and the sidewall of the pod. In some cases, the method includes using the cooled mixing paddle to cool the ingredients. 
     Some pods for a single serving of a cooled food or drink include a body having a sidewall and a base attached to the sidewall, the base and the sidewall together defining an interior of the pod. The pods include a cap attached to the body, the cap extending over at least part of the base and rotatable relative to the base, the cap having a plurality of axially extending protrusions defining a plurality of recesses of the cap that are disposed circumferentially around the cap, the plurality of axially extending protrusions having a thickness that varies along an axial direction. 
     Some pods include one or more of the following features, and/or one or more of the features described elsewhere in this disclosure. 
     In some cases, the plurality of axially extending protrusions have a height that varies along a circumferential direction, the height being along an axial direction. In some cases, the height of the plurality of axially extending protrusions varies along a radial direction. In some cases, the height of the plurality of axially extending protrusions varies along the circumferential direction due to one or more radiussed or bevelled surfaces of the axially extending protrusions. 
     In some cases, the plurality of axial extending protrusions are characterized by radiussed or bevelled sidewalls when projected in a radial direction. 
     In some cases, thickness of the tops of the axially extending protrusions is less than spacing between the respective tops of the axially extending protrusions. In some cases, each axially extending protrusions has substantially the same profile when projected in a radial direction. In some cases, the spacing between the each respective axially extending protrusions is substantially the same. 
     In some cases, an axially-projected surface area of the plurality of recesses of the cap is greater than an axially-projected surface area of the plurality of axially extending protrusions. 
     In some cases, the plurality of axially extending protrusions have curved surfaces that face into the plurality of recesses of the cap. 
     In some cases, the plurality of recesses of the cap are substantially the same shape and size. 
     In some cases, the cap has an opening that extends axially through the cap. In some cases, the opening is located centrally on the cap and located radially inward of the plurality of axially extending protrusions. 
     In some case, the cap includes an insert attached to the cap. In some cases, the insert is formed of metal and the cap is formed of plastic. In some cases, the insert includes a surface configured to engage a protrusion of the base of the pod to open the pod. 
     In some cases, the pod contains ingredients for producing the single serving of the cooled food or drink. 
     Some systems for producing a single serving of a cooled food or drink include a pod and a machine. The pod includes a body having a sidewall and a base attached to the sidewall, the base and the sidewall together defining an interior of the pod, the interior of the pod containing ingredients for producing the single serving of the cooled food or drink. The pod includes a cap attached to the body, the cap extending over at least part of the base and rotatable relative to the base, the cap having a plurality of axially extending protrusions defining a plurality of recesses of the cap that are disposed circumferentially around the cap, the plurality of axially extending protrusions having a thickness that varies along an axial direction. The machine has a recess sized to receive the pod. The machine includes an annular member rotatable relative to a longitudinal axis of the pod when the pod is received in the recess of the machine, the annular member comprising a plurality of radially-extending pins configured to be inserted into at least a subset of the plurality of recesses of the cap when the pod is received in the recess of the machine. The machine includes a refrigeration system operable to cool the ingredients within the pod when the pod is received in the recess of the machine. 
     Some systems include one or more of the following features, and/or one or more of the features described elsewhere in this disclosure. 
     In some cases, receiving the plurality of radially-extending pins into at least the subset of the plurality of recesses of the cap rotationally couples the cap to the annular member. 
     In some cases, each radially-extending pin extends in a radially inward direction from an inner cylindrical surface of the annular member. 
     In some cases, each radially-extending pin has at least one angled surface. In some cases, each angled surface contacts at least a subset of the plurality of axially extending protrusions to cause the cap to rotate relative to the annular member when the pod received in the recess of the machine. 
     In some cases, each radially-extending pin has at least one curved surface. 
     In some cases, the plurality of radially-extending pins are cylindrical pins. In some cases, each cylindrical pin is rotatable along a respective longitudinal axis of the cylindrical pin. 
     In some cases, the plurality of radially-extending pins are four radially-extending pins that are substantially equally spaced around the circumference of the annular member. 
     In some cases, the machine includes a motor rotationally coupled to the annular member, and the motor is operable to rotate the annular member. In some cases, the motor is operable to rotate the annular member to assist in receiving the plurality of radially-extending pins within at least the subset of the plurality of recesses of the cap. 
     Some methods for producing a single serving of a cooled food or drink include inserting a pod into a recess of a machine, the pod containing ingredients for producing the single serving of the cooled food or drink and comprising a cap attached to a base of the pod and rotatable relative to the base of the pod, the cap having a plurality of axially-extending protrusions that define a plurality of recesses. The machine includes an annular member with a plurality of radially-extending pins. Inserting the pod into the recess of the machine causes the plurality of radially-extending pins of the annular member to contact at least a subset of the plurality of recesses in the cap to seat the pod into the machine and rotationally couple the cap to the annular member. 
     Some methods include one or more of the following features, and/or one or more of the features described elsewhere in this disclosure. 
     In some cases, inserting the pod into the recess of the machine causes the plurality of radially-extending pins of the annular member to contact at least a sub-set of the plurality of recesses in the cap to seat the pod into the machine and rotationally couple the cap to the annular member without the need for additional user intervention (e.g., a user does not need to handle or manipulate the pod after insertion). 
     In some cases, the method includes contacting the plurality of radially-extending pins of the annular member with at least a subset of top surfaces of the plurality of axially-extending protrusions of the cap. In some cases, after contacting the plurality of radially-extending pins with at least the subset of the tops of the plurality of axially-extending protrusions, the method includes rotating the cap relative to the annular member (or rotating the annular member relative to the cap. In some cases, after rotating the cap relative to the annular member, the method includes axially moving the pod towards the plurality of radially-extending pins. For example, the pod essentially moves itself downward due to the force of gravity. In some cases, the pod is seated into the machine after the cap is rotated relative to the annular member. In some cases, after contacting the plurality of radially-extending pins with at least the subset of the tops of the plurality of axially-extending protrusions, the weight of the ingredients in the pod and the at least one angled or one curved surface of the radially-extending pins facilitates a downward axially motion of the pod and causes the radially-extending pins of the annular member to contact bottom surfaces of the subset of the plurality of recesses of the cap without the need for additional user intervention. 
     In some cases, inserting the pod into the recess of the machine causes the plurality of radially-extending pins of the annular member to contact bottom surfaces of the subset of the plurality of recesses of the cap. 
     In some cases, the method includes cooling the ingredients within the pod using a refrigeration system of the machine when the pod is seated into the recess of the machine. 
     In some cases, the method includes mixing the ingredients within the pod while cooling the ingredients using the refrigeration system to produce the single serving of a cooled food or drink. 
     In some cases, the method includes rotating an insert of the cap relative to the base of the pod to form or expose an opening in the base of the pod. In some cases, rotating the insert of the cap relative to the base of the pod includes moving a dispensing port of the insert circumferentially around the cap. In some cases, the method includes dispensing the produced single serving of the cooled food or drink through the opening of the base of the pod and the dispensing port of the insert of the cap. 
     The systems and methods described in this specification can provide various advantages. 
     The mixing paddles described in this disclosure maintain contact with the interior sidewall of the pod to reduce the preparation time of making the cooled food or drinks. Some mixing paddles have the same metallic material (e.g., aluminum) as the pod to improve heat transfer and allow the mixing paddle to assist in cooling the ingredients in the pod. Maintaining contact between the mixing paddle and the sidewall of the pod improves the conductive heat transfer to the evaporator. 
     The mixing paddles described in this disclosure include a cross section that includes at least one curved or non-linear section. This curved or non-linear section provides additional flexural, bending, and torsional stiffness to the mixing paddle to reduce situations where the mixing paddle flexes while mixing the cooled food or drink. Flexure is generally bad because it can negatively affect the cooling time because the mixing paddle may cease to make contact with the sidewall of the pod and may not effectively scrape frozen ingredients from the sidewall—thereby building up a layer of frozen product on the inside of the pod which impedes heat transfer to the remaining product within the pod. 
     The drive heads described in this disclosure form a reversible seal with the pod to substantially seal the pod while the pod is in storage and to break the seal during mixing to allow ambient air to be sucked into the pod (e.g., by the whipping action of the mixing paddle) to produce overrun and to assist with dispensing. The drive heads also axially move the mixing paddle within the pod to seat the mixing paddle on a rim of the pod so the mixing paddle maintains concentricity with the pod while mixing and dispensing. 
     The self-seating system described in this disclosure enables pods to be correctly and completely seated in the machine with minimal user assistance. The caps are specially designed with a plurality of curved recesses to help rotate the pod into position in the machine. In some cases, all the user has to do is drop the pod into the machine and the self-seating system and the weight of the contents in the pod will automatically reposition the pod within the machine to properly and fully seat the pod. 
     The QR imaging system described in this disclosure provides a fast and accurate reading of QR labels on pods. The machines use information from the QR labels to determine one or more settings for producing the cooled food or drink rather than prompting the user to manually input information about the pod during each use. The QR imaging system reads the label while the sliding lid of the machine is in motion. The QR imaging system improves the user experience and reduces the chance of the product being mixed improperly due to an incorrect entry by the user. 
     The alternate protrusions described in this disclosure (e.g., clinched protrusions, riveted protrusions, peel-back protrusions) allow the lid of the pod to be manufactured without the large amounts of mechanical cold work required to form an integrally formed protrusion that is sheared off to form an opening in the pod. Reducing the amount of cold work experienced by the lid during manufacturing helps to maintain the original (e.g., annealed) mechanical properties of the lid. This is important since in some cases protrusions would fail prematurely due to material strength issues. Since the clinched and riveted protrusions are formed separately from the lid, they can be manufactured to be thicker than the lid to increase reliability of the protrusion shearing process. They can also be formed of different shapes more easily to increase the contact area with the cap and the reliability of the protrusion shearing process. They also allow the protrusions to be mechanically secured to the lid, obviating the need for glue. 
     The domed shearing lid and cap design described in this disclosure helps to reduce premature failure of the protrusion. For example, the lids on some pods naturally bow when an inert gas (e.g., liquid nitrogen) is introduced into the pod and then the pod is seamed (e.g., the lid of the pod is seamed to the body of the pod). Trying to attach a planar cap on a domed lid can cause the protrusion to jam onto the cap causing premature failure of the protrusion or causing difficulty in getting the protrusion to seat in its proper starting position on the ramp for a reliable shearing process. The domed cap improves this assembly process because the domed cap is contoured to the shape of the domed lid and does not force the protrusion or lid into its planar shape when the cap is attached to the pod. Specifically designing the cap to include a pre-determined bow can help to increase reliability of the protrusion shearing process and reduce the chances that an end user would experience an issue with the machine malfunctioning. The domed cap also provides an initial force on the protrusion when the internal pod pressure is released, requiring less of a “lift” by the ramp. 
     The food science that goes into the ingredients of the pod and the sterilization process that the pod undergoes allows the pods to be shelf-stable for months without requiring refrigeration while providing a consistent and delicious product when consumed. The frozen confections are produced with ice crystals having a size less than 50 microns which is associated with the smoothest ice creams in the world. Example shelf-stable pods include ice cream (dairy and non-dairy and alcohol-infused), frozen yogurt, frozen smoothies, frozen sorbets, frozen protein shakes (e.g., with whey), frozen coffee, and frozen cocktails (e.g., with alcohol). Each of these are also provided in various flavors. The machines described in this disclosure produce all of these products from a shelf-stable pod to a bowl or cone in less than a few minutes. 
     For ease of description, terms such as “upward”, “downward” “left” and “right” are relative to the orientation of system components in the figures rather than implying an absolute direction. For example, movement of a driveshaft described as vertically upwards or downwards relative to the orientation of the illustrated system. However, the translational motion of such a driveshaft depends on the orientation of the system and is not necessarily vertical. 
     The details of one or more embodiments of these systems and methods are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of these systems and methods will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF FIGURES 
         FIGS.  1 A and  1 B  are views of a machine for rapidly producing a chilled or frozen food or drink. 
         FIG.  2    is a cross section view of a pod for use in the machine. 
         FIG.  3    is a schematic showing the flow of ingredients within the pod during a mixing cycle. 
         FIG.  4    is a view of the machine with a top cover removed. 
         FIGS.  5 A and  5 B  are views of the machine with a top cover of the sliding lid assembly removed. 
         FIGS.  6 A and  6 B  are views of a dagger assembly of the machine with the drive shaft in a retracted position. 
         FIGS.  7 A and  7 B  are views of the dagger assembly of the machine with the drive shaft in an engaged position. 
         FIG.  8    is a cross-sectional view of a QR-scanning system of the machine. 
         FIGS.  9 A and  9 B  are perspective views of a pod with a QR barcode for use with the QR-scanning system. 
         FIGS.  10 A and  10 B  is a perspective view of a machine for rapidly producing a chilled or frozen food or drink showing an evaporator mounted in the machine. 
         FIG.  11    is a perspective view of an evaporator of the machine. 
         FIG.  12    is a perspective view of an evaporator with a piano hinge. 
         FIG.  13    is a perspective view of an evaporator with a resilient hinge. 
         FIGS.  14 A and  14 B  are perspective and cross-sectional views of a collet evaporator. 
         FIGS.  14 C and  14 D  are perspective and cross-sectional views of a drill chuck. 
         FIG.  15    is a schematics of a refrigeration system of the machine. 
         FIG.  16    is a plot of a freezing cycle for producing the cooled food or drink with the machine. 
         FIG.  17    is a schematic of a refrigeration system with a refrigerant tank. 
         FIG.  18    is a view of a first end of a pod with its cap spaced apart from its base for ease of viewing. 
         FIG.  19    is a plan view of various embossments for the base of the pod. 
         FIGS.  20 A- 20 G  illustrate rotation of the cap around the first end of the pod to remove a protrusion to open an aperture extending through the base. 
         FIGS.  21 A- 21 C  are views of a base of the pod with a protrusion. 
         FIGS.  22 A- 22 D  are perspective views of a base of the pod having a clinched protrusion. 
         FIGS.  23 A- 23 C  are schematics of tools for forming a clinched protrusion. [ 0108 ]  FIGS.  24 A and  24 B  are cross-sectional views of a base of the pod with a rivet protrusion. 
         FIG.  25    is a perspective view of a base of a pod with a protrusion shaped as a ski-type feature. 
         FIGS.  26 A- 26 D  are views of a domed lid and mating shear drive assembly. 
         FIGS.  27 A and  27 B  are perspective views of peel back lid for a pod. 
         FIGS.  28 A- 28 C  are a sequence of views illustrating the engagement between the peel back lid and a shearing cap. 
         FIGS.  29 A- 29 D  are schematics of an alternative peel back lid having a raking surface with a cavity. 
         FIGS.  30 A- 30 D  are perspective views of a two-piece shearing cap for a pod. 
         FIGS.  31 A- 31 C  are perspective views of a shearing cap with various size orifices. 
         FIGS.  32 A- 32 E  are perspective views of a three-piece shearing cap for a pod. 
         33 A and  33 B are perspective views of a shearing cap with a rubber seal insert. 
         FIGS.  34 A- 34 C  are views of a two-piece shearing cap with tangs integrally formed with the body of the cap. 
         FIG.  35    is an image of product being dispensed from a machine. 
         FIGS.  36 A and  36 B  are images of a prototype shearing cap. 
         FIGS.  37 A and  37 B  are images of a pod with a prototype shearing cap showing residual product on the cap. 
         FIGS.  38 A and  38 B  are images of a pod with a prototype shearing cap showing less residual product on the cap. 
         FIGS.  39 A- 39 D  are perspective views of an over-molded shearing cap for a pod. 
         FIGS.  40 A- 40 C  are views of a prototype shearing cap. 
         FIGS.  41 A- 41 C  are views of a prototype shearing cap. 
         FIGS.  42 A- 42 E  are perspective views of a shearing cap with a dimple. 
         FIGS.  43 A- 43 D  are views of a cap shearing system of a machine. 
         FIGS.  44 A- 44 E  are views of a cap shearing system of a machine. 
         FIGS.  45 A- 45 C  are views of a pod with a cap for use in a self-seating system of the machine. 
         FIGS.  46 A and  46 B  are views of an annular member of the machine for as a part of the self-seating system of the machine. 
         FIG.  47    is a cross-sectional view of a pod inserted into the self-seating system of the machine. 
         FIGS.  48 A- 48 C  are views of a prototype self-seating pod system for a machine. 
         FIG.  49    are views of an alternate self-seating pod system of a machine. 
         FIGS.  50 A and  50 B  are view of a pod with a prototype cap for the self-seating system. 
         FIGS.  51 A- 51 C  are perspective and cross-sectional views of a mixing paddle with ribbed edges. 
         FIGS.  52 A- 52 C  are perspective and cross-sectional views of a mixing paddle having a cross-section with convex features oriented in the mixing direction. 
         FIGS.  53 A- 53 C  are perspective and cross-sectional views of a mixing paddle having a cross-section with concave features oriented in the mixing direction. 
         FIGS.  53 D and  53 E  are views of curved radial ends of a mixing paddle. 
         FIGS.  54 A and  54 B  are perspective views of a prototype mixing paddle. 
         FIGS.  55 A- 55 C  are views of a mixing paddle with a notch for engaging a lip of a pod. 
         FIGS.  56 A and  56 B  are views of a mixing paddle with a perpendicular shoe. 
         FIGS.  57 A- 57 C  are views of a threaded drive head for a mixing paddle. 
         FIGS.  58 A- 58 D  are views of a threaded drive head for a mixing paddle. 
         FIG.  59    is a perspective view of a foam structure for diffusing gas and liquid spray. 
     
    
    
     Like reference symbols in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     This specification describes systems and methods for rapidly cooling food and drinks. Some of these systems and methods use a counter-top or installed machine to cool food and drinks in a container from room temperature to freezing in less than three minutes. For example, the approach described in this specification has successfully demonstrated the ability make soft-serve ice cream, frozen coffees, frozen smoothies, and frozen cocktails, from room temperature pods in approximately 90 seconds. This approach can also be used to chill cocktails, create frozen smoothies, frozen protein and other functional beverage shakes (e.g., collagen-based, energy, plant-based, non-dairy, and CBD shakes), frozen coffee drinks and chilled coffee drinks with and without nitrogen in them, create hard ice cream, create milk shakes, create frozen yogurt and chilled probiotic drinks. These systems and methods are based on a refrigeration cycle with low startup times and a pod-machine interface that is easy to use and provides extremely efficient heat transfer. Some of the pods described can be sterilized (e.g., using retort sterilization or aseptic filling) and used to store ingredients including, for example, dairy products at room temperature for up to 18 months. 
     These machines, pods, and refrigeration systems are described in detail in U.S. patent application Ser. No. 15/625,690 (attorney docket number 47354-0003001) filed Jun. 16, 2017, U.S. patent application Ser. No. 16/104,758 (attorney docket number 47354-0004001) filed Aug. 17, 2018, U.S. patent application Ser. No. 16/459,388 (attorney docket number 47354-0006001) filed Jul. 1, 2019, U.S. patent application Ser. No. 16/459,176 (attorney docket number 47354-0009001) filed Jul. 1, 2019, U.S. patent application Ser. No. 16/459,322 (attorney docket number 47354-0010001) filed Jul. 1, 2019, U.S. patent application Ser. No. 16/824,616 (attorney docket number 47354-0036001) filed Mar. 19, 2020, U.S. patent application Ser. No. 16/844,781 (attorney docket number 47354-0012001) filed Apr. 9, 2020, and U.S. patent application Ser. No. 17/335,891 (attorney docket number 47354-0037001) filed Jun. 1, 2021, all of which are incorporated herein by reference in their entirety. 
     A significant challenge in the design of ice cream machines is the ability to cool a pod from room temperature to the draw temperature as quickly as possible, preferably within two minutes. Some machines reduce the residence time the ice cream remains in the ice cream machine by reaching the draw temperature as quickly as possible. This can be achieved by mixing and cooling as quickly as possible. 
     The machines and processes described in this specification create ice cream with the majority of the ice crystals below 50 μm and often the majority is below 30 μm in a single serve pod. In order to still be able to dispense the ice cream out of the pod into a bowl or dish without the ice cream contacting the machine, a draw temperature or dispensing temperature of the ice cream should be between −3° to −8° C. (26.6° F. to 17.6° F.) and preferably between −3° to −6° C. (26.6° F. to 21.2° F.). 
       FIGS.  1 A and  1 B  show a machine  100  for producing a chilled or frozen food or drink.  FIG.  1 A  shows the machine  100  in a closed configuration and  FIG.  1 B  shows the machine  100  in an open configuration. A user pushes and pulls a sliding lid  102  (e.g., by grasping a handle  104 ) to move the machine  100  between the closed and open configurations. Some machines have an automated system (e.g., one or more motors or actuators) to open and close the sliding lid  102  without user assistance. 
     The sliding lid assembly  102  reduces the overall height of the machine  100  compared to machines with lid assemblies that open upward (e.g., pivoting designs). In some examples, machine  100  is compact and able to fit on kitchen countertops underneath cupboards. Machine  100  has a height (top to bottom) of about 17.5 inches, a depth (front to back) of about 20 inches, and a width (side to side) of about 12 inches. Some machines have other dimensions. Some machines have a height of less than 20 inches (e.g., between 16 and 20 inches), a depth of less than 24 inches (e.g., between 18 and 24 inches), and a width of less than 16 inches (e.g., between 10 and 16 inches). Some machines are larger to accommodate larger more powerful compressors. 
     In the open configuration shown in  FIG.  1 B , a user (e.g., a consumer) inserts a pod  200  into a receptacle  106  of the machine  100 . The receptacle  106  is defined by one or more surfaces of an evaporator of the machine  100 . An example pod  200  is shown inserted into the receptacle  106  and described with reference to  FIG.  2   . The machine  100  reduces the temperature of ingredients in the pod  200  to produce a single serving of a cooled food or drink. 
       FIG.  2    is a schematic side view of an example pod  200  for use in machine  100 . The pod  200  includes a body  202  that extends from a first end  204  at an open end or base of the pod  200  to a second end  206  at a closed end of the pod  200 . The pod  200  is cylindrical and has a circular cross-section. A sidewall  208  connects the first end  204  to the second end  206 . The first end  204  has a diameter D UE  that is slightly larger than the diameter D LE  of the second end  206 . The sidewall  208  has a circular cross-section with a diameter D B . The diameter D B  is larger than both the diameter DUE of the first end  204  and the diameter D LE  of the second end  206 . This configuration of the pod  200  provides a balance between reducing material usage (e.g., aluminum) while increasing the columnar strength of the pod and facilitates stacking multiple pods  200  on top of one another with the first end  204  of one pod receiving the second end  206  of another pod. 
     The pod  200  includes a mixing paddle  250  disposed within the body  202  of the pod  200 . In some examples, the mixing paddle is referred to as an impeller or a blade. The mixing paddle  250  is rotatable within the pod  200  and is concentrically disposed within the pod  200 . The mixing paddle  250  includes a drive head  252  with a receptacle for engaging a drive shaft of the machine  100  for driving the mixing paddle  250  within the pod  200  to produce the serving of the cooled food and drink. Further details about mixing paddle  250  are described with reference to  FIGS.  52 A- 52 C . 
     Some pods are sized to provide a single serving of the food or drink being produced. Some pods have a volume between 6 and 18 fluid ounces. Pod  200  has a volume of approximately 8.5 fluid ounces. Some pods are filled with all of the ingredients needed to produce the cooled food or drink (except that ambient air is sucked into the pod from the atmosphere while producing the cooled food or drink). Some pods are filled approximately half-way (e.g., between 40% and 60% fill by volume) with the ingredients and the remaining headspace being pressurized with an inert gas (e.g., nitrogen) before the pod is sealed. Some pods are filled ⅓ of the way (e.g., 33% by volume), and some pods are filled ⅔ of the way (e.g., 66% by volume). The remaining head space in the pod allows the ingredients to slosh around during a retort sterilization process which improves heat transfer. The headspace also provides room in the pod for the ingredients to expand (e.g., foam or create overrun) in the pod  200  while the cooled food or drink is produced (e.g., when the mixing paddle  250  whips the ingredients at large RPMs (e.g., over 50 RPM, over 100 RPM, over 200 RPM, etc.) while drawing air into the pod  200  to produce overrun). Some pods do not need to introduce air and can rely on the inert gas (e.g., nitrogen) in the pod. In these cases, the pod can remain sealed during at least part of the mixing process. In some cases, air can be introduced during the mixing process. 
     The thickness and material of the sidewall  208  of the pod  200  enables the pod  200  to provide fast and efficient heat transfer between the evaporator of the machine  100  and the ingredients within the pod  200 . Some pods have a sidewall  208  that is formed of aluminum or an aluminum alloy and is between 5 and 50 microns thick. 
     Some mixing paddles  250  are formed of the same material as the sidewall  208  of the pod  200  to provide even better heat transfer between the evaporator of the machine  100  and the ingredients within the pod  200 . For example, some pods have a sidewall  208  formed of an aluminum alloy, and the mixing paddle  250  is also formed of an aluminum alloy (e.g., the aluminum alloy need not be the exact same). Some evaporators include an aluminum inner surface that defines the receptacle  106  so the material is the same between the evaporator, the pod  200 , and the mixing paddle  250 . Since the materials are the same, or substantially the same, the thermal expansion and thermal conductivity are also the same, or substantially the same. This means that during cooling, the evaporator, the sidewall  208 , and the mixing paddle  250  all conduct heat at the same rate and expand or shrink at the same rate. This allows the engagement and contact pressure between these three components to be the same. This further improves heat transfer and reduces the time required to produce the cooled food or drink. 
     The bodies of some pods and mixing paddles are made of other materials, for example, tin, stainless steel, and various polymers such as polyethylene terephthalate (PET). Some pods are made of different materials to assist with the manufacturability and performance of the pod. For example, the pod walls and the second end  206  may be made of 3000-series Aluminum (e.g., 3104) while the base may be made of 5000-series Aluminum (e.g., 5182). Some pods include different series of Aluminum (e.g., 2000-series, 6000-series, etc.). 
     In some pods, the internal surfaces of the pod are coated with a lacquer to prevent corrosion of the pod as it comes into contact with the ingredients contained within pod. This lacquer also reduces the likelihood of “off notes” of the metal in the food and beverage ingredients contained within pod. For example, a pod made of aluminum may be internally coated with one or a combination of the following coatings: Sherwin Williams/Valspar V70Q11, V70Q05, 32SO2AD, 40Q60AJ; PPG Innovel 2012-823, 2012-820C; and/or Akzo Nobel Aqualure G1 50. Other coatings made by the same or other coating manufacturers may also be used. Some pods are internally coated with a layer of coating and the mixing paddle is sized to contact the layer of coating as the mixing paddle is rotated within the pod. In some examples, the layer of coating is a layer of a PET laminated coating. In some examples, the layer of coating has a thickness that remains substantially constant as the single serving of the cooled food or drink is produced (e.g., the coating does not rub off). 
     Some mixing paddles are made of the same or similar aluminum alloys and coated with similar lacquers/coatings. For example, Whitford/PPG coating 8870 may be used as a coating for mixing paddles. The mixing paddle lacquer may have additional non-stick and hardening benefits for the mixing paddle. Some mixing paddles are electrostatically coated. Some mixing paddles are made of AL 5182-H48 or other aluminum alloys. Some mixing paddles exhibit a tensile strength of 250-310 MPa minimum, a yield strength of 180-260 MPa minimum, and an elongation at break of 4%-12%. 
     Some mixing paddles are reusable by removing them from the pod, washing them, and reusing them in the same or another pod. In some cases, the pod and the mixing paddle are both formed of aluminum and are both recyclable without having to take apart the pod and separate the mixing paddle from the pod (e.g., removal of the mixing paddle from the pod is generally difficult for a consumer to do and not necessary). 
       FIG.  3    is a schematic  270  of the flow of ingredients during mixing. In this illustration, the pod and the mixing paddle are frustoconical in shape but this flow of ingredients is also present for the cylindrical pods such as pod  200  and mixing paddle  250 . As the mixing paddle rotates within the pod, the helical shape of the mixing paddle draws the ingredients from the sidewall of the pod to the center of the pod and upward in an axial direction (e.g., as denoted by arrows  272 ). The ingredients also pass through one or more openings of the mixing paddle. The ingredients make significant contact with the mixing paddle during the mixing process and having a cooled mixing paddle allows the mixing paddle to aid in the freezing process. This is an advantage in cases where the mixing paddle is metal (e.g., aluminum) or otherwise has a large thermal conductivity. 
     Edges of the mixing paddle  250  continuously contact and scrape the sidewall  208  of the pod  200  to remove ice and frozen ingredients off of the sidewall  208 . The mixing paddle  250  moves the scraped ingredients to the center of the pod  200  so the cooler ingredients at the sidewall are mixed with the ingredients in the warmer center to improve heat transfer and cool faster. The mixing paddle  250  maintains contact against the sidewall  208  for all rotational positions of the mixing paddle  250  (e.g., as the mixing paddle  250  revolves about 360 degrees within the pod  200 ). Pods with a sidewall that is the same material as the mixing paddle makes this process more efficient since the thermal expansion and thermal conductivity are the same. Some machines oscillate and/or vibrate the mixing paddles to help remove product sticking to the mixing paddle and/or sticking to the sidewall of the pod. 
     Some pods are formed from commercially available can sizes, for example, “slim” cans with diameters ranging from 2.080 inches-2.090 inches and volumes of 180 milliliters (ml)-300 ml, “sleek” cans with diameters ranging from 2.250 inches-2.400 inches and volumes of 180 ml-400 ml and “standard” size cans with diameters ranging from 2.500 inches-2.600 inches and volumes of 200 ml-500 ml. The machine  100  is configured to use pods with 2.085±0.10 inches outer diameter. Some pods have an inner diameter of 2.065 inches to 2.075 inches to allow mixing paddles with a diameter of 2.045 to 2.055 inches, respectively, to rotate at an RPM of 100 to 1,500 RPM, resulting in 6,000 to 93,000 square inches scraped per minute. 
     With an inner diameter of about 2.085 inches, the pod can accommodate a mixing paddle with a diameter of about 2.065 inches to 2.085 inches (i.e., some mixing paddles have the same diameter as the pod). The mixing paddle can revolve in the pod at rotational speeds ranging between 100 RPM and 1,500 RPM. During this time the blade edges of the mixing paddle scrape the internal walls of the pod at rates ranging from 3,100 to 46,500 square inches per minute. The scraped area per minute multiplies with each scraping edge on the mixing paddle (i.e., a mixing paddle with two edges would scrape approximately 6,200 to 93,000 square inches per minute). This scraping and mixing process helps distribute the ice crystals that form at the wall of the pod to the interior of the pod. 
     Some pods have a decorative external coating of no more than 10-50 microns thickness (e.g., less than 50 microns). Some pods do not have an internal or external coating on the ends. 
     In addition to single-use pods, some pods are reusable. Some pods are used, washed, and reused. Some pods are purchased empty and filled before use. Some pods are purchased or acquired full, used, and refilled by a user or by the machine. Some pods are sterilized after use and sterilized after refill to enable room temperature storage (e.g., shelf-stable pods). Some pods include resealed features that allow the pod to be refilled and resealed. Some pods can be purchased empty and used with a home ice cream making kit with clean-label ingredients. 
     Additional examples of mixing paddles are described with reference to  FIGS.  48 A- 53 B . Other mixing paddles and pods that can be used with machine  100  are described in more detail in U.S. patent application Ser. No. 16/459,322 (attorney docket number 47354-0010001) filed Jul. 1, 2019, and U.S. patent application Ser. No. 16/824,616 (attorney docket number 47354-0036001) filed Mar. 19, 2020, both of which are incorporated herein by reference in their entirety. 
     The machine  100  includes a touch-screen user interface  108 . A user engages with the user interface  108  to select/confirm one or more settings of the machine  111  (e.g., select the product to be produced, confirm the product, etc.), display an indication of time remaining during the process of producing the cooled food or drink (e.g., a circular display, a bar display, a digital clock, etc.), and display instructions for the user (e.g., ask the user to place their bowl or cone in the dispensing area  110  of the machine  100  to get ready for the product to be dispensed). 
       FIG.  4    is a perspective view of the machine  100  with the top cover of the machine  100  removed. The sliding lid  102  is mounted on a pair of cylindrical rails  112  and is linearly slidable back and forth to open and close the area where the pod  200  is inserted. 
       FIGS.  5 A and  5 B  are perspective views of the machine  100  with the top cover of the machine  100  removed and the top cover of the sliding lid  102  removed.  FIG.  5 A  shows the machine  100  in the closed configuration and  FIG.  5 B  shows the machine in the open configuration. The sliding lid  102  includes a housing  114  that includes a drive motor  116  mounted on an underside of the housing  114 . The drive motor  116  includes a motor shaft  118  that is rotationally coupled to the mixing paddle  250 . The rotational coupling involves transferring torque from the drive motor  116 , through a belt  120 , to an axially movable drive shaft  122  (shown in  FIGS.  6 A and  6 B ). 
     In some machines, the motor provides at least 50 ozf-in (ounce-force inch) of torque at a rotational velocity of at least 100 RPM (rotations per minute) at the mixing paddle. For example, a torque of 100 ozf-in and a rotational speed of 750 RPM may be used. In some machines, the drive motor  116  provides a torque of up to 400 ozf-in and a rotational speed of up to 1,500 RPM. Some machines increase the mixing speed of the mixing paddle  250  to help mix air (or the inert gas in the pod) into the frozen confection to achieve improved overrun (preferably at least 30% overrun). Some machines increase the mixing speed of the mixing paddle  250  to provide enough velocity to extrude the ice cream out of the exit port of the pod  200  while achieving a constant flow (stream) of ice cream coming out of the pod. 
     Increasing the rotational velocity of the mixing paddle  250  increases the required electric current. The table below illustrates electrical currents of the current prototype machine that are used to drive the mixing paddle  250  as a function of RPM and time into the freezing process (which affects the viscosity of the ice cream). 
     
       
         
           
               
               
            
               
                   
                   
               
               
                   
                 Seconds from start of the freezing cycle 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                 3 
                 15 
                 30 
                 45 
                 60 
                 75 
                 90 
                 105 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 RPM of the mixing paddle 
                 275 
                 275 
                 275 
                 315 
                 435 
                 558 
                 800 
                 1000 
               
               
                 Current on the motor that 
                 372 
                 658 
                 1202 
                 1833 
                 2738 
                 4491 
                 9192 
                 13719 
               
               
                 drive the mixing paddle 
               
               
                 (milliamps) 
               
               
                   
               
            
           
         
       
     
     The machine  100  raises and lowers the drive shaft  122  via a plunger motor  124  (shown in  FIG.  6 B ) to axially and rotationally engage the drive shaft  122  to the receptacle of the drive head  252  of the mixing paddle  250 . The drive motor  116  and the plunger motor  124  are mechanically attached to the sliding lid assembly  102  so they both translate with the sliding lid assembly  102 . The belt  120  is under tension both when the lid is in its open position and when the lid is in its closed position. The belt  120  also translates with the sliding lid assembly  102 . Some machines include a belt tensioning system to maintain the tension of the belt  120 . 
       FIGS.  6 A and  6 B  are views of the plunger assembly of the machine  100  in a disengaged configuration with the pod  200 . The plunger motor  124  is axially coupled to the drive shaft  122  via a rack and pinion system  126 . The plunger motor  124  translates the drive shaft  122  axially between the disengaged configuration (shown in  FIGS.  6 A and  6 B ) and an engaged configuration (shown in  FIGS.  7 A and  7 B ). A pulley  127  is rotationally coupled to the belt  120 . The pulley  127  has a keyed bore  128  (e.g., a hexagonal-shaped bore) that slidably receives the similarly keyed drive shaft  122  and rotationally couples the torque of the drive motor  116  to the drive shaft  122 . 
     In some machines, an onboard controller (or processor) monitors the axial position of the drive shaft  122  using an encoder (not shown) on the plunger motor  124  and a limit switch (not shown). For instance, when the user inserts the pod  200  into the machine  100  and presses the start button (e.g., via the user interface  108 ) or when the user inserts the pod  200  into the machine  100  and the QR system of the machine  100  reads the QR code on the pod  200 , the evaporator closes around the pod  200  to clamp the pod  200  into the machine  100  and the drive shaft  122  plunges into the receptacle of the drive head  252  of the pod to rotatably couple the drive shaft  122  to the mixing paddle  250 . Some machines wiggle and/or rotate the drive shaft  122  during the plunging process to ensure proper alignment with the receptacle of the drive head  252  before mixing and freezing would commence. 
       FIG.  8    is a perspective view of a QR scanning system  130  for the machine  100 . The QR scanning system  130  is mechanically mounted to the housing  114  of the sliding lid  102 . The QR scanning system  130  includes a camera scanner  132  that is operable to read a QR code  210  on a label of pod  200 . In some examples, the QR code  210  is printed on a lid  212  or cover of the pod  200 . In some examples, the QR code  210  is printed directly on the metal (e.g., aluminum) at an end of the pod  200 . 
     The QR code  210  contains information to select parameters for preparation of the cooled food or drink. Examples of parameters include evaporator close pressure and sequence, mixing paddle rotation speed, cycle time, evaporant temperature, and cycle and dispense temperatures. Some QR codes  210  include information about the product (e.g., ice cream favor, alcoholic content, etc.). The information density of the QR code may be customized to fit the camera&#39;s detection window. In some cases, the QR code is single input which indicates a predetermined recipe in the built-in memory of the machine  100 . In some cases, the memory of the machine  100  is updated by downloading new recipes and these recipes are compared against the information of the QR code  210  during use of the machine  100 . 
     The QR scanner  132  moves with the opening and closing of the sliding lid  102 . As the sliding lid  102  is pulled forward (e.g., to the closed position) after the user has inserted the pod  200 , the scanner  132  reads the information on QR code  210  on top of the pod. The QR scanner  132  images the QR code  210  before the sliding lid  102  is moved to the closed configuration. This is because, when the machine  100  is in the closed configuration, the QR scanner  132  would have already passed by the pod  200  since the drive shaft  122  would be moved to a position where it is collinear with the longitudinal axis of the mixing paddle  250 . The QR scanner  132  is designed to image the QR code  210  quickly and accurately during this short time window and while the sliding lid  102  is in motion. 
     In some cases, if no QR code is detected, the user is prompted to open and close the lid  102  again. The user may also bypass the QR code by manually entering the pod type through the user interface  108 . The scanner  132  is oriented at a 15 degree angle relative to the horizontal plane of the foil label and QR code  210 . Some scanners are oriented at a 12 degree angle to 17 degree angle. The scanner  132  has a resolution of 1280×800 pixels, a focal distance of 18 cm (7.0 in), a horizontal field of view of 48 degrees and a vertical field of view of 30 degrees. Some scanners may have a focal distance of 16 cm to 20 cm. The scanner  132  must be able to read the QR code  210  of the pod  200  while the scanner  132  is in motion as it slides between the opened and closed configuration. The scanner  132  needs the QR code  210  at an appropriate focal length and angle to be read. 
       FIGS.  9 A and  9 B  are perspective views of a pod with a dome foil  214 . Dome foil  214  is made of an appropriate material to maintain the optimal balance of adhesion to the pod, strength and rigidity and limited reflectivity. The dome foil  214  includes one or more codes (e.g., QR codes, barcodes). In the example shown, the foil  214  includes two QR codes  215  offset from the center and diametrically opposite each other. The QR scanning system  130  reads at least one and sometimes both of the QR codes  215  on the dome foil  214 . In some cases, the two QR codes  215  are the same codes to give the QR scanner  132  two opportunities to read information from the pod. In some cases, one of the codes  215  becomes damaged during shipping and handling of the pod while the other code  215  remains intact. In some cases, the codes  215  are different to communicate different information to the machine  100  (e.g., one code is used for half of the settings and the other code is used for the remaining half of the settings). 
     The identification information of the codes can also be used to facilitate direct to consumer marketing (e.g., over the internet or using a subscription model). Some machines use this approach to sell ice cream thru e-commerce because the pods are shelf stable. In such a subscription mode, customers pay a monthly fee for a predetermined number of pods shipped to them each month. The customers select their personalized pods from various categories (e.g., ice cream, healthy smoothies, frozen coffees or frozen cocktails, etc.) as well as their personalized flavors (e.g., chocolate or vanilla). In some cases, the machine itself can be rented using a subscription model. In some cases, reusable pods and mixing paddles can be rented as well. 
     The identification can also be used to track each pod used. In some systems, the machine is linked with a network and can be configured to inform a vendor as to which pods are being used and need to be replaced (e.g., through a weekly shipment). This method is more efficient than having the consumers go to the grocery store and purchase pods. 
       FIGS.  10 A and  10 B  are perspective and cross-section views of a machine  150  for producing a single serving of a cooled food or drink. Machine  150  is similar to machine  100  but includes a pivoting lid  152  instead of the sliding lid  102  of machine  100 . Both machine  100  and  150  include an evaporator  154  for cooling the pod  200  when the pod  200  is inserted into the respective machine. Additional evaporators for use with machines  100  and  150  are described in U.S. patent application Ser. No. 16/459,388 (attorney docket number 47354-0006001) filed Jul. 1, 2019, and U.S. patent application Ser. No. 16/824,616 (attorney docket number 47354-0036001) filed Mar. 19, 2020, both of which are incorporated herein by reference in their entirety. 
       FIG.  11    is a perspective view of the evaporator  154  for cooling a pod. The evaporator  154  has a clamshell configuration with a first portion  156  attached to a second portion  158  by a living hinge  160  on one side and separated by a gap  162  on the other side. Inner surfaces  168  of the evaporator  154  define a receptacle  170  for receiving a pod (e.g., pod  200 ). Refrigerant flows to the evaporator  154  from other components of a refrigeration system of the machine  100  (e.g., a condenser) through fluid channels  164  (shown in  FIG.  10 B ). The refrigerant flows through the evaporator  154  in internal channels through the first portion  156 , the living hinge  160 , and the second portion  158 . In some evaporators, the first portion  156  and the second portion  158  are mechanically separate parts that are joined together by a hinge other than a living hinge  160  (e.g., a piano hinge (see  FIG.  12   ) or a deformable hinge (see  FIG.  13   ). In some evaporators, the first portion and second portion are not hinged at all (e.g., two separate halves are pushed together and pulled apart by one or more motors of the machine). Some evaporators have three or more sections (e.g., between 3-10 sections) that are hinged or forced together by one or more motors of the machine. 
     The evaporator  154  has an open position and a closed position. In the open position, the gap  162  opens to provide an air gap between the first portion  156  and the second portion  158 . The inner diameter ID of the evaporator  154  is larger in the open position than in the closed position. Pods can be inserted into and removed from the evaporator  154  while the evaporator  154  is in its open position. Transitioning the evaporator  154  from its open position to its closed position after a pod is inserted tightens the evaporator  154  around the outer diameter of the pod to clamp the pod in place and limit rotational and axial movement of the pod via friction. For example, the machine  100  is configured to use pods with a 2.085 inches outer diameter. The evaporator  154  has an inner diameter of 2.115 inches in the open position and an inner diameter inner diameter of 2.085″ in the closed position. Some machines have evaporators sized and configured to cool other sized and shaped pods (e.g., frustoconical). 
     The closed position of evaporator  154  improves heat transfer between an inserted pod  200  and the evaporator  154  by increasing the contact area between the pod  200  and the evaporator  154  and reducing or eliminating an air gap between the sidewall  208  of the pod  200  and the inner surface of the evaporator  154 . In some pods, the pressure applied to the pod by the evaporator  154  is opposed by the mixing paddle, pressurized gases within the pod, or both to maintain the casing shape of the pod. This ensures mechanical contact between the evaporator, the sidewall of the pod, and the mixing paddle to improve heat transfer while the evaporator  154  cools the pod and while the mixing paddle mixes the ingredients within the pod. In some examples, the portion of the evaporator in contact with the pod, the sidewall of the pod, and the mixing paddle are formed of the same material so that thermal expansion is the uniform across the evaporator, mixing paddle, and pod during the cooling and mixing process. In some examples, the evaporator, mixing paddle, and pod are all formed of one or more aluminum alloys for this purpose. 
     Machine  150  includes an evaporator motor  166  that is mechanically coupled to the evaporator  154  and rotates a bolt  174  to move the evaporator  154  between its open and closed configuration. Some machines include an evaporator motor that is directly attached to the evaporator  154  and bolt  174 . The evaporator motor  166  controls the closure of the evaporator  154  against the bias of two springs  172  to provide a closure force against the pod  200  of approximately 10-50 lbf (pound-force) and an approximate torque clamping force of 1,000 to 1,500 ozf-in. In some examples, the evaporator motor  166  uses a feedback control system to know when the evaporator has reached the closed configuration. For example, when the voltage and/or current of the evaporator motor  166  reaches a threshold, the evaporator motor  166  determines that evaporator  154  is in the closed configuration and locks the evaporator  154  at the current position to maintain the clamping pressure on the pod  200 . Some machines use a hard-stop system where the evaporator motor  166  stops when the evaporator reaches a particular amount of closure. Instead of an evaporator motor  166 , some machines use “wedge system” such that a manual force applied by the user (e.g., when the sliding lid  102  is closed or when the pivoting lid  152  is closed) forces the evaporator  154  into the closed position (and vice versa). 
       FIG.  12    is a perspective view of an evaporator  311  that includes a piano hinge  301  instead of a living hinge. In some cases, using a piano hinge  301  reduces fatigue failure that can occur in the living hinge due to repeated open and close cycles. In evaporator  311 , each half of the evaporator is fluidly disconnected from each other such that each half of the evaporator has an inlet and an outlet port (not shown in  FIG.  12   ). 
       FIG.  13    is a perspective view of an evaporator  315  that includes a resilient or deformable hinge  303  instead of a living hinge. In some cases, using a deformable hinge  303  allows a highly resilient metal (e.g., spring steel) to be used for the deformable hinge  303  while the remainder of the evaporator is formed of aluminum (e.g., to match the body of the pod and the mixing paddle). It also focuses any failures to the discrete hinges  303  which can be easily replaced without having to discard or rework the entire evaporator (which may be the case if the living hinge failed). Similar to evaporator  311 , in evaporator  315 , each half of the evaporator is fluidly disconnected from each other such that each half of the evaporator has an inlet and an outlet port (not shown in  FIG.  13   ). 
     In some examples, the feedback control system of the evaporator motor  166  is used to calibrate the evaporator closure and ensure that evaporators  154  close to the same fixed inner diameter upon every closure cycle. In one example, the feedback control system is used to determine the fully closed position of the evaporator  154 , i.e., the smallest inner diameter. The evaporator  154  is then moved by the evaporator motor  166  to the fully open position, i.e., the largest inner diameter, and an encoder used to determine the number of counts between the fully closed and fully opened positions of the evaporator  154 , which may correspond to rotations of the bolt  174 . A calibration plug with a predetermined diameter approximating that of a pod (e.g., pod  200 ) is then inserted into the evaporator cavity of the evaporator  154  while the evaporator  154  is in the fully open position, and the feedback control system of the evaporator motor  166  is used again to determine the closed position of the evaporator  154 , this time when closed on the plug (the calibrated close position). 
     The inner diameter of the evaporator  154  in the calibrated close position generally falls between the inner diameter of the evaporator  154  in the fully open position and the inner diameter of the evaporator  154  in the fully closed position. The encoder is used to determine the number of counts between the fully closed position and the calibrated close position. This data serves as a basis for opening and closing the evaporator  154  to fixed (e.g., constant) and repeatable inner diameters when operating the machine. This process is particularly useful for improving machine-to-machine reproducibility with evaporators  154  of slightly varying bore sizes. 
     In some machines, the feedback control system of the evaporator  154  monitors electrical current level of the evaporator motor  166  as the evaporator  154  reaches the closed positon to determine the travel limit of the evaporator  154 . In some examples, an increase in electrical current corresponds to an increase in mechanical force applied to the pod  200 . For example, the machine  100  measures the electrical current drawn by the evaporator motor  166  over time and compares this measured current to a current threshold. If the electrical current threshold is reached, then the machine  100  determines that the evaporator  154  has reached the closed position and controls the evaporator motor  166  to limit (or stop) closing the evaporator  154  to avoid crushing the pod  200  within the evaporator  154 . 
     In some machines, the feedback control system of the evaporator  154  monitors the rotational velocity (RPM) of the evaporator motor  166  as the evaporator  154  reaches the closed positon to determine the travel limit of the evaporator  154 . In some examples, a decrease in rotational velocity corresponds to an increase in mechanical force applied to the pod  200 . For example, the machine  100  measures the rotational velocity at an output shaft of the evaporator motor  166  over time using an encoder and compares this measured rotational velocity to a velocity threshold. If the rotational velocity decreases below a rotational velocity threshold, then the machine  100  determines that the evaporator  154  has reached the closed position and controls the evaporator motor  166  to limit closing the evaporator  154  to avoid crushing the pod  200  within the evaporator  154 . 
     In some examples, it is desirable that the evaporator  154  be shut and holding the pod  200  in a tightly fixed position before the sliding lid  102  closes or pivoting lid  152  closes and the drive shaft lowers to engage the mixing paddle  250  of the pod  200 . This positioning can be important for shaft-mixing paddle engagement. 
       FIGS.  14 A and  14 B  are views of a collet evaporator  300 . In some cases, evaporator  154  encounters fatigue issues at the living hinge  160  and/or simply due to repeatedly opening and closing the evaporator during the life cycle of the machine. Some machines include the collet evaporator  300  instead of evaporator  154  to reduce fatigue issues. In some examples, the collet evaporator  300  functions like a collet device to secure a drill bit to a drill or to an end mill. In some examples, the collet evaporator  300  functions like the drill chuck  313  shown in  FIGS.  14 C and  14 D . 
     Collet evaporator  300  includes three parts—an upper part  302 , a lower part  304 , and a collet  305 . The lower part  304  is formed of metal (e.g., aluminum) and includes a helical recess to receive a helical refrigerant channel  306  (e.g., a copper tube) that spirals around the outer periphery of the lower part  304 . The lower part  304  includes one or more threads  308  for threadably receiving one or more threads of the upper part  302 . The upper part  302  is screwed into the lower part  304 . An end portion of the collet  305  engages an annular ramped surface  307  of the upper part  302  to couple axially movement of the upper part  302  and the collet  305 . The collet  305  includes an expanding/contracting portion  310  formed of metal (e.g., aluminum or stainless steel). The expanding portion  310  is flexible due to axial slits  314  on diametrically opposite sides. 
     A user inserts a pod  200  through the opening  312  of the upper part  302  and pushes the pod through the expanding portion  310  of the collet  305  into a position completely inside the upper part  302 . The evaporator motor is repurposed to rotate the upper part  302  into the lower part  304  once the pod  200  is inserted into the upper part  302 . The evaporator motor continues to drive the upper part  302  into the lower part  304  until torque, voltage, or current reaches a predetermined threshold. At this point, the expanding/contracting portion  310  radially contracts to generate a large frictional fit with the tapered sidewall  208  of the pod  200  to hold the pod  200  in place within the collet evaporator  300 . The evaporator motor stops rotation of the upper part  302  relative to the lower part  304  and locks the pod  200  in place due to this friction. During a freezing cycle, the machine controls refrigerant to flow through the refrigerant channel  306  to exchange heat between the refrigerant and the pod to cool the ingredients within the pod to produce the food or drink. 
     Some systems include a multi-step clamping system due to a change of internal pressure in the pod during the process of making the cooled food or drink. In some of these systems, the evaporator clamps a first time when the pod is under positive pressure due to the pressurized gas in the pod (e.g., before the freezing cycle). During the freezing cycle, a vent port in the pod  200  opens to release the pressurized gas. When the gas is released, the pressure in the pod may drop substantially which can cause the sidewall  208  of the pod  200  to at least partially break free of the grip by the evaporator. The resulting air gap can interfere with heat transfer. 
     The machine controls the evaporator to release the grip and re-clamp on the pod again. This second clamp typically will eliminate any gap between the pod and the evaporator due to the change in internal pressure in the pod. This approach addresses the phenomena that the walls of the pod sometimes bulge slightly outwards when the pod is under positive pressure. As the pressurized gas is released, the pod may shrink to a smaller diameter causing the outer diameter of the pod to pull away from the inner surface of the evaporator. The clamp-and-release approach can reduce or eliminate such air gaps. Some machines control the evaporator to clamp the first time, and when the gas is released, the evaporator clamps further without releasing and then re-clamping. 
       FIG.  15    is a schematic of a refrigeration system of machine  100 . Additional refrigeration systems for machine  100  are described in more detail in U.S. patent application Ser. No. 16/459,388 (attorney docket number 47354-0006001) filed Jul. 1, 2019, U.S. patent application Ser. No. 16/824,616 (attorney docket number 47354-0036001) filed Mar. 19, 2020, and U.S. patent application Ser. No. 17/335,891 (attorney docket number 47354-0037001) filed Jun. 1, 2021, all of which are incorporated herein by reference in their entirety. 
     Refrigeration system  178  includes the evaporator  154 , a condenser  180 , a suction line heat exchanger  182 , an expansion device  184 , and a compressor  186 . The expansion device  184  can include a valve or a capillary tube both of which could be used in the refrigeration system  178 . High-pressure, liquid refrigerant flows from the condenser  180  through the suction line heat exchanger  182  and the expansion device  184  to the evaporator  154 . The expansion device  184  restricts the flow of the liquid refrigerant fluid and lowers the pressure of the liquid refrigerant as it leaves the expansion device  184 . The low-pressure liquid then moves to the evaporator  154  where heat is absorbed from a pod  200  and its contents in the evaporator  154  changes the refrigerant from a liquid to a gas. The gas-phase refrigerant flows from the evaporator  154  to the compressor  186  through the suction line heat exchanger  182 . In the suction line heat exchanger  182 , the cold vapor leaving the evaporator  154  pre-cools the liquid leaving the condenser  180 . The refrigerant enters the compressor  186  as a low-pressure gas and leaves the compressor  186  as a high-pressure gas. The gas then flows to the condenser  180  where heat exchange cools and condenses the refrigerant to a liquid. 
     The refrigeration system  178  optionally includes a first bypass line  188  or valve and second bypass line  190  or valve. The first bypass line  188  directly connects the discharge of the compressor  186  to the inlet of the compressor  186 . Disposed on both the first bypass line and second bypass line are bypass valves that open and close the passage to allow refrigerant bypass flow. Diverting the refrigerant directly from the compressor discharge to the inlet can provide evaporator defrosting and temperature control without injecting hot gas to the evaporator  154 . The first bypass line  188  also provides a means for rapid pressure equalization across the compressor  186 , which allows for rapid restarting (i.e., freezing one pod after another quickly). The second bypass line  190  enables the application of warm gas to the evaporator  154  to defrost the evaporator  154 . The bypass valves may be, for example, solenoid valves or throttle valves. An additional bypass valve can be used (not shown) to direct warm air along the length of the mixing paddle  250  to help remove product sticking to the mixing paddle  250 . 
       FIG.  16    is a plot of machine performance during a freezing cycle  320 . The plot indicates condenser outlet temperature  327 , compressor inlet temperature  325 , evaporator outlet temperature  324 , and evaporator inlet temperature  322  as a function of time. Specifically,  FIG.  16    shows the machine performance for a duration of about 4 minutes and 15 seconds. The freezing cycle  320  begins at about 1 minute (marker  330 ) and ends at about 3 minutes (marker  332 ). During the freezing cycle  320 , refrigerant flows through the evaporator  154  exchanging heat from the ingredients within the pod to the refrigerant while the pod  200  is placed in the evaporator  154 . This causes temperature differences between the evaporator inlet and the evaporator outlet. 
     The first portion  334  of the freezing cycle  320  indicates high heat transfer (e.g., as the ingredients are quickly cooled). The second portion  336  of the freezing cycle  320  indicates low heat transfer (e.g., because the ingredients have already been cooled as indicated by the substantial decrease of the evaporator outlet temperature  324 ). During the second portion  336 , the evaporator outlet temperature  324  and the evaporator inlet temperature  322  substantially converge. In some cases, this means that liquid refrigerant passes through the evaporator  154  and reaches the compressor  186  which is sometimes referred to as flood back. Machine  100  strikes a balance between cooling the pod as quickly as possible while reducing wear and tear on the compressor  186  by tolerating some flood back. 
     In some refrigeration systems, a capillary tube controlled cooling system cannot adjust for large changes in heat load. For example, in portion  334  the high heat transfer leads to high evaporator superheat and, in some cases, it is difficult for the machine to keep up with the heat transfer needed. In portion  336 , the low heat transfer leads to low or no evaporator superheat as explained in the preceding paragraph. 
       FIG.  17    is a schematic of a refrigeration system for machine  100  that includes a refrigerant tank. The machines described in this disclosure include refrigeration systems that include any combination of features described with reference to any of the disclosed refrigeration systems. In some examples, the machines use any combination of features of refrigeration system  178  and  192 . Refrigeration system  192  is similar to refrigeration system  178  except that refrigeration system  192  includes a refrigerant tank  194  connected to the expansion device  184 , the evaporator  154 , and the compressor  186 . The refrigerant tank  194  is fed by the expansion device  184  and refrigerant gas is drawn from the refrigerant tank  194  by the compressor  186 . The refrigerant tank  194  is placed within the machine  100  such that the liquid level of the refrigerant tank  194  is higher (e.g., against gravity) than the evaporator  154 . This means that the evaporator  154  will be filled with refrigerant. This flow arrangement has lower pressure drop (allowing higher flowrates and higher performance) since the compressor  186  does not need to push refrigerant through the evaporator  154 . The evaporator  154  is gravity fed from the refrigerant tank  194 . Refrigeration system  192  maintains a constant supply of refrigerant to boil off and freeze food or drink because the evaporator  154  is always flooded. This increase performance in the early part of a freezing cycle. 
     In some systems, the refrigeration system cools the pod with a compressor using a two-phase refrigerant fluid, such as R1270, R134A, R22, R600a, or R290. In some systems the compressor is a reciprocating compressor or a rotary compressor. Some machines use a cylindrical reciprocating compressor because it fits in the housing of the machine better. Direct Current (DC) compressors with a variable motor speed allow for increased displacement towards the beginning of the refrigeration cooling cycle of the pod (e.g., first 45 seconds of cooling the pod) and slow down the motor speed towards the end of the cooling cycle of the pod in order to increase the efficiency of the freezing process while maintaining the pressure drop. In some systems, the DC compressor can have a variable motor speed that is adjusted depending on the load on the machine&#39;s refrigeration cycle. 
     Some machines described in this disclosure have a compressor that is selected based on the maximum current draw permitted in most modern residential or commercial kitchens or pantries. For example, most modern outlets provide 115 volt and 20 amp service to counter top devices and some older kitchen outlets provide 115 volt and 15 amp service to counter top devices. Some machines use the most powerful compressor possible to achieve the lowest freeze times possible while avoiding current draw over the maximum current draw permitted in these typical outlets (e.g., to avoid tripping electrical circuits). In some examples, the compressor draws 13 amps maximum so that the machine can be powered via a standard wall outlet. 
     Some machines use compressors having a displacement between 10 and 50 cc. For example, some machines use a 13.5 cc compressor, a 16.8 cc compressor, a 33 cc compressor, a compressor with up to 48.6 cc displacement, or a compressor with up to 34.7 cc displacement Some machines use a capillary tube with between 0.05 and 0.07 inch ID (e.g., a 0.050 inch ID, a 0.059 inch ID, a 0.07 inch ID) and between 70 to 100 inches long (e.g., 70 inches long, 90 inches long, or 100 inches long). Some machines use these compressors to achieve a 60 second freeze time for cooled food or drink. The compressors are sized to fit within the housing of the machine, and in some machines, the housing is sized to fit on a kitchen counter and underneath kitchen cupboards. 
     Some machines described in this disclosure include an internal temporary power storage that accommodates any power surge produced when the machine starts up. This helps to avoid drawing current from the kitchen outlet that exceeds the maximum current draw permitted. For example, some machines include a capacitive power buffer to accommodate the start-up power draw of the compressor. When the compressor starts up, it can draw up to 40 amps, so a power storage buffer is advantageous to avoid overloading the circuit. 
     In order to produce consistent ice cream quality/temperatures the machine preferably detects how frozen the product is and ends the cycle at the appropriate time. The machines can use several methods for detecting the progression of the freezing process. One method for detecting progress of the freezing process is to measure the current draw or power used to turn the mixing motor. Thicker ice cream requires more current/power to mix at a given speed. This process however may not be sensitive enough, particularly for drinkable products, where the mixing motor current is relatively low. Several methods can be used to more precisely detect product quality/temperature. 
     One method is to use the PWM (pulse width modulation) speed signal sent to the motor. Some motors control speed by using an encoder and a closed loop motor controller to detect motor speed. For example, the controller reads the encoder speed and then sends a percent of full speed signal (PWM) to the motor to speed up or slow down to achieve the desired speed as detected by the encoder. When mixing products in the machine it is possible to mix at a fixed RPM. When mixing at a fixed RPM the load on the motor increases as the product is frozen. This increase in load requires the controller to send increasingly larger PWM values to the motor for it to maintain constant speed. The PWM value and the difference in PWM value throughout the freezing cycle are better correlated to ice cream final temperature as compared to mixing motor current. 
     Determining when to stop the mixing process and dispense the product is challenging. Some machines use timed cycles, where products are dispensed after a set mixing time (which varies from product to product). Some machines use torque measurements of the drive motor (e.g., drive motor  116 ) to determine when the product has sufficiently thickened. Some machines slow the drive motor to idle periodically and measure the deceleration of the mixing paddle (e.g., mixing paddle  250 ). 
     Typically, a more viscous product slows the mixing paddle faster, and compared to current/torque measurements, this rate of deceleration has been found to be more accurate to gauge product viscosity, which correlates with temperature. For example, in some machines (e.g., machine  100 ), the drive motor is controlled to “coast” for a sample interval of ˜100 mS during each second of the mixing/freezing process. During this sampling interval, software of the machine measures how much the drive motor decelerates from the starting steady state velocity based on rotational velocity measurements provided by an encoder of the machine. After the predefined sample interval completes, the drive motor resumes mixing at a fixed velocity until the next sample period. In some examples, the machine uses an algorithm with a mathematical formula to predict the temperature of the pod (e.g., pod  200  with mixing paddle  250 ) based on the collected velocity data for the most recent sample period and previous sample periods. Once the predicted temperature reaches the target temperature for the pod type, the machine begins the dispensing process to dispense the single serving of the cooled food or drink. 
       FIG.  18    is a view of a pod with a base or lid  220  attached to the first end  204  of the pod  200 . The base  220  is metal (e.g., aluminum) and crimped onto the first end  204  of the pod  200  to form a fluid tight seal with the body  202  of the pod  200 . The base  220  includes a removable protrusion  222  with a weakened score line  224 . In this example, the removable protrusion  222  is integrally formed with the base  220 . The protrusion  222  can be formed, for example, by stamping, deep drawing, or heading a sheet of aluminum being used to form the base  220 . The scoring  224  can be a vertical score into the base of the aluminum sheet or a horizontal score into the wall of the protrusion  222 . For example, the material can be scored from an initial thickness of 0.008 inches to 0.010 inches (e.g., the initial thickness can be 0.008 inches) to a post-scoring thickness of 0.001 inches-0.008 inches (e.g., the score thickness can be 0.002 inches). The weakened score line  224  is 0.006 inches deep into 0.008 inches thick aluminum base lid material. Other caps include a removable protrusion that is inserted into the base  220  after the base  220  is formed instead of being integrally formed with the base  220 . 
       FIG.  19    is a view of example embossments of the lids described in this disclosure. For example, some lids include embossments formed in the lid to strengthen it and reduce the likelihood of doming. Some lids include embossments  431 A,  431 B,  431 C, and/or any of the embodiments similar to the ones shown in  FIG.  25   . 
     A cap  350  is removably attached over the base  220  of the pod  200  after the base  220  is attached (for example, by crimping or seaming) to the body  202  of the pod  200 .  FIG.  18    shows the cap  350  spaced apart from the base  220  for ease of viewing. The machine  100  rotationally engages the cap  350  to rotate the cap  350 . The cap  350  includes one or more drive lugs  356  (e.g., castellations, rooks) that axially extend from the body of the cap  350 . Cap  350  has four drive lugs. The machine  100  engages with the drive lugs  356  to rotationally couple the machine to the cap  350  to rotate the cap  350  relative to the protrusion  222 . The cap  350  engages with the removable protrusion  222  to shear it off of from the base  220  at the weakened score line  224  to form an opening or aperture  226  (at least partially shown in  FIG.  19 E ) in the base  220  of the pod  200 . The aperture  226  is exposed and extends through the base  220  when the protrusion  222  is removed. The machine  100  dispenses the produced food or drink from the pod  200  through the aperture  226 . 
       FIGS.  20 A- 20 G  are perspective views of the cap  350  attached to the base  220  of the pod  200 . The cap  350  is attached to the base  220  by being retained by a radially extending inward lip  358  that circumscribes an inner surface of the cap  350 . Axial movement of the cap  350  to remove the cap  350  from the pod  200  is resisted by engagement of the inward lip  358  with the pod  200 . 
       FIGS.  20 A- 20 G  illustrate rotation of the cap  350  around the first end  204  of the pod  200  to cut and carry away protrusion  222  and expose aperture  226  extending through the base  220 . In some cases, the protrusion  222  and corresponding aperture  226  when the protrusion  222  is sheared and carried away has a surface area between 5% to 30% of the overall pod end surface area. 
     The cap  350  has a first aperture  352  (dispensing aperture) and a second aperture  354  (shearing aperture). The first aperture  352  approximately matches the shape of the aperture  226 . The second aperture  224  has a shape corresponding to two overlapping circles. One of the overlapping circles has a shape that corresponds to the shape of the protrusion  222  and the other of the overlapping circles is slightly smaller. A ramp  360  extends between the outer edges of the two overlapping circles. There is an additional 0.010 to 0.100 inches of material thickness at the top of the ramp transition (e.g., 0.070 inches). This extra height helps to lift and rupture the protrusion&#39;s head and open the aperture  226  during the rotation of the cap  350 . 
       FIGS.  20 A and  20 B  show the cap  350  initially attached to the base  220  with the protrusion  222  aligned with and extending through the larger of the overlapping circles of the second aperture  354 . The machine  100  rotates the cap  350  relative to the pod  200  to cause the ramp  360  to slide under a lip of the protrusion  222  as shown in  FIGS.  20 C and  20 D . Continued rotation of the cap  350  relative to the base  220  of the pod  200  applies a lifting force that separates the protrusion  222  from the remainder of the base  220  (see  FIGS.  20 E- 20 G ) and then aligns the first aperture  352  of the cap  350  with the aperture  226  in the base  220  resulting from removal of the protrusion  222 . Some caps have ramped features that provide a total lift height of approximately 0.075″. Some caps have ramped features that provide a total lift height in a range between approximately 0.05″ and 0.10″. In some machines, the process of removing the protrusion also removes product (frozen or not) that may accumulate within a recess of the end of the protrusion. 
     Some pods include a structure for retaining the protrusion  222  after the protrusion  222  is separated from the base  220 . In the pod  200 , the protrusion  222  has a head  228 , a stem  230 , and a foot  232  (best seen in  FIGS.  20 G and  21 A ). The stem  230  extends between the head  228  and the foot  232  and has a smaller cross-section than the head  228  and the foot  232 . As rotation of the cap  350  separates the protrusion  222  from the remainder of the base  220 , the cap  350  presses laterally against the stem  230  with the head  228  and the foot  232  bracketing the cap  350  along the edges of one of the overlapping circles of the second aperture  354 . This configuration retains the protrusion  222  when the protrusion  222  is separated from the base  220 . Such a configuration reduces the likelihood that the protrusion  222  falls into the waiting receptacle (e.g., bowl or cone) in the dispensing area  110  of the machine  100  when the protrusion  222  is removed from the base  220 . After the mixing paddle  250  of the machine  100  spins and dispenses the produced food or drink through the aperture  226 , a motor of the machine  100  rotates the cap  350  and closes the aperture  226  so that any residual product (e.g., left over ice cream) when melted does not leak out of the pod and contaminate the machine  100 . The pods and machines described in this disclosure are designed to produce and dispense ice cream from the pod without residual product coming into contact with the machine. Machine  100  does not need to be cleaned after each use. 
       FIGS.  21 A- 21 C  are views of the base  220  with the integrally formed protrusion  222 . In some cases, the diameter of the protrusion  222  is 0.375-0.850 inches (e.g., 0.575 inches in diameter). In some cases, an area of the protrusion  222  is 0.1-0.5 in 2  (e.g., 0.26 in 2 ). In some cases, the area of the base  220  is 2.0-5.0 in 2  (e.g. 3.95 in 2 ). The area of the protrusion  222  is a fraction of the total surface area of the base  220 . In some cases, a diameter of the base  220  is 1.5-3.0 inches (e.g., 2.244 inches). In some cases, an area ratio of the protrusion  222  to the base  220  is 0.01-0.50 (e.g., 0.065). 
     In some cases, the protrusion  222  may be circular in shape, have a tear-drop, have a kidney shape, or be of any arbitrary shape. In some cases the protrusion  222  may be round but the scored shape can be either circular in shape, have a tear-drop, have a kidney shape, or be of any arbitrary shape. In some cases, there is no post-stamping scoring but rather the walls are intentionally thinned for ease of rupture. In another version, there is not variable wall thickness but rather the cap  350  combined with force of the machine dispensing mechanism engagement are enough to cut the 0.008 inches to 0.010 inches wall thickness on the protrusion  222 . With the scoring, the protrusion  222  can be lifted and sheared off the base  220  with 5-75 pounds of force, for example between 15-40 pounds of force. 
     In some cases, the protrusion  222  is integrally formed on the base  220  using a mechanical press. This is sometimes difficult to do because it requires a high-load and high-capacity press and many sequential manufacturing operations. It also introduces cold work into the material (e.g., aluminum) which can make the material more brittle and sometimes unable to withstand the cyclical flexing caused by pressurization and de-pressurization of the pod during sterilization, transportation, and storage. Instead of an integrally-formed protrusion, some pods use a protrusion that is separately formed from the base of the pod and adhered (e.g., glued) to the base of the pod. 
     In some cases, a flange of the protrusion is adhered or glued to the underside of the base (e.g., the side toward the inside of the pod) and the top of the protrusion is formed in place after the glue has cured. This requires that the rivet be manufactured consistently every time and glued into the hole consistently. Additionally, the score surrounding the rivet is preferably formed with a consistent depth, which can be challenging to produce consistently. 
       FIGS.  22 A- 22 D  are views of a clinched protrusion design  400  that is used in lieu of gluing a protrusion to a base of the pod. This design uses a mechanical pressing operation (denoted by arrows  406 ) to press a protrusion  402  into a lid  404  sufficiently to form a hermetic seal with the lid without using an adhesive. Further details about the forming operation as described with reference to  FIGS.  23 A- 23 C . The lid  404  is then attached to the first end  204  of the pod  200  to form the base of the pod  200  instead of base  220 .  FIG.  22 A  shows the protrusion  402  before being pressed into the lid  404  and  FIG.  22 B  shows the protrusion  402  after being pressed into the lid  404 . 
       FIGS.  22 C and  22 D  are cross-section views of the lid  404  with the protrusion  402  pressed into place. In these views, the inside of the pod is towards the bottom of the figures. The lid  404  includes a weakened score line  409  that is substantially similar to weakened score line  224 . The weakened score line  224  is outside the radius of the protrusion  402  and surrounds a raised surface  405  in the lid  404 . In some examples, the raised surface  405  is not present and instead the lid  404  is substantially flat. 
     The raised surface  405  is integrally formed with the lid  404  before the protrusion  402  is pressed into place. The raised surface  405  defines a recess  407  for receiving a portion of the protrusion  402  so that the protrusion  402  is biased further away from the body of pod  200 . This allows the protrusion  402  to be positioned in a similar position as protrusion  222  so that protrusion  402  can be interchanged with protrusion  222  and no change to the machine itself needs to be made. A more secure mechanical lock is formed between the lid  404  and the protrusion  402  using the raised surface  405  because a portion of the protrusion  402  is received in the recess  407  of the lid  404 . In some cases, the weakened score line  224  is radially offset from the base of the raised surface  405  to increase the diameter of the aperture. 
     During use, when the machine  100  rotates the cap  350  relative to the lid  404 , an upper lip  408  of the protrusion  402  engages the ramps  360  of the cap  350  to lift the lip  408  upward (e.g., in the direction of arrows  410 ) to remove the protrusion  402  and the raised surface  405  portion of the lid  404  to form an aperture for dispensing produced food or drink. In this way, protrusion  402  functions similarly as protrusion  222 . A difference between protrusion  402  and protrusion  222  is that it is much easier to manufacture lid  404  and protrusion  402  reliably compared to base  220  with protrusion  222  integrally formed. Additionally, the raised surface  405  provides such a secure grip on the protrusion  402  that an adhesive (or glue) is not necessary to ensure that the protrusion  402  remains coupled to the lid  404 . In comparison to the integrally formed protrusion  222 , protrusion  402  may be formed of thicker stock material since it is formed independently of the lid  404  and does not rely upon stretching and thinning of the existing lid material, improving the mechanical integrity of the protrusion  402 . In other examples, the protrusion  402  is pulled out of the raised surface  405  of the lid  404  instead of being torn off via the weakened score line  409 . 
       FIG.  23 A  is a schematic view of a forming operation  470  of the clinched protrusion  402  and a lid  472 . The lid  472  does not have a raised surface. Instead, the lid  472  is substantially flat and/or includes a recessed surface instead of a raised surface. The protrusion  402  is inserted into the tool in the profile shape shown in  FIG.  23 A . A die  478  supports a flange of the protrusion  402  while the protrusion  402  is formed. Punch  474  presses the top of protrusion  402  causing the protrusion  402  to move downward and simultaneously expanding outward towards tool  479 B, which constrains its lateral expansion. Pin  476  is free to move downward with compression of the protrusion  402 . Punch  474  is limited in its downward motion due to a diametrical expansion at taper  474 A, and defines the height of the protrusion. Various other tools  479 A,  479 B support the punch  474  and the lid  472  during the forming operation. 
       FIGS.  23 B and  23 C  are schematic views of a forming operation  480  for forming a raised surface of the lid.  FIG.  23 B  represents the start of the forming operation and  FIG.  23 C  represents the end of the forming operation. When formed, the lid  404  includes the raised surface  405  described with reference to  FIG.  22 C . The lid  404  is substantially flat in the initial stage shown in  FIG.  23 A . Once the raised surface  405  is formed, the protrusion  402  is clinched using the forming operation  470  described with reference to  FIG.  23 A . A pair of dies  482 ,  484  sandwich the lid  404 . A lower tool  486  remains fixed in place while the pair of dies  482 ,  484  move downward so that the raised surface  405  is formed on the pin  488 . As the portion of the lid  404  deforms, the punch  490  forms the shape of the portion of the lid  404  into the raised surface  405 . An upper tool  492  supports the upper die  484 . 
       FIGS.  24 A and  24 B  are perspective views of a riveted protrusion design  420  where a protrusion  422  is riveted into place. As with the clinched protrusion design  400 , the riveted protrusion design  420  is much easier to form than the integrally-formed protrusion  222  and is much less complicated than gluing a protrusion in place on the lid. A weakened score line  423  (schematically shown) surrounds the protrusion  422 . During use, the machine  100  rotates the cap  350  so the ramps  360  engage a lip of the riveted protrusion  422  in a similar manner as protrusions  222  and  402 . This engagement causes the riveted protrusion  422  and a portion of the lid  424  inside the area of the weakened score line  423  to detach from the lid  424  leaving an opening for cooled food and drink to be dispensed from the pod  200 . In some cases, the protrusion  422  is a pre-formed rivet. 
     The clinched protrusion design  400  and the riveted protrusion design  420  have numerous advantages compared to an integrally-formed protrusion (e.g., protrusion  222 ). First, the protrusions are formed in a separate manufacturing operation which allows them to be designed with more complicated sizes and shapes. For example, the protrusion does not need to be round, which benefits registering and aligning the protrusion in the shear mechanism. In some cases, the protrusion is shaped as a ski-type feature for increased lift. Example ski-type features as described with reference to  FIG.  25   . Second, since the base itself does not need to undergo a large cold-work press operation, the material of the base preserves strength and integrity. Third, the manufacturing operations for forming the protrusion separately and then performing a riveting operation are considerably simpler. 
       FIG.  25    is a perspective view of a ski-type protrusion design  425  where a protrusion  426  is coupled to the surface of a lid  428  of a pod (e.g., pod  200 ). In some examples, the protrusion  426  is coupled to the lid  428  via pressing, clinching, riveting, or adhering. A weakened score line  427  surrounds the protrusion  426 . During use, the machine  100  rotates a cap (e.g., cap  350 ) so the ramps  360  of the cap  350  engage each of two lips  429  of the ski-type protrusion  426  in a similar manner as protrusions  222  and  402 . This engagement causes the ski-type protrusion  426  and a portion of the lid  428  inside the area of the weakened score line  427  to detach from the remainder of the lid  428  leaving an opening for cooled food and drink to be dispensed from the pod  200 . 
     A difference of the ski-type protrusion  426  compared to protrusions  222 ,  402 , and  422 , is that the lips  429  are shaped to match the curvature of the ramps  360  of the cap  350 . For example, the lips  429  are arced to match the ramps  360  and increase the contact area between the protrusion  426  and the ramps  360 . This increases reliability of the shearing process. The ski-type protrusion  426  is also an example of a non-circular protrusion. Specifically, the ski-type protrusion  426  is shaped as a truncated wedge. 
     Some pods include other protrusion designs and other approaches for separating the protrusion from the base of the pod. For example, in some pods, the base has a rotatable cutting mechanism riveted to the base. The rotatable cutting mechanism has a shape similar to that described relative to cap but this secondary piece is riveted to and located within the perimeter of base rather than being mounted over and around base. When the refrigeration cycle is complete, the processor of the machine activates an arm of the machine to rotate the riveted cutting mechanism around a rivet. During rotation, the cutting mechanism engages, cuts, and carries away the protrusion, leaving the aperture of base in its place. 
     Some pods are pressurized to have an internal pressure of around 5-100 psi gauge pressure. In some examples, the pod is filled with between 10-20 psi of overpressure. For example, when the pod is filled, the pod is dosed with an inert gas (e.g., nitrogen) which pressurizes the pod and causes an outward bulge in the base of the pod. Due to these pressures, the base of the pod tends to bow outward after the pod is filled and pressurized. This can cause an engagement issue with the ramped features of the cap and can potentially lead to the protrusion being removed prematurely or not being removed at all. 
     To complicate the issue, the pod further undergoes a sterilization process that subjects the pods to high temperatures and additional cyclical pressure changes in a retort chamber due to differential pressures between the pod interior and the surrounding retort environment. In some cases, this results in additional outward bowing of the base. When the pod is then inserted into the machine  100  and the drive shaft engages the drive head of the mixing paddle, a seal of the pod is broken and the pressurized nitrogen gas contained within the pod escapes from the pod, at least partially relaxing the base. Differences in curvature between a curved base and a flat shearing cap can present a mismatch/misalignment that can interfere with the protrusion being sheared properly. 
       FIGS.  26 A- 26 D  are views of a domed cap assembly  450 . The domed cap assembly  450  includes a shearing cap  460 . The cap  460  includes a body  462  and a domed insert  464  rotationally coupled to the body  462  of the cap  460 . The domed insert  464  includes a domed ramp  465  that is sized to engage the protrusion of the base of the pod when the base is domed into a similar shape as the domed insert  464 . 
     The domed insert  464  is manufactured with a domed shape representing an expected dome shape of the base of the pod after the pod is pressurized by nitrogen (e.g., after liquid nitrogen is dosed into the pod and the pod is sealed). For example, initially the base  452  of a pod (e.g., substantially the same as base  220  of pod  200 ) is substantially flat or planar. When the pod is dosed with liquid nitrogen and the base is attached to the body of the pod (e.g., by crimping) to seal the contents of the pod, the pod becomes internally pressurized by an expansion of the nitrogen as it warms to room temperature. When the domed shearing cap  460  is used, the base  452  bows from its initial flat shape to a final bowed shape that approximately matches the pre-domed shape of the domed insert  464 . As a result, when the base  452  and domed insert  464  are in contact with each other as shown in  FIG.  26 A , the perhaps angled and/or deformed protrusion  468  engages the domed ramps  465  of the domed insert  464  which provides a better and more reliable engagement than if a flat cap and ramps were used instead of the domed shearing cap  460 . 
       FIG.  26 A  shows the base  452  before it is attached to a pod (e.g., the body of a pod is not shown in  FIG.  26 A ) and while it is in contact with the domed insert  464  of the domed shearing cap  460 .  FIGS.  26 B- 26 D  are engineering drawings of the domed insert  464 . The central region  454  of the domed insert  464  is domed by about 0.043 inches (e.g., between 0.040 and 0.045 inches) but can be domed to other dimensions to match the bowed base  452  depending on the pressurization level of the pod. The insert  464  is formed of metal (e.g., Aluminum 6061-T6 alloy) and, in some cases, is anodized (e.g., MIL-STD-8625 Type II clear coating). 
       FIGS.  27 A- 27 E  are views of peel-back lid design  500  that includes a surface  502  (or tab) that is “peeled-back” instead of a protrusion that is sheared off completely. The surface  502  is integrally formed on a lid  504  for the pod  200 . The surface  502  is substantially flat except for a raised protrusion  506  located on one side of the surface  502 . The surface  502  is at least 75% surrounded by a weakened score line  508 . A small non-scored region  510  keeps the surface  502  attached to the lid  504  and retains the surface  502  on the lid  504  so the surface  502  does not completely detach from the lid  504  and fall into the pod or into the dispensed product. The surface  502  is biased to one side of the lid  504 . 
       FIG.  27 B  is a view of a pod  200  with the lid  504  attached to the end of the pod  200 . The surface  502  is shown in the peeled-back state to define an aperture  512  for dispensing produced food or drink from the pod  200 . The surface  502  is bent and resides on the outside of the pod  200 . This is in contrast to traditional beverage cans where a tab is pushed into the can—not out of the can. 
       FIGS.  28 A- 28 C  are a sequence of views showing a cap  520  attached to the pod  200  that has the lid  504  attached. The cap  520  is substantially similar to cap  350  except that instead of having ramps  360  that engage the protrusion  222  to shear it off, cap  520  includes a raking surface  522  that engages the raised protrusion  506  to peel it back. The raking surface  522  is integrally formed with the body of the cap  520 . The raking surface  522  is angled at a 60 degree angle relative to the plane of the lid  504 . Some caps have a raking surface that is angled between 45 degrees and 80 degrees relative to the plane of the lid  504 . The machine  100  rotates the cap  520  relative to the lid  504  to cause the raking surface  522  to engage the raised protrusion  506 . The raking surface  522  includes a sharp edge  526  on the bottom that rides along the lid  504 . The sharp edge  526  is a knife edge to assist in breaking or slicing the weakened score line  508  as the cap  520  rotates relative to the lid  504 . 
       FIGS.  28 A- 28 C  each represent a different angular orientation of the cap  520  relative to the lid  504 .  FIG.  28 A  shows the surface  502  in its initial position where it seals the pod and there is no opening on the lid  504 .  FIG.  28 B  shows the raking surface  522  engaging the raised protrusion  506  to lift the surface  502  into a first intermediate position where the pod is partially open. The surface  502  pivots open on an axis  524  located on the side opposite to the raised protrusion  506 .  FIG.  28 C  shows the raking surface  522  engaging a portion of the surface  502  to further lift the surface  502  into a second intermediate position. The cap  520  continues to rotate relative to the lid  504  until the surface  502  is completely folded back on the lid  504  like the position shown in  FIG.  27 B . 
     While the cap  520  is shown with four  528  drive lugs, some caps compatible with the peel-back lid design  500  include a castellation design similar to the design of cap assembly  430  shown in  FIGS.  42 A- 42 E . Cap  520  is shown without a dispensing port for illustrative purposes. Some caps compatible with the peel-back lid design  500  include dispensing port like cap  350 . 
     Some pods have caps with a raking surface that moves linearly across the lid (e.g., slides diametrically straight across the lid) to remove the protrusion like the protrusion  222  and/or a surface like the surface  502 . The raking surface slides across the lid to separate, remove, and collect the protrusion and/or surface. Some machines include a raking surface in the machine instead of the cap. Some caps include a raking surface that is mounted as a secondary piece within cap of the pod (e.g., like the insert  434 ) and not integrally formed with the body of the cap. Some lids include a raking surface that is integrally formed with the lid. 
       FIGS.  29 A- 29 D  are schematic views of a peel back lid design  530  with a raking surface that includes a cavity. The peel back lid assembly  530  includes a lid  532  that is substantially similar to lid  504 . However, instead of using a cap  520  with a raking surface  522  to engage a protrusion, the lid  532  includes a part  534  that is pinned to the center of the lid  532  (via pin  536 ). Part  534  includes a raking surface  538  that engages a protrusion  540  of the lid  532 . Part  534  includes a cavity that captures the peeled back protrusion  540  (“hanging chad”) in a cavity (e.g., between a lower and upper portion) as the part  534  rotates relative to the lid  532  (e.g., as the part  534  moves in the direction of arrow  539  with respect to the lid  532 ). Some machines include a motor coupled to the part  534  to cause it to rotate. 
     An advantage of the peel back lid design  530  is that a shearing cap is not required. Another advantage of the peel back lid design  530  is that by capturing the peeled back protrusion  540  in the cavity, interaction with dispensing ice cream is reduced. In some examples, the hidden peeled back protrusion  540  avoids it from cutting the dispensed ice cream and/or capturing the residual food or drink. In some examples, the peeled back protrusion  540  does not come into contact with the cooled food or drink. 
       FIGS.  30 A- 30 D  are perspective views of an alternate two-piece shearing cap  550  for a pod. The two-piece shearing cap  550  includes a body  554  (e.g., a plastic drip tray) and a shearing ramp insert  552 . Insert  552  is substantially flat and planar and is removably attachable to the cap body  554 . Insert  552  attaches to the cap body  554  into the assembled position shown in  FIG.  30 A . 
     The insert  552  includes mating features  560  arranged on an outside diameter of the insert  552  for mating the insert  552  to the cap body  554 . The mating features  560  include one or more faces that engage the cap body  554  to transfer torque between the cap body  554  and the insert  552 . The mating features  560  of the insert  552  include a wavy (or cyclical/undulating) pattern of radially outward protrusions that circumscribe the insert  552 . In some examples, the mating features  560  include 12 equally-spaced radially outward protrusions representing peaks with troughs between each respective peak. Other shapes are possible, such as squares, rectangles, or triangles, so long as they allow torque transfer between the cap body  554  and the insert  552 . The cap body  554  includes a recess  561  having a wall with a corresponding pattern of the mating features  560 . When the insert  552  is inserted into the cap body  554 , the insert  552  is rotationally coupled to the cap body  554  due to an engagement between the mating features  560  of the insert  552  and the walls of the recess  561 . 
     The insert  552  includes two apertures. A first aperture is a wide mouth aperture  556  that allows product to pass through when dispensing it from the pod. The first aperture  556  is sufficiently large that it accommodates various dispensing orifices (e.g., orifice  564 ) so that a single design of the insert  552  is compatible with various shapes of dispensing orifices (e.g., square, tri-lobe, penta-lobe, star, elliptical, circular, etc.) and sizes of dispensing orifices. Example shapes and sizes of dispensing orifices are shown in  FIGS.  31 A- 31 C . 
     The insert  552  includes a ramped surface  558  for removing the protrusion to open the pod. For example, the ramped surface  558  includes a protrusion shearing ramp to remove a protrusion from a pod in a similar manner as ramps  360  of cap  350 . Shearing cap  550  includes a lower profile ramped surface  558  than cap  350 . The ramped surface  558  surrounds a second aperture  559  of the insert  552 . In some examples, the insert  552  is metal (e.g., stamped metal such as stamped aluminum, machined aluminum, cast aluminum, etc.) and the cap body  554  is plastic (e.g., injection molded plastic). In some cases, the insert  552  is axially retained in the cap body  554  using a press fit (e.g., an interference fit) between the mating features  560  of the insert  552  and the recess  561  of the cap body  554 . Some caps use other retention features (e.g., snap ring, adhesive, etc.). In some cases, manufacturing the insert  552  with the second aperture  559  can be cheaper and/or easier than other solutions (e.g., blind holes, recesses, etc.). 
     Some shearing caps include a recess instead of the aperture  559 . For example, a recess works because an insert just needs to clear the protrusion (e.g., protrusion  222 ) from the pod as the protrusion head rides along the ramped surface  558 . 
     The cap body  554  includes a recess  562  (e.g., a drip reservoir) to capture melting residual product left in the pod after the machine dispenses the majority of the product from the pod. The recess  562  is integrally formed with the cap body  554 . The cap body  554  includes an orifice  564  defining a pass-through for product to pass as the product dispenses from a pod. In this example, the orifice  564  is square-star shaped but other shapes can also be used as described with reference to  FIGS.  31 A- 31 C . 
     The cap body  554  includes a ridge feature  566  that retains the shearing cap  550  in position on the rim of a pod. The ridge feature  566  is a radially-inward extending protrusion that is located on an inner surface  567  of the cap body  554 . For example, when the shearing cap  550  is installed onto an end of the pod (e.g., in a factory during an assembly process or by a consumer), the ridge feature  566  engages the rim of the pod and, upon sufficient force applied by the user, the rim snaps past the ridge feature  566 . This snap fit holds the shearing cap  550  onto the pod but allows a user to remove the shearing cap  550  from the pod if needed. In some examples, the size of the ridge feature  566  is sufficient to retain the insert  552  in the cap body  554  (e.g., so the insert  552  does not fall out of the cap body  554  during handling of the cap  550  before the cap  550  is installed on the rim of the pod). 
     The cap body  554  includes a recess  570  that includes the orifice  564 . The cap body  554  includes four drive lugs  572  (or drive protrusions) that engage a cap shearing mechanism of the machine  100  to rotate the shearing cap  550  with respect to the pod to shear off the protrusion of the pod and form an opening. 
     The drive lugs  572  axially protrude from the cap body  554  up to a surface  573 . This surface  573  is also the same surface that defines the recess  570  and is the furthest-most surface away from the pod. This feature is advantageous because the chances of residual product leaking from the shearing cap  550  onto the drive mechanism, evaporator, or other parts of the machine is reduced when the shearing cap  550  includes a cap body  554  having an end surface of the drive lugs  572  and the surface defining the recess  570  share the same plane. Examples of this advantage are shown and described with reference to  FIGS.  37 A- 38 B . 
     The cap body  554  includes an aesthetic sealing skirt  574  that further protects the machine  100  from coming into contact with the residual product of the pod. The skirt  574  is a cylindrical surface that extends along a longitudinal direction of the cap body  554  and covers the first end  204  of the pod  200  when installed on the pod  200 . The ridge feature  566  is located on an inner surface  567  of the skirt  574  to snap over the rim of the pod for retention and sealing against the pod. In some examples, the skirt  574  serves as a secondary catch if the protrusion of the pod is not retained by the cap  550 . This reduces the chances of a completely detached protrusion ending up in the product being dispensed. 
       FIGS.  31 A- 31 C  are perspective views of a shearing cap for a pod with various size orifices.  FIG.  31 A  is a view of a shearing cap  590  with a square-star orifice  592 ,  FIG.  31 B  is a view of a shearing cap  594  with a droplet orifice  596 , and  FIG.  31 C  is a view of a shearing cap  598  with triangle orifice  599 . Some shearing caps include other orifices (e.g., circular, elliptical, diamond, trapezoidal, star, pentagon, etc.). 
       FIGS.  32 A- 32 E  are perspective views of a three-piece shearing cap  600  for a pod. The shearing cap  600  includes a drip tray  602 , a shearing insert  604 , and a cap body  606  (base sealing skirt). In some examples, the drip tray  602  and/or the cap body  606  is/are plastic (e.g., injection molded plastic). In some examples, the insert  604  is metal (e.g., stamped, machined, or cast aluminum). In some examples, the insert  604  is substantially flat and thin. 
     The insert  604  includes a ramped surface  608  (e.g., a shearing surface) like insert  552 . The insert  604  is insertable within the cap body  606 . The drip tray  602  includes a circumferential seal  610  that slides into the cap body  606  and seals (or substantially seals) the shearing cap  600  to the pod to retain/capture the drips of residual product as the product is dispensed and after the product has melted after dispensing. An advantage of the three-piece shearing cap  600  is that the shearing ramp  608  can be formed using a stamping process which reduces the cost of manufacturing the insert  604 . 
     In some examples, the circumferential seal  610  is over-molded onto a body of the drip tray  602 . The drip tray  602  is removable from the cap body  606  and can be exchanged as needed. The insert  604  includes a pair of snap features  612  (e.g., as shown in  FIG.  32 D ) that engage an inner recess of the cap body  606  to releasably hold the insert  604  to the cap body  606 . Some inserts include a pair of snap features, as shown, or more than two (e.g., 3-10 snap features equally spaced around the circumference of the insert. 
     The cap body  606  includes a cylindrical surface  614  to prevent (or reduce) product from leaking from the lateral sides of the pod during and after dispensing. The cap body  606  includes a sealing/retention ridge  605  located on an inside of the cap body  606  and integrally formed with the cap body  606 . The sealing/retention ridge  605  seals the cap body  606  to the pod and snaps over rim at the first end  204  of the pod  200  to secure the cap body  606  onto the pod  200 . 
       FIGS.  33 A and  33 B  are perspective views of an alternate two-piece shearing cap  630  for a pod. The shearing cap  630  includes a cap body  632  and a seal insert  634 . The cap body  632  includes a large opening  636  to accommodate the seal insert  634 . In some examples, the seal insert  634  is resilient and made of an elastomer (e.g., rubber, nitrile, silicone, etc.). In some examples, the seal insert  634  is made of plastic (e.g., polypropylene). The insert  634  is preferably removable from the cap body  632  only by sufficient force to reduce the risk of a choking hazard. In some examples, the insert  634  is adhered to the cap body  632  or snaps into place using an interference fit. 
     The seal insert  634  includes dispensing port  638  in the form of a star orifice. The star orifice defines a passageway for product to flow out of the pod. While a star orifice  638  is explicitly shown, some shearing caps include other orifice sizes (e.g., circular, elliptical, diamond, trapezoidal, star, pentagon, etc.). The seal insert  634  is a cost effective way to use different sized orifices with different pods and eliminate product from squirting laterally from the cap body  632  when the product is dispensed from the machine  100 . This helps to avoid situations where residual product contacts the machine  100  during mixing and/or dispensing. 
     When the seal insert  634  is attached to the cap body  632  (e.g., as shown in  FIG.  33 A ) and installed on the first end  204  of the pod  200 , the seal insert  634  seals tightly against a base  220  of the pod  200  and occupies the large opening  636  in the shearing cap  630 . This tight seal is advantageous because the seal prevents (or substantially prevents) product from squirting laterally as the product is dispensed. 
     The cap body  632  includes a knurled skirt  639  that increases the frictional engagement with a shearing mechanism of the machine  100  to rotate the shearing cap  630  with respect to the base of the pod to remove the protrusion of the pod. While shearing cap  630  includes a knurled skirt  639 , other shearing caps include a scored skirt or otherwise a skirt with a rough surface finish to facilitate engagement with a shearing mechanism. 
       FIGS.  34 A- 34 C  are views of an alternate two-piece shearing cap  660  for a pod. The shearing cap  660  is substantially similar to shearing cap  550  except for the following differences. The shearing cap  660  includes a cap body  662  (drip tray) with a tri-port aperture  668 . The cap body  662  includes three equally-spaced tangs  664  (e.g., spaced approximately 120 degrees apart) that are integrally formed on the cap body  662  radially extend into the center of the aperture  668  and are biased in an axial direction away from the pod. The tangs  664  serve as a safety feature that prevents consumers from sticking their fingers through the aperture  668  and potentially injuring themselves on sharp edges surrounding the aperture on the base of the pod or coming into contact with a rotating mixing paddle or impeller. In some cases, less than three or more than three tangs  664  are used. For example, some shearing caps include two tangs and some shearing caps include four tangs. Other shearing caps can include more than four tangs (e.g., five tangs, six tangs, etc.). The tangs  664  are specifically shaped to create a particular pattern of the product stream as the product is dispensed from the machine  100 . 
       FIG.  35    is an image of product  690  being dispensed from a machine  692  through the shearing cap  660 . The machine  692  is the same as, or substantially similar to machine  100 . The machine  692  is operable to dispense product  690  (in this example, a frozen confection such as ice cream) having a particular texture (or pattern) because the product  690  passes through the three tangs  664  of the tri-port aperture  668  of shearing cap  660 . In this example, the three tangs  664  produce a tri-lobe texture. In other examples, other variations of tangs produce other textures. For example, a five tang design produces a penta-lobe texture. The product  690  is being dispensed into a cup  694  that is resting in the dispensing area  696  of the machine  692 . The dispensing area  696  of machine  692  is similar to the dispensing area  110  of machine  100 . After the machine  692  completes the dispensing process, a user removes the cup  694  from a base of the machine  692  and consumes the product  690  using a spoon. 
     Referring to  FIGS.  34 A- 34 C , the cap body  662  includes four drive lugs  670  that protrude from an annular surface  672 . While shearing cap  550  includes drive lugs  572  that includes an end surface that shares the surface  573  with the recess  570 , shearing cap  660  does not have this property. Instead, the drive lugs  670  protrude a distance less than the furthest-most surface  672 . The advantage of reducing the chances of product escaping from the shearing cap  660  onto the drive mechanism and/or other parts of the machine  100  is still achieved because there is essentially no space for residual product to escape from the recess  674  that defines the tri-lobed aperture  668  when the pod is installed into the machine  100 . While the cap body  662  includes the drive lugs  670 , some caps include a plurality of axially extending protrusions and recesses like cap assembly  760  shown in  FIGS.  39 A- 39 C  or cap assembly  430  shown in  FIGS.  42 A- 42 E . Some versions of cap  550  have drive lugs that include an end surface that shares the surface such that the drive lugs  670  protrude a distance equal to the furthest-most surface. 
       FIG.  34 C  is a cross-section perspective view of the shearing cap  660 . The shearing cap  660  includes an insert  676  that is substantially similar to insert  552 . An annular space between the skirt  678  of the cap body  662  and the insert  676  defines a radial labyrinth channel  680 . The radial labyrinth channel  680  prevents product from escaping to the sidewall of the pod. The cap body  662  includes a recess  682  (e.g., a drip tray or reservoir) substantially the same as the recess  562  of cap  550 . Together, the recess  682  and the labyrinth channel  680  help reduce product from escaping from an interior of the shearing cap  660  when the product is being dispensed from the machine  100 . This improves cleanliness of the dispensing process and also reduces the chances of product contaminating parts of the machine  100 . 
       FIGS.  36 A and  36 B  are images of a prototype two-piece shearing cap  700 . The shearing cap  700  is substantially similar to shearing cap  660 . The shearing cap  700  includes a cap body  702  (or drip tray) made of plastic and printed using a 3D printer. The shearing cap  700  includes an insert  704  made of aluminum metal and machined using a CNC machine. A ruler  706  depicts the physical size of the shearing cap  700 . For example, the shearing cap  700  is about 2 inches (5.08 cm) in diameter. 
       FIGS.  37 A and  37 B  are perspective views of a pod  722  with a shearing cap  720  installed on an end of the pod  722 . The shearing cap  720  is substantially the same as shearing cap  350  and the pod  722  is substantially the same as pod  200 .  FIGS.  37 A and  37 B  represent a state after the product has been dispensed from the pod  722  and the pod  722  has been removed from the machine  100 . For example, it is possible for residual product  724  to escape from the shearing cap  720 . In some cases, product  724  reaches a recessed surface  726  between the drive lugs  728 . In some cases, product  724  goes beyond this recessed surface  726  and reaches the outer sides of the skirt of the shearing cap  720 . When this happens, product  724  may contaminate the shearing mechanism and/or other parts of the machine which is not desired. 
       FIGS.  38 A and  38 B  are perspective views of a pod  742  with the shearing cap  740  installed. The shearing cap  740  is substantially the same as shearing caps  660  and  700  and the pod  742  is substantially the same as pod  200 . Much less product  744  escapes from the shearing cap  740  (e.g., compared to the shearing cap  720 ) when product is dispensed from the machine  100 .  FIGS.  38 A and  38 B  represent a state after the product  744  has been dispensed from the pod  742  and the pod  742  has been removed from the machine  100 . Much less product  744  escapes from the shearing cap  740  at least in part due to the product being confined to the recess  746  of the shearing cap  740 . In addition, having a radial labyrinth channel (e.g., channel  680 ) and a drip reservoir (e.g., recess  682 ) helps reduce the chances of product  744  escaping from the interior of the shearing cap  740 . 
       FIGS.  39 A- 39 D  are perspective views of a three-piece over-molded shearing cap  760  for a pod. Shearing cap  760  includes a cap body  762  (or drip tray or shear tray), an insert  764  over-molded with the cap body  762 , and a cover  766  located within a recess  768  of the shear tray and at least partially covering the insert  764 . The cover  766  has a wall  770  that contacts the inner surface of the recess  768  to concentrically position the cover  766  within the cap body  762 . 
     The insert  764  includes a first aperture  772  and a second aperture  774 , and the first aperture  772  includes ramp features  784  to engage the protrusion of the pod. One or more tangs  776  are integrally formed on the insert  764  instead of the tangs being on the cap body. Shearing cap  760  includes three tangs that are directed radially inward and are equally spaced around the circumference of the second aperture  774 . The second aperture  774  is used as a dispensing port  774  and is radially offset from the center of the insert  764 . Because the insert  764  rotates with respect to the pod, the dispensing port  774  moves circumferentially around the cap  760  when the machine  100  rotates the cap  760  relative to the base of the pod. The dispensing port  774  moves to a position where it is axially aligned with the opening of the base. 
     The insert  764  is over-molded with the cap body  762  at one or more locations around the circumference of the insert  764 . The insert  764  includes one or more mating features  778  that are over-molded with the cap body  762  to rotationally couple the insert  764  to the cap body  762 . The mating features  778  include protrusions that extend radially outward and are angled relative to the plane of the insert  764 . 
     The cover  766  includes a drip reservoir  780  (drip tray) to capture dripping product (e.g., melted food or drink) during and after the food or drink is dispensed from the machine. In some cases, the drip reservoir  780  acts as a backup to retain the protrusion of the pod in situations where the protrusion is inadvertently freed from engagement with the ramp features  784 . Usually the protrusion is retained by the ramp features  784  and is not released after it is sheared off from the pod so it does not fall into the dispensed product. The drip reservoir  780  is an enlarged recessed area sized to completely cover the first aperture  772  so there is little risk that residual product seeps beyond the cover  766  once the protrusion has been sheared off from the pod. 
     The cover  766  includes alignment features  782 A,  782 B to assist in locating the protrusion of the pod with respect to the cap  760  when the cap  760  is installed on the rim at the first end  204  of the pod  200 . This helps to ensure that the protrusion of the pod is in the proper position relative to the ramp features  784  of the insert  764  before the machine  100  begins to rotate the cap  760  to shear the protrusion during the dispensing process. The alignment features  782 A,  782 B are axially extending protrusions that extend toward the pod from a bottom surface of the drip reservoir  780 . When the cap  760  is installed on a pod having a protrusion, the protrusion would be located within the circled region  788  between the two alignment features  782 A,  782 B. Alignment feature  782 A makes sure that the protrusion is far enough up the ramp  784  to engage the ramp  784  and not slip out. Alignment feature  782 B keeps the protrusion from going too far up the ramp  784 . Alignment feature  782 B is bendable so that it provides a “soft” stop when assembling, but will bend out of the way during the shearing process. 
     In some examples, the cap body  762  and the cover  766  are formed of plastic (e.g., polypropylene). In some examples, the insert  764  is formed of metal (e.g., aluminum). Some caps use a removable insert instead of an over-molded insert to facilitate easier removal of the insert from the cap body so the insert can be recycled. In some examples, the removable insert is installed using snap-fit features, a screw-on design (e.g., one or more threads), and/or pins/stakes. Some caps use an aluminum body  762  so that the body  762  and the insert  764  can be easily recycled together without requiring them to be separated. Some caps further use an aluminum cover  766  so that the aluminum cap body  762 , the aluminum insert  764 , and the aluminum cover  766  can be recycled together without requiring them to be separated. 
       FIGS.  40 A- 40 C  are perspective views of a prototype shearing cap  800  that is similar to shearing cap  660  but the tang features  664  are formed on an insert that is disposed on the inside of the cap. Cap  800  includes a cap body  802  (or drip tray or shear tray), a first insert  804  rotationally coupled to the cap body  802 , and a second insert  808  located within a recess  806  of the cap body  802  and an opening in the first insert  804 .  FIG.  30 C  shows the second insert  808  visible through an opening  812  in the cap body  802 . The second insert  808  includes a protrusion stop  810  that extends into the region of the ramped surface  814 . The protrusion stop  810  ensures that the protrusion of the pod (e.g., protrusion  222  of pod  200 ) is far enough up the ramp  814  for engagement and not slip out. In this way, protrusion stop  810  serves the same function and purpose as alignment feature  782 A of cap  760 . 
       FIGS.  41 A- 41 C  are perspective views of a prototype shearing cap  815  that is similar to the three-piece over-molded shearing cap  760  but includes a different ramped surface that engages the protrusion of the pod. Cap  815  includes a cap body  816  (or drip tray or shear tray), a first insert  818  rotationally coupled to the cap body  816  via overmolding, and a second insert  820  located within a recess  819  of the cap body  816 . As shown in  FIG.  41 A , the ramped feature is coincident with the plane of the insert  818  at side  822 A and gradually extends out of the plane of the insert  818  in the direction away from the pod (if the cap were inserted on the pod) at side  822 B.  FIG.  41 B  shows the opposite view as  FIG.  41 A . As shown in  FIG.  41 B , side  822 B of the ramped feature protrudes in the direction out of the page (e.g., toward a viewer viewing  FIG.  41 B  on the page). In some cases, caps with ramped features that protrude out of the plane of the insert  818  as shown in  FIGS.  41 A and  41 B  more reliability shear off the protrusion of the pod than caps without such a feature. 
       FIGS.  42 A- 42 E  are perspective views of a prototype cap assembly  430 . Cap assembly  430  includes a shearing cap  432  and a shear drive insert  434 . A protrusion  436  (which has already been detached from a base of a pod) is shown engaged with the shearing ramps  438  of the insert  434 . The insert  434  includes a dimple  440  located in the center of the insert  434 . An end surface of the dimple  440  contacts the base of the pod and provides a downward force on the base of the pod as the insert  434  is rotated. This force prevents the base of the pod from lifting up together with the protrusion  436 . This allows a weakened score line  442  surrounding the protrusion  436  to fracture more effectively. The dimple  440  pushes down on the base immediately adjacent to the weakened score line  442  to increase the shearing stress at the weakened score line  442 . While insert  434  includes one dimple  440  some inserts include more than one dimple (e.g., 2-10 dimples). 
       FIGS.  43 A- 43 D  show a cap shearing system  830  that is part of the machine  100 . The cap shearing system  830  is part of a machine-pod interface and dispensing system of the machine  100 . In the position shown in  FIG.  43 A , the pod  200  is inserted into the machine  100  and is in contact with the cap shearing system  830 . The evaporator  154  surrounds the pod  200  (e.g., as shown in  FIG.  10 A ) but is not shown for clarity. The pod  200  includes a mixing paddle  250  and a drive head  252  as described with reference to  FIG.  2   . 
     Shearing cap  350  is installed on the first end of the pod  200  and is in engagement with the cap shearing system  830 . In this example, the drive lugs of the shearing cap  350  are received in recesses  840  of an annular member  832  (rivet shear hub) of the cap shearing system  830  when the pod  200  is inserted into the machine  100  in the position shown in  FIG.  43 A . Engagement between the drive lugs of the shearing cap  350  and the annular member  832  rotationally couple the shearing cap  350  to the machine  100 . 
       FIG.  43 B  shows the cap shearing system  830  without a pod inserted into the machine  100 . Three iris fingers  834  (pawls) are positioned radially around the circumference of annular member  832  and located relative to the annular member  832  by pivot pins and bearings. The pivot pins and bearings create a lever arm  836 . The ends of the iris fingers opposite the levers  836  are connected to a spur gear  838  via links, creating a kinematic linkage. As spur gear  838  rotates, the corresponding motion of the links causes the iris fingers  834  to rotate radially inward toward the center of the annular member  832 , generating a torsional force on the shearing cap  350  as the iris fingers  834  come into contact with it. The spur gear  838  has a rotational degree of freedom with respect to the annular member  832  which allows it to rotate freely a fixed distance to permit iris fingers  834  to actuate and engage the shearing cap. 
     The body of pod  200  is clamped in evaporator  154  (e.g., by a compressional squeezing force applied by the evaporator  154  when it closes). A shearing motor  842  is rotationally coupled to the annular member  832  to cause it to rotate. The torsional force exerted by the cap shearing system  830  causes the shearing cap  350  to rotate relative to the body of the pod  200  to separate the protrusion (e.g., protrusion  222 ) from the pod  200  to reveal an aperture for dispensing the cooled food or drink. 
     The annular member  832  is mounted in a one-way clutch mechanism that permits freedom of movement in the counterclockwise rotational direction but inhibits movement of the annular member  832  in the clockwise rotational direction. When spur gear  838  is rotated in the clockwise direction by the shearing motor  842 , the annular member  832  remains stationary relative to the spur gear  838 . As spur gear  838  rotates, the links pull the iris fingers  834  open to release the grip on the shearing cap so the empty pod can be removed from the machine. The iris fingers  834  include a rubber insert  844  that contacts the shearing cap  350  to increase the frictional grip on the shearing cap  350 . The shearing motor  842  is not shown in  FIGS.  43 A and  43 D  for clarity. 
     Some annular members have protrusions that engage recesses of the shearing cap instead of recesses that receive drive lugs of the shearing cap. For example, some annular members include four radially inward extending protrusions or axially extending protrusions. Some annular members include protrusions as part of a self-seating system as described with reference to  FIGS.  45 A- 50 B . 
       FIGS.  44 A- 44 E  are plan and perspective views of a drive mechanism  860  for the machine  100 . The drive mechanism  860  includes an annular member  861  with four drive features  862  (e.g., radially-inward extending protrusions) that engage with drive lugs of a shearing cap. In this example, the pod  200  includes shearing cap  350 , but other shearing caps can be used with drive mechanism  860 . 
       FIG.  44 A  is an isometric bottom view of the drive mechanism  860  with the shearing cap  350  in position within the drive mechanism  860 .  FIG.  44 B  is an isometric top view of the drive mechanism  860 .  FIG.  44 C  is an isometric bottom view of the drive mechanism  860 .  FIG.  44 D  is a top view of the drive mechanism  860  showing a shearing cap  350  in place.  FIG.  44 E  is the same view as shown in  FIG.  44 A  except a shearing cap is not shown. 
     The drive mechanism  860  includes drive features  862  located on an inner diameter surface of the annular member  861  that rotationally engage corresponding drive lugs  356  of cap  350  (or walls of recesses of cap  760 , for example). In this example, the drive mechanism  860  includes four equally spaced drive features  862  that engage a respective number of drive lugs  356 . Each of the four drive features  862  span a small (e.g., less than 20 degree) portion of the circumference around the annular member  861  to reduce the chances of the drive lugs  356  landing directly on top of the drive features  862 . Other drive mechanisms include more than four drive feature (e.g., 5-10) and other drive mechanisms includes less than four drive features (e.g., 1-3). 
     As a user inserts a pod with a shearing cap into the machine  100 , the pod slides through the opening of the evaporator  154  with a first amount of friction between the sidewall of the pod and the sidewall of the evaporator  154 . In some examples, this first amount of friction is caused by the close proximity of the sidewall of the pod and the sidewall of the evaporator  154 . In some examples, this close proximity is a gap of between 0.01″ and 0.035.″ In some examples, this close proximity is a gap of between 0.005″ and 0.05.″ 
     After the user inserts the pod into the opening of the evaporator, the machine  100  controls the shearing motor  866  to cause the drive features  862  to rotate in a clockwise direction  864  (e.g., via one or more gears). The drive features  862  rotate with respect to the pod because the sidewall of the pod is frictionally engaged with the sidewall of the evaporator (e.g., by the first amount of friction). The first amount of friction is sufficient to restrict a rotation of the pod while the shearing motor  866  rotates the drive features  862  underneath the drive lugs  356 . For example, if a user inserts the pod so that the drive lugs  356  land directly on top of the drive features  862 , then the machine  100  rotates the shearing motor  866  to rotate the drive features  862  circumferentially away from the drive lugs  356  with the body of the pod stationary (or substantially stationary). Once the drive features  862  are rotated away from the drive lugs  356 , the pod can be completely inserted into the machine  100  by the weight of the product within the pod, by the drive shaft of the machine pushing down on the pod (e.g., via engagement with the drive head of the mixing paddle), or, by the user. In the completely inserted position, the drive lugs  356  are located in the same plane as the drive features  862 . 
     In some examples, the weight of the product inside the pod provides sufficient force to overcome the first amount of friction and allow the pod to slide through the opening of the evaporator without needing to be pressed into the machine  100  by the user. In some examples, the user can press the pod into the opening of the evaporator to overcome the first amount of friction and assist the pod into the machine  100 . In some examples, the user must press the pod into the opening of the evaporator to overcome the first amount of friction. 
     In some examples, the pod drops into the completely inserted position automatically (e.g., under the weight of the product within the pod without user assistance), and the drive lugs  356  are appropriately located in the same plane as the drive features  862 . In some examples, a user inserts the pod into the machine  100  and, even if the drive lugs  356  land directly on top of the drive features  862 , the machine  100  controls the drive features  862  to rotate away from the drive lugs  356  and then the pod automatically drops into the fully inserted position. This process allows the user to insert the pod into the evaporator of the machine in any angular orientation (e.g., without regard to whether the shearing cap drive lugs  356  or walls of the recesses of cap  760  are in the proper seated position with respect to the drive features  862 ) and without additional user intervention. In some cases, the substantial lack of friction between the drive lugs  356  and the drive features  862  can be advantageous to ensure the pod does not rotate with respect to the evaporator  154  during this process. 
     Once the pod has been completely inserted into the machine  100 , the machine  100  continues to control the shearing motor  866  to cause the drive features  862  to rotate in the clockwise direction  864  (e.g., using the cap shearing system  830 ). This rotation causes a further rotation of the drive features  862  with respect to the body of the pod so that the drive features  862  engage the drive lugs  356 . In some examples, this amount of rotation is a quarter-turn, a half-turn, and/or a full-turn. In some examples, this amount of rotation can be up to a full-turn, e.g., between 0 and 360 degrees. This rotation causes each of the drive lugs  356  to become circumferentially engaged with the corresponding drive features  862  (e.g., in the position shown in  FIG.  44 A ). In some examples, this rotation continues even after the drive lugs  356  are circumferentially engaged with corresponding drive features  862 . In this case, the shearing cap  350  and the body of the pod both rotate with respect to the evaporator and the first amount of friction is overcome by the rotation of the shearing motor  866 . 
     Prior to (and/or during) the freezing process, the machine  100  controls the evaporator  154  to clamp down on the pod. This clamping improves thermal conductivity between the pod and the evaporator and increases the amount of friction between the pod and the evaporator from the first amount to a second, increased, amount. While the first amount of friction still allows the machine  100  to rotate the pod within the evaporator (as described in the immediately preceding paragraph), the increased amount of friction is sufficient to prevent a rotation of the pod with respect to the evaporator  154  during the protrusion shearing process to remove the protrusion from the base of the pod to form an aperture to dispense the cooled food or drink. 
     The machine  100  performs the protrusion shearing process during dispensing. In particular, the machine  100  controls the shearing motor  866  to rotate the drive features  862  further. This further rotation causes the shearing cap  350  to rotate with respect to the body of the pod because the body of the pod is rotationally constrained within the evaporator by the second amount of friction. This rotation of the shearing cap  350  with respect to the pod causes the protrusion of the pod to ride along the ramp shearing features of the shearing cap  350 . This action serves to cut off the protrusion from the base of the pod and open an aperture for dispensing the product from the pod. 
     The shearing motor  866  can apply up to 1,000 ozf-inches of torque to lift and shear off the protrusion of the pod. In some machines, the shearing motor  866  slows down during the protrusion shearing process, and then speeds up during the dispensing process. In this case, it is advantageous for the driveshaft to rotate without stopping or reversing through the mixing, shearing, and dispensing cycle in order to reduce the likelihood of the shearing motor  866  stalling. 
     Some pods have a dispensing mechanism that includes a pop top that can be engaged and released by the machine. When the refrigeration cycle is complete, an arm of the machine engages and lifts a tab of the pod, thereby pressing and puncturing the base and creating an aperture in the base. Chilled or frozen product is dispensed through the aperture. The punctured surface of the base remains hinged to base and is retained inside the pod during dispensing. The mixing avoids or rotates over the punctured surface so that the mixing paddle continues to rotate without obstruction. In some pop tops, the arm of the machine separates the punctured surface from the base. 
       FIGS.  45 A- 45 C  are views of a pod  200  with a self-seating cap  900  attached to an end of the pod  200 . The self-seating cap  900  includes a body  902  with a plurality of recesses  904  arranged circumferentially around the body  902 . Cap  900  is substantially similar to cap  760 . 
       FIGS.  46 A and  46 B  are views of an annular member  912  for the machine  100  with drive features  914  (e.g., guide pins) that are received within the recesses  904  of the self-seating cap  900  to seat the pod  200  within the machine  100  and rotationally couple the self-seating cap  900  to the machine  100 . In some examples, the self-seating cap design significantly reduces the chances of the pod  200  being inserted with the top surfaces  905  of the drive lugs of the caps being located gingerly on the drive features  914  of the annular member  912 . It also reduces the chances of requiring a user to intervene to fully seat the pod  200  within the machine  100 . 
     The cap  900  extends over at least part of the base  220  of the pod  200  and is rotatable relative to the base  220 . The cap  900  has a plurality of axially extending protrusions  906  defining the plurality of recesses  904 . The cap  900  includes a circumferentially extending wall  918 . In some examples, the axially extending protrusions  906  are also defined by a plurality of radially extending walls  906  that extend radially outward from the circumferentially extending wall  918 . The circumferentially extending wall  918  and the plurality of radially extending walls  906  further define the plurality of recesses  904  of the self-seating cap  900 . 
     The axially extending protrusions  906  have a thickness that varies along an axial direction of the pod  200 . The axially extending protrusions  906  have curved surfaces  908  that face into the plurality of recesses  904  of the cap  900 . The axially extending protrusions  906  have a height (along the axial direction) that varies along a circumferential direction due to one or more radiussed or bevelled surfaces of the axially extending protrusions  906 . The axial extending protrusions  906  are characterized by radiussed or bevelled sidewalls when projected in a radial direction. The height of the axially extending protrusions  906  varies along a radial direction. For example, the top surfaces  905  (“tops”) of the axially extending protrusions  906  are tapered such that the height is larger toward the center of the pod  200  and decreases in the outward radial direction. 
     Thickness of the top surfaces  905  of the axially extending protrusions  906  is less than spacing between the respective top surfaces  905  of the axially extending protrusions  906 . An axially-projected surface area of the recesses  904  is greater than an axially-projected surface area of the axially extending protrusions  906 . Each axially extending protrusion  906  has substantially the same profile when projected in a radial direction. The spacing between the each respective axially extending protrusion  906  is substantially the same. The recesses  904  of the cap  900  are substantially the same shape and size. 
     The cap  900  has an aperture  915  (or opening) that extends axially through the cap  900 . The opening  915  is located centrally on the cap  900  and radially inward of the axially extending protrusions  906 . The opening  915  is at least partially defined by an interior radial surface of the circumferentially extending wall  918 . The cap  900  includes an insert  916  located within the opening  915  and attached to the body  902  of the cap  900 . In some examples, the insert  916  is substantially the same as insert  764  of cap  760 . In some examples, the cap  900  further includes the cover  766  of cap  760 . The protrusion  222  of the base  220  of the pod  200  is located in its home position within the aperture of the insert  916 . 
     In some examples, the body  902  of the cap  900  is formed of plastic (e.g., injection molded plastic) and the insert  916  is formed of metal (e.g., aluminum). In other examples, the body  902  and the insert  916  are both formed of metal (e.g., aluminum). 
       FIG.  47    is a cross-section view of the pod  200  with the cap  900  fully seated in the machine  100 . The annular member  912  is rotatable relative to a longitudinal axis of the pod  200  when the pod  200  is received in the recess of the machine  100 . For example, the annular member  912  is rotatable via the cap shearing system  830  or the drive mechanism  860 . 
     The annular member  912  includes a plurality of radially-extending pins  914  sized and shaped to be inserted into at least a subset of the recesses  904  of the cap  900  when the pod  200  is received in the recess of the evaporator  154  of the machine  100  to rotationally couple the cap  900  to the annular member  912 . Each radially-extending pin  914  extends in a radially inward direction from an inner cylindrical surface  920  of the annular member  912 . Each radially-extending pin  914  has at least one angled surface  922 . In some examples, each angled surface  922  contacts at least a subset of axially extending protrusions  906  to cause the cap  900  to rotate relative to the annular member  912  as the pod  200  is received in the recess of the evaporator  154  of the machine  100 . 
     The annular member  912  includes four equally spaced radially-extending pins  914 . In some examples, other annular members include more than four pins (e.g., 5-20 pins). In some cases, other annular members include less than four pins (e.g., 2 or 3). However, four pins  914  strike a good balance between being able to transmit the torque evenly to the cap and design complexity. In some cases, decreasing the number of pins also decreases the probability that the cap might sit on top of the pins such that the cap (and pod) wouldn&#39;t seat itself into place. 
       FIGS.  48 A- 48 C  are views of a prototype machine  100  and a pod  200  for use with the self-seating system. Some machines control a motor (e.g., shearing motors  842  or  866 ) to rotate the annular member  912  to assist in receiving the radially-extending pins  914  within at least the subset of the recesses  904  of the cap  900 . For example, in the off chance that the surfaces  905  of the axial extending protrusions  906  land gingerly on the radially-extending pins  914 , the machine  100  rotates the annular member  912  to cause the recesses  904  to align with the pins  914  so the pod  200  can be automatically seated in the machine  100  (e.g., under the weight of the contents of the pod without additional user assistance). In some examples, the alignment approach described with reference to the drive mechanism  860  is also used with the self-seating pod system. 
       FIGS.  48 B and  48 C  are views from the bottom of the annular member  912 . In  FIG.  48 B , the cap  900  is fully seated in the machine  100 . Four radially-extending pins  914  are received in four of the sixteen recesses  904  of the cap  900 . The radially-extending pins  914  are pentagon-shaped (e.g., have five sides). Some machines have other shaped pins. For example, some machines have a triangular-shaped pin, a diamond-shaped pin, a square-shaped pin, elliptical-shaped pins, or cylindrical pins. The pins  914  are integrally formed with the annular member  912  and cannot move relative to the annular member  912 . 
       FIG.  49    is a perspective view of a prototype machine and pod for use with the self-seating system. The machine includes an annular member  940  with cylindrical pins  942  instead of pentagon-shaped pins  914 . Each cylindrical pin  942  is rotatable along a respective longitudinal axis of the cylindrical pin  942 . Four radially-extending pins  942  are substantially equally spaced around the circumference of the annular member  940 . Each radially-extending pin has at least one curved surface. 
       FIGS.  50 A and  50 B  are perspective views of a pod  200  with a prototype cap  950  installed on an end of the pod  200 . The cap  950  includes a cap body  952  (shear tray), an insert  954  (shear drive), and a cover  956 .  FIG.  50 A  shows the cap  950  with the cover  956  removed to show the protrusion  222  of the pod  200  and the ramp features  958  of the aperture that engages the protrusion  222  to remove the protrusion  222 .  FIG.  50 B  shows the cap  950  with the cover  956  installed to show that the protrusion  222  of the pod  200  and aperture with the ramped surfaces  958  are hidden from view. The cover  956  has an aperture  962  that aligns with the dispensing port  964 . 
     Methods for using the self-seating system include one or more of the following features. A user inserts a pod  200  into a recess of the machine  100 . In some examples, this recess is defined by the evaporator  154  of the refrigeration system of the machine  100 . In some examples, the pod contains ingredients for producing a single serving of a cooled food or drink. 
     The pod includes a cap  900  attached to a base of the pod  200  and rotatable relative to the base of the pod  200 . In some cases, inserting the pod  200  into the recess of the machine  100  causes a plurality of radially-extending pins  922  of an annular member  912  of the machine to contact at least a subset of the plurality of recesses  904  in the cap  900  to seat the pod  200  into the machine  100  and rotationally couple the cap  900  to the annular member  912 . In some examples, seating the pod  200  into the machine  100  is performed without user assistance. In some examples, inserting the pod  200  into the recess of the machine  100  includes contacting the plurality of the radially-extending pins  914  with at least a subset of top surfaces  905  of the plurality of axially-extending protrusions  906  of the cap  900 . 
     In some examples, after contacting the plurality of radially-extending pins  914  with at least the subset of the tops  905  of the plurality of axially-extending protrusions  906 , the machine  100  rotates the cap  900  relative to the annular member  912  without user assistance. In some examples, inserting the pod  200  into the recess of the machine  100  includes contacting bottom surfaces  907  of the subset of the plurality of recesses  904  of the cap  900  with the plurality of radially-extending pins  914 . In some examples, after contacting the plurality of radially-extending pins  914  with at least the subset of the tops  905  of the plurality of axially-extending protrusions  906 , the profiles of the tops  905  of the plurality of axially-extending protrusions  906  and/or the weight of the product within the pod causes the bottom surfaces  907  of the subset of the plurality of recesses  904  of the cap  900  to contact the plurality of radially-extending pins  914 . 
     Some machines rotate an insert  916  of the cap  900  relative to a base of the pod  200  to form or expose an opening in the base of the pod  200 . In some examples, rotating the insert  916  of the cap  900  relative to the base of the pod  200  includes moving a dispensing port  927  of the insert  916  relative to the base of the pod  200 . For example, the machine controls the shearing motor to rotate the cap  900  which rotates the insert  916  relative to the base of the pod  200 . Some machines dispense the produced single serving of the cooled food or drink through the opening of the base of the pod  200  and the dispensing port  927  of the insert  916  of the cap  900 . 
       FIGS.  51 A- 51 C  are perspective views of a mixing paddle  1000  for a pod  200 . The mixing paddle  1000  is concentrically positioned within the pod  200  (the pod is not shown in  FIGS.  41 A- 51 C ). The mixing paddle  1000  is molded or otherwise formed into a structure with hourglass openings  1002 . 
     In some examples, the hourglass pattern allows/facilitates stamping the geometry of the mixing paddle  1000  without the body of the mixing paddle buckling. In some examples, mixing paddle  1000  is formed in a sequential stamping operation. Mixing paddle  1000  is formed such that the helical structure has a constant pitch. In some examples, the constant pitch between 40 and 60 degrees/in (e.g., 52 degrees/inch). Some mixing paddles have varying pitch. The mixing paddle  1000  is stamped with hourglass cutout openings  1002 . The hourglass cutouts  1002  provide rigidity and prevent the structure from buckling during stamping. Some mixing paddles have different numbers and spatial distributions of the cutouts  1002 . These paddles can also be formed with the cutouts of different shapes, for example, like the mixing paddles described in filed Mar. 19, 2020, both of which are incorporated herein by reference in their entirety. In some cases, side ribs  1004  are added for rigidity. 
     The mixing paddle  1000  is attached to a drive head  1006  that includes a keyed female receptacle  1008  for receiving a drive shaft of the machine and rotationally coupling a drive motor of the machine to the mixing paddle  1000 . The mixing paddle  1000  is attached to the drive head  1006  via two axially-extending tabs  1010  by bending the sheet metal on the end of a mixing paddle  1000 . The tabs  1010  are integrally formed with the body of the mixing paddle  1000  and are bendable. In some cases, the drive head  1006  is integrally formed with the mixing paddle  1000 , i.e., a unibody construction. 
       FIG.  51 C  is a top view of the mixing paddle  1000  without the drive head  1006  attached showing the cross-section  1012  of the mixing paddle  1000 . The cross-section  1012  is perpendicular to a longitudinal axis of the mixing paddle  1000  and has at least one curved, non-linear, or angled section. Mixing paddles with at least one curved, non-linear, or angled section provide multiple advantages over a mixing paddle that does not include at least one curved, non-linear, or angled section. In some examples, the resiliency provided by a curved, non-linear, or angled section allows the mixing paddle to maintain direct contact with the inner surface of the sidewall of the pod as the mixing paddle  1000  rotates within the pod. This improves mixing of the ingredients while the machine  100  produces the frozen confection. In some examples, the cross-section has a larger bending, torsional, and flexural stiffness that reduces the flexing of the mixing paddle  1000  during the mixing cycle. For example, as the ingredients cool they become more viscous. This increased viscosity combined with high rotational rates of the mixing paddle (e.g., over 200 RPM) can cause significant forces and stress on the mixing paddle. The outer edges of the mixing paddle in particular bear the brunt of the high stresses where the linear velocity of the mixing paddle is the largest. A cross-section with at least one curved, non-linear, or angled section provides increased stiffness to counter this effect and reduce deflection at the outer edges of the mixing paddle. 
       FIGS.  52 A- 52 C  are perspective views of a mixing paddle  1030  with circular cutouts  1032 , a circular region  1034  for engaging a drive head, and a cross-section  1036  with a non-linear shape. Mixing paddle  1030  is substantially similar to mixing paddle  250  shown in  FIG.  2   . The cross-section  1036  is taken perpendicular to a longitudinal axis of the mixing paddle  1030 . At least a portion of the cross-section  1036  is curved, non-linear, angled, wavy, periodic, and/or undulating. In particular, the cross-section  1036  defines an “S” shape that spans the entire cross-section  1036  (e.g., from a first end  1042 A to an opposite second end  1042 B). In some examples, “S”-shape means that a mid-plane of the cross-section rotates through an “S” pattern as the mid-plane transverses from the first end  1042 A to the second end  1042 B. In some examples, a portion of the S″-shape is a “C”-shape. For example, regions  1038 A and  1038 B are both “C”-shaped. The mixing paddle  1030  exhibits cyclic symmetry about the longitudinal axis. 
     The cross-section  1036  includes a pair of convex features  1038 A,  1038 B each spaced approximately equidistant from the longitudinal axis of the mixing paddle  1030 . The convex features  1038  are convex with respect to a rotational direction  1040  of the mixing paddle  1030 . The rotational direction  1040  is the particular rotational direction used to mix the ingredients disposed within the interior of the pod to produce the single serving of the cooled food or drink. The convex features  1038 A,  1038 B span a majority of the cross-section of the mixing paddle (e.g., greater than 50% of the entire span of the cross-section). The convex features  1038 A,  1038 B are “C”-shaped. The ends  1042 A,  1042 B of the cross-section  1036  are the ends of the convex features  1038 A,  1038 B and contact the inner surface of the pod (the inner surface of the pod sidewall is schematically shown by circle  1064 ). 
     The mixing paddle  1030  includes two perpendicular surfaces (or “shoes”)  1033  that ride along the inside surface of the base of a pod (e.g., the base  220  of pod  200 ). The perpendicular surfaces  1033  function like a plow to scoop ingredients (e.g., free, stuck, or frozen ingredients) that are located on the base  220  of the pod  200  to aid in producing a uniform single serving of a cooled food or drink. Further details about the perpendicular surfaces  1033  are described with reference to  FIGS.  56 A and  56 B . 
       FIGS.  53 A- 53 E  are perspective views of a mixing paddle  1070  with tear-drop-sized cutouts  1072 , a flanged region  1074  for engaging a drive head, and a cross-section  1076  with a non-linear shape. The distinct shape of mixing paddle  1070  is different from mixing paddle  1030 . During testing, mixing paddle  1070  accounted for a 20-30 second reduction in freeze time compared to mixing paddle  1030 . This reduction in freeze time is attributed to the mixing paddle  1070  having a concave shape  1082 A,  1082 B in the direction of travel, rather than a convex shape as described with reference to the mixing paddle  1030 . The convex shape of mixing paddle  1030  allows mixing paddle  1030  to flex backwards and not apply as much pressure to the sidewall of the pod. The concave shape of mixing paddle  1070  keeps the edges  1080 A,  1080 B of the mixing paddle  1030  pressed up against the sidewall of the pod and allows the mixing paddle  1070  to “scoop” the ingredients within the pod. 
     The mixing paddle  1070  includes a curved edge profile  1078  at the pod sidewall (the inner surface of the pod sidewall is schematically represented by the circle  1081 ) providing a larger contact area with the inner surface of the pod. The curved edge profile  1078  allows for more ice to be scraped/removed from the pod sidewall than mixing paddle designs without a curved edge profile  1078 . The curved edge profile  1078  allows the mixing paddle  1070  to be used with various pod geometries (e.g., diameter variations, shape variations, etc.). 
     The mixing paddle  1070  is concentrically disposed within the interior of the pod such that the longitudinal axis of the body of the pod is coincident with the longitudinal axis of the mixing paddle  1070 . The cross-section  1076  is taken perpendicular to a longitudinal axis of the mixing paddle  1070 . Like the mixing paddle  1030 , at least a portion of the cross-section  1076  is curved, non-linear, wavy, periodic, and/or undulating. In particular, the cross-section  1076  defines an “S” shape that spans the entire cross-section  1076  (e.g., from a first end  1080 A to an opposite second end  1080 B). In some examples, a portion of the S″-shape is a “C”-shape. For example, regions  1082 A and  1082 B are both “C”-shaped (or “scoop-shaped”). The mixing paddle  1070  exhibits cyclic symmetry about the longitudinal axis. 
     The cross-section  1076  includes a pair of concave features  1082 A,  1082 B each spaced approximately equidistant from the longitudinal axis of the mixing paddle  1070 . The concave features  1082 A,  1082 B are concave with respect to a rotational direction  1084  of the mixing paddle  1070  used for mixing the ingredients to produce a serving of the cooled food or drink. For example, the machine rotates the mixing paddle  1070  in the rotational direction  1084  to mix the ingredients while cooling the pod to produce the cooled food or drink. The concave features  1082 A,  1082 B span a majority of the length of the cross-section  1076 . 
     A radius-to-thickness ratio of the concave (or convex) features is defined by the expression: 
     
       
         
           
             N 
             = 
             
               r 
               t 
             
           
         
       
     
     where N is the radius-to-thickness ratio; r is the radius of the concave features  1082 A,  1082 B (or the convex features  1038 A,  1038 B of mixing paddle  1030 ); and t is the thickness the cross-section  1076 . Some mixing paddles have a radius r between 0.6 and 1.2 inches, some have a radius r between 0.8 and 1.0 inches, and some have a radius r of 0.90 inches. Some mixing paddles have a thickness t between 0.1 and 0.4 inches, some mixing paddles have a thickness t between 0.1 and 0.3 inches, and some mixing paddles have a thickness t of 0.16 or 0.22 inches. 
     Some mixing paddles have a radius-to-thickness N value between 1 and 10, some have a radius-to-thickness N value between 3 and 6, and some have a radius-to-thickness N value of 4.09 or 5.26. For example, with a thickness of 0.22, mixing paddle  1070  has concave features  1082 A,  1082 B that have a radius-to-thickness N value of 4.09. With a thickness of 0.16, a similar mixing paddle would have concave features with a radius-to-thickness N value of 5.26. 
     The cross-section  1076  has two radial end portions  1090  (shown in  FIG.  53 D ) that are curved in an opposite direction relative to the concave features  1082 A,  1082 B. The first end  1080 A has a radial end portion  1090  that is curved in an opposite direction relative to the concave feature  1082 A and the second end  1080 B has a radial end portion  1090  that is curved in an opposite direction relative to the concave feature  1082 B. The two radial end portions  1090  contact the sidewall of the body of the pod at one or more rotational positions of the mixing paddle  1070  within the pod. For example, the two radial end portions  1090  continuously contact the sidewall of the body of the pod as the mixing paddle  1070  revolves 360 degrees relative to the sidewall of the pod. At least a portion of each of the two radial end portions  1090  is tangent to the inner surface of the sidewall of the pod at the one or more rotational positions of the mixing paddle within the pod. For example, at least portion  1092  is tangent to the sidewall of the pod at all rotational positions of the mixing paddle  1070  within the pod. 
     The mixing paddle  1070  has one or more windows  1072  passing through it. The mixing paddle  1070  has two windows horizontally (radially or side-by-side along the plane of the cross-section  1076 ) and a plurality of windows  1072  arranged vertically (along the axis of the mixing paddle  1070 ). The windows  1072  have mirror symmetry about the longitudinal axis of the mixing paddle  1070 . The windows  1072  are tear-drop shaped but could be other shapes as well (e.g., circular, rectangular, etc.). 
     The mixing paddle  1070  is longitudinally helical along the longitudinal axis of the mixing paddle  1070 . Some mixing paddles have a constant helical pitch between 40 and 60 degrees/inch. Some mixing paddles have a constant helical pitch of 52 degrees/inch. Some mixing paddles have a varying pitch that varies with axial position. 
     The mixing paddle  1070  and the sidewall of the pod are formed of a metallic alloy (e.g., aluminum). The mixing paddle  1070  is coated (e.g., electrostatically coated). The sidewall of some pods are coated with a layer of coating and the mixing paddle  1070  is sized to contact the layer of coating for one or more rotational positions of the mixing paddle  1070  within the pod. In some examples, the layer of coating is a layer of PET laminated coating. The layer of coating is sized such that the coating does not rub off during the cooling and mixing cycle of the pod. For example, tests have shown that the rounded edge profile  1090  reduces damage to the coating on the inside surface of the pod, improving the enamel rating (ER). 
     The drive shaft  122  of the machine  100  (as shown in  FIGS.  6 A- 7 B ) lowers into a keyed recess of the drive head of the pod to rotationally couple a mixing motor to the mixing paddle  1070 . The machine controls the mixing motor to spin the mixing paddle  1070  in rotational direction  1084  such that edges of the mixing paddle  1070  scrape an inner surface of the pod to remove built-up frozen ingredients located on the inner surface of the pod. The machine controls the mixing motor to rotate the mixing paddle  1070  to force the ingredients in an axial direction of the pod and through at least two windows  1072  of the mixing paddle  1070 . The machine controls the mixing motor to rotate the mixing paddle  1070  to force the produced single serving of the cooled food or drink out of the pod after the pod is opened as part of the dispensing process. 
     Some mixing paddles include ribs or other features to increase torsional resistance. Some mixing paddles exhibit high torsional rigidity (e.g., greater than 15 ozf-in) and a high torque to failure limit (e.g., greater than 150 ozf-in). Some mixing paddles have a low surface roughness (e.g., less than 8-16 Ra micro-inches) to prevent product from sticking to the mixing paddle and to help remove product that sticks to the mixing paddle. With mixing paddles having a surface roughness between 8-16 Ra micro-inches, these machines evacuate at least 85% of the frozen confection in the pod and usually 95%. Some mixing paddles have a recess at the second end of the mixing paddle, allowing the mixing paddle to be turned to the center axis of the mixing paddle. During manufacturing, the twist of the mixing paddle at the bottom can be very large 100° to 150° which can be a problem for the stamping process which can tear the material of the mixing paddle. A cut notch (not shown) in the center of the bottom of the mixing paddle blades enables the mixing paddle to be formed without tearing the material. 
     Some devices for mixing food or drink include a body having a longitudinal mixing paddle. Some bodies have a cross-section along a direction perpendicular to the longitudinal axis of the body where at least a portion of the cross-section is S-shaped. For example, mixing paddles  1030  and  1070  have “S”-shaped cross-sections. Some bodies have at least two windows passing through the cross-section of the body. For example, mixing paddles  1030  and  1070  have a plurality of windows  1072 . 
     Some bodies are sized and shaped such that, when the device is rotated within the pod while the pod is cooled: (i) edges of the device scrape an inner surface of the pod to remove built-up frozen ingredients located on the inner surface of the pod; (ii) the S-shaped portion of the body forces ingredients in an axial direction in the pod and through the at least two windows; and (iii) the device forces frozen confection out of the pod after the pod is opened. For example, mixing paddles  1030  and  1070  have all of these features. 
       FIG.  53 D  shows a modified version of the mixing paddle  1070  with a more pronounced “hook”-shape at the radial ends. The mixing paddle  1100  is otherwise the same as mixing paddle  1070 . This “hook”-shape is advantageous because it allows the mixing paddle to accommodate larger pod diameter variations due to a “spring-like” behavior. As shown in  FIG.  53 E , the radial ends of the mixing paddle extend beyond the tangent point with the sidewall of the pod and curve back towards the longitudinal axis of the mixing paddle. 
       FIGS.  54 A and  54 B  are perspective views of a prototype mixing paddle  1120  that substantially represents the mixing paddle  1070 .  FIGS.  54 A and  54 B  show the bottom of the mixing paddle  1120 , i.e., the end that would be adjacent to the base of a pod if the mixing paddle  1120  were inserted into the pod. 
     Some mixing paddles are over-molded with a polymer to squeegee frozen ice cream from the inside of the pod. In some examples, the mixing paddle is an aluminum paddle that is formed by stamping and/or is bent/twisted. In some examples, the mixing paddle is cast, forged, or machined. Ribs on the sides, top, and/or bottom of the mixing paddle provide extra stiffness to the thin areas of the mixing paddle. This extra stiffness is important since the thin areas of the mixing paddle are subject to large torques from the drive head during the mixing process and reduces deformation of the aluminum paddle under this applied torque. Some mixing paddles have edge molds that are molded (i.e., poured and cast) in place over each edge of the mixing paddle, respectively. This process is often referred to as “over-molding,” and can create a part with multiple materials. This over-molded edge can assist with squeegeeing the inner surface of the sidewall of the pod. 
     In some cases, dip coating of plastic is used to coat the mixing paddles to prevent them from directly contacting and rotating on a metal lid and/or pod walls. In some cases, a polyolefin coating is used. 
       FIG.  55 A  shows a mixing paddle  1150  with a pair of notches  1152 . Notches  1152  are sized such that they fit over a lip  1154  on the inside of the base  220  of the pod  200 . Although shown on mixing paddle  1150 , other mixing paddles can also include such notches. Once the mixing paddle is axially lowered to engage the lip  1154  (e.g., via a threaded engagement of the drive head of the mixing paddle with the pod  200 ), the mixing paddle  1150  rotates along the lip  1154  to help keep the mixing paddle  1150  concentrically positioned within the pod  200  and to help provide structural support to the mixing paddle  1150 . 
       FIGS.  55 B and  55 C  show a mixing paddle  1170  that is substantially the same as mixing paddle  1150  but the notch has a slightly different design. The notch  1172  has a curved profile and a radius instead of the hard edges and angles of mixing paddle  1150 . 
       FIGS.  56 A and  56 B  are perspective views of a mixing paddle  1200  that includes two perpendicular surfaces (or “shoes”)  1202  that ride along the inside surface of the base of a pod (e.g., the base  220  of pod  200 ). Mixing paddle  1200  is a prototype of mixing paddle  1030  and includes the same features of mixing paddle  1030 . As noted above, the perpendicular surfaces  1202  function like a plow to scoop ingredients (e.g., free, stuck, or frozen ingredients) that are located on the base  220  of the pod  200  to aid in producing a uniform single serving of a cooled food or drink. 
     For example, in machine  100 , the pod  200  is inserted such that the first end  204  of the pod  200  is face down and the ingredients are forced against the base  220  of the pod  200  due to gravity. During a mixing cycle, the machine  100  rotates the mixing paddle  1200  in the direction represented by arrow  1205  such that leading edges  1204  of the perpendicular surfaces  1202  contact the ingredients on the base  220  of the pod  200  and lift the ingredients off the base  220  (e.g., vertically against the force of gravity) to distribute the ingredients within the pod to produce an even mixture. 
     The perpendicular surfaces  1202  are integrally formed with the body of the mixing paddle  1200  and extend perpendicular (or approximately perpendicular) to the longitudinal axis of the mixing paddle  1200 . The mixing paddle  1200  includes two perpendicular surfaces  1202  that are positioned diametrically opposite each other. Notches  1206  are located radially outward of the perpendicular surfaces  1202 . The notches  1206  are substantially the same as notches  1172  described with reference to  FIGS.  55 B and  55 C . For example, the notches  1206  engage the lip  1154  to help maintain concentricity of the mixing paddle  1200  with respect to the sidewall of the pod  200  as it revolves around within the pod  200 . 
       FIGS.  57 A- 57 C  are plan and perspective views of the mixing paddle  1250  of a pod  200  to form a mating drive assembly  1260 . The mixing paddle  1250  is rotationally coupled to the mating drive head  1252  through a mechanical connection  1264  (best seen in  FIG.  57 C ). The connection  1264  is preferably a welded connection, but other connections can be used. In some cases, the connection  1264  is a friction connection that is formed by engaging one or more grooves  1266  of the mating drive head  1252  onto complementary one or more edges of the mixing paddle  1250 . In some cases, the connection  1264  is engaged by rotating the mating drive head  1252  relative to the mixing paddle  1250  90 degrees. In some cases, the connection  1264  is formed during the manufacturing process when the mating drive head  1252  is molded in the assembled position on the mixing paddle  1250  as shown in  FIGS.  57 A- 57 C . In some cases, the connection  1264  is adhered (e.g., glued). In some cases, the mechanical coupling is made with a fastener (e.g., a set screw). 
     A seal member  1254 , which is substantially similar to seal member  1240 , is adhered to the pod so it cannot move. Adhering the seal member  1254  can be performed with glue, rivets, or any process that would hold the seal member  1254  in place. In some cases, a UV curable glue is used. The seal member  1254  is shown on the outer surface of the pod  200 , but in some pods, is on the interior of the pod. In some pods, the seal member  1254  spans the interior of the pod  200  to the exterior of the pod  200 . 
     Exterior threads  1256  on a cylindrical outer surface of the mating drive head  1252  are configured to threadably engage with corresponding internal threads  1258  of the seal member  1254 . During operation, the drive shaft  122  (not shown in  FIGS.  57 A- 57 C ) of the machine  100  lowers into the receptacle  1270  of the mating drive head  1252 . The receptacle  1270  is keyed (best seen in  FIG.  57 B ) so that rotation is between the drive shaft  122  and the mating drive head  1252  is coupled. As the drive shaft  122  begins to rotate, the exterior threads  1256  begin to unscrew from the interior threads of the seal member  1254 . This causes the mating drive head  1252  to lower itself into the pod  200 . This lowering motion causes the mixing paddle  1250  to lower into the pod  200  as well, but the amount of lowering is preferably small by the using a small thread pitch of the threaded connection between the mating drive head  1252  and the seal member  1254 . Once the external threads  1256  of the mating drive head  1252  lowers past the lower edge of the internal threads  1258  of the seal member  1254 , the threaded connection disengages and the mating drive head  1252  (and the mixing paddle  1250 ) can freely spin within the pod  200  and the bottom of the mixing paddle  1250  lowers onto the lip  1253  of the pod  200 . At this point during operation, the mixing paddle  1250  can spin under the control of the mixing motor of the machine  100 . 
     The threaded connection between the exterior threads  1256  and the interior threads  1258  is reversible if the rotation of the mixing motor of the machine  100  is reversed. This allows the machine to reseal the pod  200 . 
     The mating drive head  1252  also includes a cylindrical section  1271  that is configured to center the mating drive head  1252  and the mixing paddle  1250  in the pod  200  after the threaded connection between the exterior threads  1256  and the interior threads  1258  have disengaged. An outer diameter of the cylindrical section  1271  is slightly less than the internal diameter of the interior threads  1258  so that a rotational clearance is allowed but centering of the mixing paddle  1250  in the pod  200  is also possible. 
     The mating drive head  1252  also functions to seal the pod  200 . Before the mating drive head  1252  is lowered into the position shown in  FIG.  57 A , an O-ring (not shown in  FIGS.  57 A- 57 C ) which is located in a groove  1262  is pressed against the inside dome of the pod  200  forming a seal. This seal is complemented by the threaded connection between exterior threads  1256  and the interior threads  1258 . These seals help to seal outside air from getting into the pod  200  so the pod  200  can remain hermetically sealed until it is ready for use in the machine  100 . 
       FIGS.  58 A and  58 B  are cross-sectional views of a mating drive assembly  1300  in its closed position ( FIG.  68 A ) and its open position ( FIG.  58 B ).  FIG.  58 C  is a perspective view of the mating drive assembly  1300 . The mating drive assembly  1300  is substantially similar to mating drive assembly  1260  seen in  FIGS.  58 A- 58 C . However, the mating drive assembly  1300  includes additions to the functionality of seal member  1254 , and additional sealing measures between the mating drive head  1252  and the seal member  1254 . 
     A locking nut  1302  is adhered to the pod  200 . The locking nut  1302  includes one or more vent holes  1304  to allow nitrogen to escape from the pod  200  when the mating drive head  1306  is unthreaded from the locking nut  1302 . As the mating drive head  1252  is lowered into the pod  200 , pressure of the sealed pod may cause the expulsion of nitrogen and ice cream mix between the threaded connection of mating drive head  1252  and seal member  1254 , and onto the machine components. The vent holes  1304  of locking nut  1302  allow controlled release of the initial pressure along the pathway  1308  indicated in  FIG.  58 B , away from the drive shaft  122  of the machine  100 . The locking nut  1302  has a single vent hole about the circumference. Some locking nuts have multiple vent holes (see, e.g.,  FIG.  58 D ). The locking nut may be formed using a cold heading process. 
     An O-ring, located in a groove  1310 , is pressed between mating drive head  1306  and locking nut  1302  forming a seal. This seal complements the venting holes  1304  to help prevent nitrogen and ice-cream mix from escaping pod  200  through the threaded connection of the mating drive head  1252  and seal member  1254  to the drive shaft  122 . Before the mating drive head  1252  is lowered into the position shown in  FIG.  58 B , an O-ring  1312  is pressed against the inside dome of the pod  200  forming a seal. This seal is complemented by the threaded connection between the exterior threads of the mating drive head  1306  and the interior threads of the locking nut  1302 . These seals help to seal outside air from getting into the pod  200  so the pod  200  can remain hermetically sealed until it is ready for use in the machine  100 . These seals also prevent the nitrogen from escaping (and thus maintaining pressurization) before the sealing shaft is unscrewed from the nut. 
     In some machines, alignment and engagement of the drive shaft  122  with the receptacle  1307  of the drive head  1306  is achieved by monitoring the axial position change of the drive shaft  122  simultaneously with the velocity of the drive motor  116  (See  FIG.  5 A ). To accomplish this engagement, the drive shaft  122  is moved axially downward while the drive motor  116  is rotated at a low torque setting at low speed (e.g., between 1-30% of its maximum value and preferably between 5-15% of its maximum value). The machine&#39;s onboard controller (or processor) monitors velocity of the drive motor  116  until the velocity reaches zero (or stalls) for a set amount of time (e.g., for between 0.1-2.0 seconds and preferably between 0.5-1.0 seconds), indicating that the drive splines of the drive shaft  122  have engaged with the receptacle of the drive head  252 . Once engagement is detected, the motors are briefly paused, and then the drive shaft  122  continues to move axially downward slowly (e.g., at 25-50% of the maximum speed) while the machine&#39;s onboard controller (or processor) monitors the change in position of the drive shaft  122  over time, until the position remains unchanged for a set amount of time (e.g., for between 0.1-2.0 seconds and preferably between 0.5-1.0 seconds), indicating that the drive shaft  122  is fully engaged with the receptacle of the drive head  1306 . During this process, the drive motor is oscillated back and forth continuously (e.g., between +/−5-25% of a full rotation, or preferably between +/−5-10% of a full rotation) to ensure that the drive shaft  122  does not become improperly bound to the receptacle of the drive head  1306 . In some examples, this process ensures that the drive shaft  122  seats properly into the receptacle of the drive head  1306 . 
     After achieving full engagement of the drive shaft  122 , drive motor  116  is activated to unscrew the drive head  1306  from the pod  200 . The drive shaft  122  then continues to move axially downward slowly (e.g., at 25-50% of the maximum speed) while the machine&#39;s onboard controller (or processor) monitors the change in position of the drive shaft  122  over time, until the position remains unchanged for a set amount of time (e.g., for between 0.1-2.0 seconds and more preferably between 0.5-1.0 seconds), indicating that the drive shaft  122  has pushed the bottom of the mixing paddle  1309  against base  220  of pod  200  (see  FIG.  55 A ). 
     In some machines, the onboard controller (or processor) determines if a pod  200  is present (or not) by monitoring for engagement of the drive shaft  122  with the receptacle  1307  of the drive head  1306 . If the onboard controller (or processor) determines that the engagement has not occurred before the drive shaft  122  travels half of a pre-determined or pre-calibrated range of motion, or before a certain amount of time has elapsed (e.g., between 2-10 seconds, or preferably between 4-6 seconds) then the onboard controller (or processor) determines that there is no pod present in the machine and the mixing cycle is aborted. Some machines abort the mixing cycle if the engagement has not occurred before the drive shaft  122  travels one-quarter or one-third of a pre-determined or pre-calibrated range of motion. 
       FIG.  59    shows a prototype pod  200  with the mating drive head  1252  and seal member  1254  described in  FIGS.  58 A- 58 D . The prototype pod  200  further includes a foam structure  1330  to diffuse the gas and liquid spray coming from the venting holes  1304 , reducing the possibility of getting liquid onto the machine components. In some cases, the foam  1330  is placed on the outside the pod  200 . In some cases, the foam is placed inside the pod  200 . Some pods use other absorbent or porous materials instead of foam. Alternatively or additionally, a structure with a labyrinth pattern may be inserted to capture or reduce the ejection pressure of the gas/liquid spray and prevent it from getting onto the machine components. In some cases, the foam is a metallic foam (e.g., aluminum foam). 
     The electronic controller (or processor) of the machine  100  is in electronic communication with the drive motor  116 , the plunger motor  124 , the evaporator motor  166 , and shearing motor (e.g., shearing motor  842  or shearing motor  866 ). The processor controls operation of each of these motors. Some machines include torque sensors that monitor the torques provided by the shafts of each of these motors. Some machines include a lid closure sensor to monitor whether the sliding lid  102  is in the closed configuration. The processor of the machine communicates with all of these sensors and motors. The processor is also electrically connected to the user interface  108 . The processor is programmed to execute one or more operations of the machine  100  to produce a single serving of a cooled food or drink from a shelf-stable pod and dispense the produced food or drink in a user&#39;s bowl or cone within a few minutes (e.g., less than 2 or 3 minutes) for consumption. 
     A number of systems and methods have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of this disclosure. For example, although the evaporators have been generally illustrated as being in vertical orientation during use, some machines have evaporators that are oriented horizontally or an angle to gravity during use. Accordingly, other embodiments are within the scope of the following claims.