Patent Publication Number: US-2017367526-A1

Title: Coffee maker with features for rapid and/or multiple extraction processes, and associated systems and methods

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of International Patent Application No. PCT/US16/12910, filed Jan. 11, 2016, which also claims priority to the following pending applications: U.S. patent application Ser. No. 14/594,970, filed Jan. 12, 2015; U.S. Provisional Patent Application No. 62/171,190, filed Jun. 4, 2015; and U.S. Provisional Patent Application No. 62/267,185, filed Dec. 14, 2015, each of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present technology is directed generally to coffee makers that produce coffee via rapid extractions and/or multiple extractions from a single set of grinds, and associated systems and methods. Results can include flavorful coffee that requires fewer grinds to produce. 
     BACKGROUND 
     Coffee has been a commonly-consumed beverage for many years. Over the course of time, many techniques have been developed to brew coffee, with each having its own advantages and disadvantages. For example, siphon coffee brewers were developed in the 1830&#39;s and were known to produce flavorful coffee, with little bitterness. However, the siphon brewers typically required a long extraction process, which made them impractical for busy coffee shops. Percolators were initially developed in the 1800&#39;s, and became popular in the first half of the twentieth century. Percolators also produce flavorful coffee, unless the brewed coffee is left on high heat for too long a period of time, in which case the coffee can acquire a bitter taste. Percolators have largely been replaced with drip coffee makers, which are simple and produce acceptable coffee. Other representative coffee makers include the Aeropress® and Steampunk coffee maker. 
     One drawback associated with the foregoing types of coffee makers is that none adequately combine low cost with high speed and efficient use of coffee beans. Consumer demand for flavorful, non-bitter coffee has increased over the past several decades, while the resources required to grow high quality coffee beans have become more scarce, particularly in view of environmental concerns associated with coffee plantations. Accordingly, there remains a need for coffee makers and associated processes that meet the foregoing objectives of low cost, high speed, and high quality. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially schematic, side elevation view of a system for making coffee, configured in accordance with an embodiment of the present technology. 
         FIG. 2  is a flow diagram illustrating a process for brewing coffee in accordance with an embodiment of the present technology. 
         FIG. 3  illustrates the system of  FIG. 1 , with ground coffee placed in a brew chamber, in accordance with an embodiment of the present technology. 
         FIG. 4  illustrates the system of  FIG. 3 , with water added to the brew chamber in accordance with an embodiment of the present technology. 
         FIG. 5  illustrates the system of  FIG. 4 , with the water and ground coffee agitated in accordance with and embodiment of the present technology. 
         FIG. 6  illustrates the system of  FIG. 5 , with coffee being extracted from the brew chamber to a coffee chamber in accordance with an embodiment of the present technology. 
         FIG. 7  is a partially schematic illustration of the system shown in  FIG. 6  with a second volume of water positioned to undergo a second brewing process and a second extraction process in accordance with an embodiment of the present technology. 
         FIG. 8  is a partially schematic, cross-sectional illustration of a brew chamber having a filter device configured in accordance with an embodiment of the present technology. 
         FIG. 9  is a partially schematic, cross-sectional illustration of a brew chamber configured to be pressurized in accordance with an embodiment of the present technology. 
         FIG. 10  is a schematic illustration of an automated coffee making system configured in accordance with another embodiment of the present technology. 
         FIG. 11  is a partially schematic illustration of a system having a brew chamber that includes a grind basket fitted with a filter that holds the coffee grinds in accordance with another embodiment of the present technology. 
         FIG. 12  is a partially schematic illustration of a representative example of a siphon coffee system that includes a brew chamber forming an upper or top chamber of the system in accordance with another embodiment of the present technology. 
         FIG. 13A  is a diagram that illustrates how components of the system can be inter-connected in accordance with embodiments of the present technology. 
         FIGS. 13B and 13C  are diagrams of representative coffee brewing methods, in accordance with particular embodiments of the present technology. 
         FIG. 14  is a partially schematic illustration of a system having a modified French press arrangement designed to allow for one or more accelerated extractions in accordance with an embodiment of the present technology. 
         FIG. 15  is a partially schematic illustration of the system shown in  FIG. 14  with the modified French press arrangement activated. 
         FIG. 16  is a partially schematic illustration of a system in accordance with an embodiment in which the brewed coffee is restricted from entering the brew chamber until a valve is actuated by a corresponding controller in accordance with another embodiment of the present technology. 
         FIG. 17  illustrates a representative example of a centrifugal system designed to allow for one or more accelerated extractions in accordance with another embodiment of the present technology. 
         FIG. 18  is a partially schematic illustration of a coffee brewing system having a removable brew chamber configured in accordance with an embodiment of the present technology. 
         FIG. 19  is a partially schematic illustration of a coffee chamber configured to operate with a removable brew chamber in accordance with an embodiment of the present technology. 
         FIG. 20  is a partially schematic illustration of a removable brew chamber configured in accordance with an embodiment of the present technology. 
         FIGS. 21-23  illustrate particular features of an embodiment of the brew chamber shown in  FIG. 20 . 
         FIGS. 24-27  illustrate a filter platform configured for use with a removable brew chamber in accordance with an embodiment of the present technology. 
         FIGS. 28A-28D  illustrate channel patterns in the base of a brew chamber, configured in accordance with embodiments of the present technology. 
         FIGS. 29A-29C  illustrate brew chambers having releasable connections configured in accordance with still further embodiments of the present technology. 
         FIG. 30  is a partially schematic illustration of a system for making coffee, configured in accordance with yet a further embodiment of the present technology. 
     
    
    
     DETAILED DESCRIPTION 
     1.0 Overview 
     The present technology is directed generally to coffee makers configured to brew coffee via multiple coffee extractions, and/or accelerated extractions, and associated systems and methods. Such coffee makers can be suitable for residential and/or commercial purposes depending on the particular embodiment. Specific details of several embodiments of the disclosed technology are described below with reference to particular, representative configurations. In other embodiments, the disclosed technology can be practiced in accordance with coffee makers having other configurations. Specific details describing structures or processes that are well-known and often associated with coffee makers, but that may unnecessarily obscure some significant aspects of the presently disclosed technology, are not set forth in the following description for purposes of clarity. Moreover, although the following disclosure sets forth several embodiments of different aspects of the disclosed technology, several other embodiments of the technology can have configurations and/or components different than those described in this section. As such, the present technology may have other embodiments with additional elements, and/or without several of the elements described below with reference to  FIGS. 1-30 . 
     Aspects of the present technology are generally directed to: (a) multiple coffee extractions; (b) accelerated extractions; (c) removable brew chambers; and (d) controllers and methods associated with the foregoing techniques and devices. Each of the foregoing aspects can include several embodiments, which can be combined with embodiments of the remaining aspects in any of a variety of suitable manners. For example, a multiple extraction process generally includes using the same set of coffee grounds to brew multiple quantities of coffee during a corresponding multiplicity of brew cycles. During the brew cycle, a solvent (typically hot water, but cold water can be used for cold brewed coffee) is in liquid communication with the coffee grounds. Typically, fresh water is used for each cycle, but in some embodiments, the process can include re-using brewed coffee from a prior cycle. Typically, one extraction (of the multiple extractions) is completed before the next brew cycle is started. However, in some embodiments, the extraction process for one cycle can overlap with the brewing process for the next. 
     Accelerated extractions can, in several embodiments, be used for one or more of the multiple extractions described above. An accelerated extraction generally refers to an extraction force that is applied to a quantity of brewed coffee at a particular point in time that was not applied just prior to that point in time, in order to extract the brewed coffee from the grinds. Representative techniques include applying pressure (e.g., pneumatic pressure, hydraulic pressure, or mechanical pressure, for example, with a French press) applying a vacuum, using a siphon process, using centrifugal force and/or opening a previously-closed valve to allow brewed coffee to descend under the force of gravity. In at least some embodiments, combinations of the foregoing techniques are used to extract or separate the brewed coffee from the coffee grinds used to form the brewed coffee. 
     The foregoing processes can be controlled to accurately produce and repeat the timing sequences associated with the processes. The processes can be controlled mechanically, for example, with a mechanical clock mechanism that mechanically or electromechanically operates valves, servos, and/or other actuatable elements. In another embodiment, a digital controller (e.g., a computer or computer-based system) directs the processes used to conduct the coffee brewing and extraction methods. For example, the computer or controller can include computer-based, e.g., programmable, instructions that are coupled to electromechanical valves, servos, and/or other actuators. In particular embodiments, the multiple extractions conducted without the aid of an accelerated extraction device are complete, meaning that the results of one brew cycle are completely extracted (or nearly completely extracted) from the bed of grinds before the next brew cycle begins. In another representative embodiment, in which an accelerated extraction device is implemented, one extraction process may be only partially completed before the next brew cycle begins on the same bed of grinds. 
     As noted above, several embodiments of the disclosed technology may take the form of computer-executable instructions, including routines executed by a programmable computer or controller. Those skilled in the relevant art will appreciate that the technology can be practiced on computer or controller systems other than those shown and described below. The technology can be embodied in a special-purpose computer, controller, or data processor that is specifically programmed, configured or constructed to perform one or more of the computer-executable instructions described below. Accordingly, the terms “computer” and “controller” as generally used herein refer to a suitable data processor and can include internet appliances and hand-held devices, including palm-top computers, wearable computers, cellular or mobile phones, multi-processor systems, processor-based or programmable consumer electronics, network computers, mini computers and the like. Information handled by these computers can be presented at any suitable display medium, including a liquid crystal display (LCD). 
     The present technology can also be practiced in distributed environments, where tasks or modules are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules or subroutines may be located in local and remote memory storage devices. Aspects of the technology described below may be stored or distributed on computer-readable media, including, magnetic or optically readable or removable computer discs, as well as distributed electronically over networks. Data structures and transmissions of data particular to aspects of the technology are also encompassed within the scope of the present technology. 
     2.0 Representative Embodiments 
       FIG. 1  is a partially schematic, side elevation view of a coffee making system  100  configured to produce coffee via multiple extractions from the same volume or mass of ground coffee. The system  100  can also produce the coffee via relatively high pressure differentials during a coffee extraction process, in addition to or in lieu of producing the coffee via multiple extractions. Accordingly, as will be described in greater detail below, the system  100  can produce flavorful coffee with less ground coffee than is used by conventional techniques and brew systems, and with little or no bitter taste. 
     As shown in  FIG. 1 , the system  100  can include a brew chamber  110  for brewing coffee, and an extraction or coffee chamber  120  in which the extracted coffee is collected. Ground coffee beans are placed in the brew chamber  110 , as is hot water provided by a boiler  160 . During the brewing process, the hot water and coffee grinds may (optionally) be agitated via an agitation device  170  before the coffee is extracted through a filter device  130  into the coffee chamber  120 . The agitation device  170  can include an aperture  171  through which a pressurized gas (e.g., air) is directed so as to stir or mix the coffee grinds in the brew chamber  110 . The same coffee grinds can be used to brew multiple volumes of extracted coffee, which are collected together in the coffee chamber and dispensed via a coffee outlet  123 . 
     In a particular embodiment, the brew chamber  110  can include one or more side walls  111  (e.g. a continuous circular cylindrical or conical side wall  111 ), and a lower surface  112  (e.g. a sloped or canted lower surface  112 ), and can house the filter device  130 . The boiler  160  can include (or can be coupled to) a water source  161 , and can further include a heat source  162  (for heating the water provided by the water source  161 ), and a water inlet conduit  163  that directs the heated water into the brew chamber  110 . Brewed coffee follows a fluid flow path that passes through the filter device  130 , through a chamber connector  114  (that connects the brew chamber  110  to the coffee chamber  120 ) and into the coffee chamber  120  via an optional flow tube  125 . Accordingly, the fluid flow path joins and includes the brew chamber  110  and the coffee chamber  120 . 
     In a particular embodiment, the filter device  130  encloses an extraction area A 1 . For example, depending upon the volume of water that the brew chamber  110  is configured to handle, the extraction area A 1  can be about 113 in. 2  (corresponding to a round filter device  130  having a diameter of 12 inches). In other embodiments, the extraction area A 1  can be about 20 in. 2  or 38 in. 2  (corresponding to filter devices  130  having diameters of about 5 inches, or 7 inches, respectively). In any of these embodiments, the relatively large area A 1  allows a given volume of coffee grinds to be spread in a relatively thin layer over the filter device  130 . This in turn can increase the speed with which brewed coffee is extracted through the filter device  130 , and/or can reduce the likelihood that extended contact between the brewed coffee and the coffee grinds will produce a bitter-tasting coffee. 
     The system  100  can include a gas port  115  in fluid communication with the coffee chamber  120 . In a particular aspect of this embodiment, the gas port  115  can selectively be coupled to an accelerated extraction device, for example, a pressure differential device  105  that produces a pressure differential between the brew chamber  110  and the coffee chamber  120 . The pressure differential device  105  can include a vacuum source  101  and/or a pressure source  102  coupled to a first valve  141   a.  The vacuum source  101  is configured to draw a significant negative pressure on the coffee chamber  120 , causing the brewed coffee to rapidly pass from the brew chamber  110  through the filter device  130  and into the coffee chamber  120 . Accordingly, the vacuum source  101  is a representative example of a pressure differential device  105  that produces a relatively high pressure differential (e.g., at least 60 torr in some embodiments, and at least 150 torr in further particular embodiments) between the brew chamber  110  and the coffee chamber  120 . In another embodiment, described later with reference to  FIG. 9 , the pressure differential device  105  includes a pressure source coupled to the brew chamber  110  to force the brewed coffee from the brew chamber  110  into the coffee chamber  120 . In either embodiment, the significant pressure differential provided by vacuum and/or by pressure can allow the operator to use finely ground coffee (e.g., having a diameter of from about 200 μ to about 600 μ and in a particular embodiment, about 200 μ) that would otherwise clog typical existing commercially available batch brewers, such as high volume drip coffee brewers. Furthermore, in either embodiment, the gas port  115  can be selectively coupled to a pressure source  102  for purposes in addition to or in lieu of extracting the brewed coffee. For example, the pressure source  102  can agitate the coffee and water in the brew chamber  110  during the brewing process. Accordingly, the pressure source  102  can form a portion of the agitation device  170 , described further below with reference to  FIG. 5 . 
     In a particular embodiment, the coffee chamber  120  can be positioned below the brew chamber  110 , as shown in  FIG. 1 . In other embodiments, the brew chamber  110  and the coffee chamber  120  can have other positions relative to each other, particularly when, as discussed above, pressure or vacuum (rather than gravity) provides the primary force that directs the brewed coffee through the filter device  130  from the brew chamber  110  to the coffee chamber  120 . 
     The coffee chamber  120  can have one or more side walls  121  (e.g. a conical side wall  121 ) and a base  122 . In a particular embodiment, the system  100  is supported on the base  122  and in other embodiments, the system  100  can include other supports. For example, the system  100  can include an outer shell (e.g., a metal case or a plastic case) to provide support for the system  100 . The outer shell can also serve a cosmetic purpose, e.g., by improving the outward appearance of the system  100 . In at least some of these embodiments, the coffee chamber  120  includes the coffee outlet  123  and can further include a second valve  141   b  through which the brewed coffee is directed out of the system  100  after the brewing and extraction processes have been completed. In other embodiments, the coffee chamber  120  can serve as a carafe. Accordingly, the coffee chamber  120  need not include an outlet  123 . Instead, the coffee chamber/carafe  120  can be removed from the system  100  (e.g., by separating it from the brew chamber  110 ) and the coffee can be poured out from the top of the coffee chamber/carafe  120 . 
     In one embodiment, the processes for making coffee using the system  100  can be completed manually, e.g., via mechanical devices. In another embodiment, the system  100  can include a controller  140  for automatically controlling some or all of the processes used to make the coffee. The controller can include hard-wired circuits, and/or can be programmable. For example, the controller  140  can include a processor, memory and suitable input/output facilities. Accordingly, the controller  140  can receive sensor signals  142  (e.g. corresponding to system temperatures, pressures, flow rates and/or other suitable parameters) and can receive user inputs via a user input device  143  (e.g., buttons, a keyboard, touch screen, and/or other suitable device). Based on the received inputs, the system  100  can provide user outputs to a user output device  145  (e.g. a display panel) and it can provide system commands  144 . The system commands  144  can automatically direct (e.g., activate, deactivate and/or modulate) the system components, e.g., the valves  141   a,    141   b,  the boiler  160 , the vacuum source  101  and/or the pressure source  102 . The automated or partly automated processes available via the controller  140  can reduce the operators workload and/or can improve the precision and/or consistency of the brewing and/or extraction processes. 
       FIG. 2  is a flow diagram illustrating a process  200  for brewing coffee in accordance with a particular aspect of the disclosed technology. Individual steps in the process are then described further below with reference to  FIGS. 3-7 . The overall process  200  can include a first phase  220  that in turn includes brewing the coffee, and a second phase  230  that includes extracting brewed coffee from a brew chamber to a coffee chamber. In particular embodiments, each phase is undergone once, and in other embodiments, the first and second phases are repeated once, twice, or more times to produce a single batch of coffee. 
     Prior to the first phase, process portion  201  includes placing ground coffee in a brew chamber. In addition to standard grind sizes used by existing commercially available batch brewers, the coffee can be finely ground, for example, to a median diameter of from about 200 μ to about 600 μ, or about 320 μ to about 400 μ, about 335 μ, or about 200 μ. These diameters are significantly smaller than the 800 μ diameter used in standard drip processes. The coffee can be spread thinly in the brew chamber, e.g. to a depth of less than 0.7 inches, or from about 0.2 inches to about 0.6 inches, or about 0.3 inches to about 0.5 inches, or about 0.4 inches, as measured after brewing. In general, spreading the coffee so as to have a post-brew depth of less than one inch can reduce the likelihood for the resulting coffee to have a bitter taste. On the other hand, spreading the coffee to have a post-brew depth of less than 0.1 inches can produce a brew chamber width or diameter that occupies too much space in a typical commercial setting. 
     During the first phase (process portion  203 ), a volume of heated water is placed in the brew chamber. The water can be heated using a boiler or other suitable device and can enter the chamber from any suitable port or opening. In any of these embodiments, the volume of heated water is placed in intimate thermal and physical contact with the coffee grinds in the brew chamber. Optionally, process portion  205  can include agitating the coffee grinds and the hot water, for example, using a mechanical device and/or an aeration process. 
     The second phase  230  can include process portion  207 , in which a volume of brewed coffee is extracted from the brew chamber into the coffee chamber. In a particular embodiment, a vacuum is applied to the coffee chamber to draw the brewed coffee into the coffee chamber, and in another embodiment, pressure is applied to the brew chamber to drive the brewed coffee into the coffee chamber. In yet another embodiment, pressure is applied to the brew chamber, in combination with vacuum applied to the coffee chamber. In any of these embodiments, the extraction process can be completed after the water in the brew chamber has completed the brew cycle (e.g., to extract flavor from the ground coffee), and can be completed in a short period of time (e.g., to prevent the brewed coffee from being in contact with the coffee grinds for too long, which can cause the coffee to taste bitter). Accordingly, the pressure differential between the brew chamber and the coffee chamber can be less than 60 torr or 150 torr (e.g., zero) during the first phase  220 , and greater than 60 torr or 150 torr during the second phase  230 . For example, the brew chamber can be at atmospheric pressure during the first phase  220 . During the first phase  220 , a small amount of brewed coffee can pass from the brew chamber to the coffee chamber under the force of gravity, but the pressure differential between the chambers will be less than 60 torr. The fineness of the grind used in the process (which can enhance the coffee flavor strength) can also reduce the amount of brewed coffee that may leak from the brew chamber  110  to the coffee chamber  120  during the brew cycle. This in turn improves the controllability and reproducibility of the brew process because all or virtually all of the coffee will spend approximately the same amount of time in the brew chamber. In general, the threshold pressure differential of 150 torr can be advantageous over the threshold value of 60 torr because the higher pressure differential value produces a faster extraction process. 
     In at least some embodiments, the process ends at process portion  207 . Accordingly, the grounds placed in the brew chamber in process portion  201  are used once with a single volume of water to produce a corresponding single volume of coffee. In other embodiments, the same grinds can be used for multiple volumes of coffee. Accordingly, process portion  203 ,  205  (optionally) and  207  can be repeated in series, once, twice, three times or more to produce a combined volume of coffee in the coffee chamber, with the combined volume being formed from individual volumes of coffee, each of which has been brewed with the same set of grinds. 
     In addition to quickly extracting the brewed coffee from the brew chamber into the coffee chamber, the high pressure differential provided by the pressure differential device can dry the grinds in the brew chamber. As a result, the dry grinds can provide a better starting point for the second (and any further subsequent) brew processes. Therefore, the likelihood for the subsequent processes to produce a bitter-tasting coffee can be further reduced. In addition, the strong pressure differential can remove the majority of dissolved gasses from the coffee grinds, which may be trapped in the coffee beans used to produce the grind during the roasting process. As a result, in subsequent extractions following the first extraction, the grinds can have a significantly larger exposed surface area, and the water used during the subsequent extractions can contact the additional surface area, which is no longer blocked by gas. 
       FIGS. 3-7  illustrate several phases of the foregoing process.  FIG. 3  illustrates the system  100  after an amount of coffee grinds  350  has been added to the brew chamber  110 . As discussed above, the coffee grinds  350  can be spread in a relatively thin layer over the large surface area provided by the filter device  130 . 
     In  FIG. 4 , hot water  464  is introduced into the brew chamber  110  so as to be in intimate physical and thermal contact with the coffee grinds  350 . The hot water is introduced from the boiler  160 , and is directed into the brew chamber  110  until a first volume  464   a  of hot water is positioned in the brew chamber  110 . The first volume  464   a  remains in the brew chamber and in contact with the ground coffee  350  until the brewing process with the first volume  464   a  has been completed. 
     As shown in  FIG. 5 , an optional part of the brewing process can include agitating the coffee grinds  350  and the first volume  464   a  of hot water, e.g., via the agitator  170 . In a particular aspect of this embodiment, the pressure source  102  is activated and the first valve  141   a  is configured to allow pressurized air (or another gas) from the pressure source  102  into the brew chamber  110 . Accordingly, the agitator  170  can include an aerator. The pressurized air agitates both the coffee grinds  350  and the first volume  464   a  of hot water. The pressure provided by the pressure source  102  is controlled or modulated to provide adequate agitation without unnecessarily splashing or scattering or over-agitating the coffee grinds  350 , the brewed coffee, and/or the first volume of water  464   a.  Over-agitation can lead to over-extraction during any given extraction process, which can produce bitter-tasting coffee. If the system  100  includes the flow tube  125 , the pressure source  102  can direct coffee that may already be present in the coffee chamber  120  back into the brew chamber  110 , e.g., to supplement the agitation action provided by the air or other gas, and/or to re-introduce already-brewed coffee into the brew chamber. The process of re-introducing already-brewed coffee can be used to modify the level of extracted solids present in the solvent during extraction, offering an additional level of control over the extraction process. The flow tube  125  can also reduce the likelihood for coffee to be aspirated into the vacuum source  101  during the coffee extraction process, which is described in further detail below. 
     Once the brewing process (e.g., the initial brewing process) has been completed (which can take from about 5 seconds to about 5 minutes), the brewed coffee is removed from the brew chamber  110  and directed into the coffee chamber  120 . For example, as shown in  FIG. 6 , the brewed coffee follows a flow path  626  from the brew chamber  110  to the coffee chamber  120  and collects in the coffee chamber  120 , forming a first volume  651   a  of extracted coffee. In order to force the extracted coffee at a high volumetric flow rate from the brew chamber  110  to the coffee chamber  120 , the vacuum source  101  is activated and the first valve  141   a  is adjusted to connect the vacuum source  101  with the coffee chamber  120 . The vacuum source  101  can create a negative pressure in the coffee chamber  120 , e.g., an absolute pressure of from about 0.000000001 (or 10 −9 ) torr to about 700 torr, or about 150 torr to about 660 torr, or about 175 torr to about 400 torr, or about 175 torr. When the brew chamber  110  is at atmospheric pressure, the foregoing absolute pressures correspond to pressure differentials (between the brew chamber  110  and the coffee chamber  120 ) of from about 60 torr to about 759.999999999 torr, or about 100 torr to about 610 torr, or about 360 torr to about 585 torr, or about 585 torr. Accordingly, the pressure differential is at least 60 torr. In other embodiments, the pressure differential can have other threshold values. For example, in certain embodiments, the pressure differential for a single-extraction device is at least 150 torr or about 360 torr to about 585 torr, or about 585 torr. The pressure differential device  105  can have a flow capacity suitable for any of the pressure differentials described above, for example, a flow rate of at least one cubic foot per minute (CFM), e.g., for a period of at least 5 seconds. 
     The pressure differential draws the extracted coffee from the brew chamber  110  to the coffee chamber  120 . Because the gas port  115  is located above the first volume  651   a  of extracted coffee, the extracted coffee that collects in the coffee chamber  120  is not sucked through the gas port  115  by the vacuum source  101 . Representative extraction times of each extraction process can range from about 5 seconds to about 60 seconds, depending on factors that include the pressure differential level, the volume of coffee removed from the brew chamber  110  with each extraction, and the fineness of the coffee grind. 
     In another embodiment, also illustrated in  FIG. 6 , the gas port can have other locations. For example, a gas port  115   a  can be located beneath the filter device  130 , but above the coffee chamber  120 , provided the gas port  115  includes an arrangement for preventing the extracted coffee from being aspirated into the vacuum source  101 . Accordingly, the system  100  can include a shield  127  that prevents aspiration, while allowing the extracted coffee to proceed into the coffee chamber  120  under the force of gravity, after it has been extracted through the filter device  130 . 
     As shown in  FIG. 7 , a second volume of hot water  464   b  has been placed in the brew chamber  110  and the process described above with reference to  FIGS. 5 and 6  is repeated. The result is that a second extracted coffee volume  651   b  is directed through the filter device  130  and into the coffee chamber  120  to mix with the first extracted coffee volume  651   a.  The combined extracted coffee volume  751   c  is then withdrawn from the system via the coffee outlet  123  and the second valve  141   b.    
     With reference now to  FIG. 8 , a representative brew chamber  810  can include a filter device  830  having multiple components. In a particular embodiment of the present technology, for example, the filter device can include a re-usable, perforated filter support  831  that carries a disposable filter element  832 . In a further aspect of this embodiment, the filter device  830  can be fixedly but releasably positioned in the brew chamber  810 , and can include a non-disposable filter. For example, the brew chamber  810  can include an upper portion  816   a  that is removeably coupled to a corresponding lower portion  816   b.  The filter device  830  can be positioned between the upper and lower portions, and can be held in place with a filter clamp  833  that also releasably couples the upper and lower portions  816   a,    816   b  together. The filter support  831 , the filter element  832 , and the filter clamp  833  are configured to withstand a positive or negative pressure applied to the system during the coffee extraction process. The filter element  832  can be formed from any of a number of suitable media, including paper, cloth and/or perforated metal. In a representative embodiment, the filter element  832  is formed from paper, with a pore size of about 5 microns. 
     The brew chamber  810  can further include a lid  817  having one or more retention elements  819  that keep it centered on the upper portion  816   a.  A corresponding water inlet conduit  863  can be built into the lid  817 . In one embodiment, the lid  817  can be held in place with a clamp (similar to the clamp described below with reference to  FIG. 9 ). In other embodiments, the force of the vacuum applied to the brew chamber  810  keeps the lid in place during the extraction process. 
       FIG. 9  illustrates a brew chamber  910  configured in accordance with still another embodiment of the present technology. In one aspect of this embodiment, the upper portion  816   a  of the brew chamber  910  is pressurized, in contrast with the arrangement described above in which the lower portion  816   b  of the brew chamber  910  is subjected to a vacuum. Because the upper portion  816   a  is pressurized, the upper portion  816   a  is coupled to a pressure differential device  905  that includes a pressure source  902 . A chamber lid  817  is releasably connected to the upper portion  816   a  with a removable lid clamp  918 . In particular embodiments, the system includes a pressure release mechanism that releases the pressure in the brew chamber  910  during the brewing process. Accordingly, the elevated pressure in the brew chamber  910  can be provided only during the process of directing post-brew coffee from the brew chamber  910  into an associated coffee chamber. The brew chamber  910  is accordingly sealed during the foregoing extraction process to prevent a pressure leak from the brew chamber  910  that would reduce the efficiency with which the applied pressure extracts the brewed coffee from the brew chamber  910 . In a representative process, the upper portion  816   a  is pressurized to a value up to about two atmospheres (e.g., about 30 psi absolute pressure or 15 psi gage pressure) and in other embodiments, the upper portion  816   a  is pressurized to a value up to about ten atmospheres. In any of these embodiments, the pressure source  902  can provide enough pressure to produce a pressure differential of at least 60 torr between the upper portion  816   a  and the lower portion  816   b  (or the associated coffee chamber). 
     Table 1 below illustrates representative results obtained using an apparatus generally similar to that described above with reference to  FIGS. 1 and 8 . In this embodiment, a total of three extraction processes were performed to produce approximately one liter of brewed coffee. The process was conducted at two different vacuum levels: a first or high vacuum of 176 torr (absolute pressure), and a second or medium vacuum of 659 torr (absolute pressure). At each vacuum level, coffee was produced using three different grind sizes. Grind A corresponds to a fine grind (finer than the standard drip grind of 800 μ), grind B corresponds to an espresso grind (which is finer than grind A) medium grind, and grind C corresponds to an espresso fine grind, e.g., a grind finer than typical espresso grind. The foregoing extraction processes were conducted with a system having a 5-inch diameter brew chamber. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Grind “A” 
                 Grind “B” 
                 Grind “C” 
               
               
                   
                   
               
             
            
               
                   
                 High Vacuum 
                 First Pull:  
                 First Pull:  
                 First Pull:  
               
               
                   
                 (Vac Attained:  
                 15 sec 
                 10 sec 
                 30 sec 
               
               
                   
                 176 torr) 
                 Second Pull:  
                 Second Pull:  
                 Second Pull:  
               
               
                   
                   
                 30 sec 
                 32 sec 
                 40 sec 
               
               
                   
                   
                 Third Pull:  
                 Third Pull:  
                 Third Pull:  
               
               
                   
                   
                 20 sec 
                 42 sec 
                 60 sec 
               
               
                   
                 Med Vacuum 
                 First Pull:  
                 First Pull:  
                 First Pull:  
               
               
                   
                 (Vac Attained :  
                 20 sec 
                 30 sec 
                 35 sec 
               
               
                   
                 659 torr) 
                 Second Pull:  
                 Second Pull:  
                 Second Pull:  
               
               
                   
                   
                 30 sec 
                 45 sec 
                 55 sec 
               
               
                   
                   
                 Third Pull:  
                 Third Pull:  
                 Third Pull:  
               
               
                   
                   
                 30 sec 
                 40 sec 
                 60 sec 
               
               
                   
                   
               
            
           
         
       
     
     Each complete brew was performed using 43 grams of coffee and one liter of water, with a cloth filter. Each first pull or extraction used 400 mL of water, and each second and third pull or extraction was performed with 300 mL of water. The average height of the coffee grinds resting on the filter, after the brew process was complete, was approximately 0.4 inches. An additional set of results was obtained using a paper rather than a cloth filter for grind C. The results included a faster extraction process, with the second and third pulls at 20 seconds each, rather than at 40 and 60 seconds, respectively, for the high vacuum. When the medium vacuum was used, the extraction process was longer, including 40 seconds for the first pull, 70 seconds for the second, and 65 seconds for the third. The times in Table 1 are extraction times only. Corresponding brewing times were 40 seconds per cycle, prior to initiating extraction. 
     Table 2 below illustrates representative results obtained using another apparatus generally similar to that described above with reference to  FIGS. 1 and 8 . In this embodiment, a paper filter was used in place of a cloth filter. In addition, the system included a 7-inch brew chamber, and the pull times were reduced compared to the times shown in Table 1. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                   
                 Grind “A” 
                 Grind “B” 
                 Grind “C” 
               
               
                   
                   
               
             
            
               
                   
                 High Vacuum 
                 First Pull:  
                 First Pull:  
                 First Pull:  
               
               
                   
                 (Vac Attained:  
                  8 sec 
                  8 sec 
                  9 sec 
               
               
                   
                 176 torr) 
                 Second Pull:  
                 Second Pull:  
                 Second Pull:  
               
               
                   
                   
                 12 sec 
                  8 sec 
                  7 sec 
               
               
                   
                   
                 Third Pull:  
                 Third Pull:  
                 Third Pull:  
               
               
                   
                   
                  8 sec 
                 15 sec 
                 18 sec 
               
               
                   
                 Med Vacuum 
                 First Pull:  
                 First Pull:  
                 First Pull:  
               
               
                   
                 (Vac Attained:  
                  5 sec 
                  8 sec 
                 12 sec 
               
               
                   
                 659 torr) 
                 Second Pull:  
                 Second Pull:  
                 Second Pull:  
               
               
                   
                   
                  8 sec 
                  8 sec 
                 15 sec 
               
               
                   
                   
                 Third Pull:  
                 Third Pull:  
                 Third Pull:  
               
               
                   
                   
                 10 sec 
                 15 sec 
                 20 sec 
               
               
                   
                   
               
            
           
         
       
     
     Further, the average height of the coffee grinds resting on the filter, after the brew process was complete, was approximately 0.2 inches. The times in Table 2 (like those in Table 1) are extraction times only. Corresponding brewing times were 40 seconds per cycle, prior to initiating extraction. 
     Each of the foregoing tests produced a flavorful cup of coffee, notably lacking in bitterness. For purposes of comparison, Grind A (the coarsest grind) was also tested in a drip coffee brewer. The process took 7 minutes for 43 grams of grinds and one liter of water, and the coffee produced was markedly bitter. The height of the coffee grinds under these conditions, in a cone filter, was approximately two inches. 
     In at least some embodiments, it is expected that the foregoing times listed in Tables 1 and 2 can vary by ±5 seconds. Accordingly, a pull of 30 seconds can correspond to a range of from about 25 to about 35 seconds. As used herein, the term “about” when used in the context of pull times means within 2 seconds. In general, the term “about” means within 10%, as applied to temperatures, pressures, flow rates, and dimensions. 
       FIG. 10  is a schematic illustration of a system  1000  that is automated in accordance with an embodiment of the present technology. Accordingly, the system  1000  can include a controller  1040  (e.g., a microcontroller) that communicates with several of the system components via signal lines  1046 . The signal lines  1046  can be used to transmit sensed information to the microcontroller  1040  and/or provide instructions from the controller  1040  to the components of the system  1000 . 
     The system  1000  can include a brew chamber  1010  coupled to a coffee chamber  1020  via a chamber valve  1041   b.  Coffee grinds are placed in the brew chamber  1010 . Brewed coffee is extracted through a filter (not visible in  FIG. 10 ), through the chamber valve  1041   b,  through a flow tube  1025 , and into the coffee chamber  1020 . The resulting coffee can be removed from the coffee chamber  1020  via a coffee outlet  1023 . 
     The brew chamber  1010  receives water from a water source  1061 , which is heated in a boiler  1060 , and can be pressurized for flow into the brew chamber  1010  with a water pump  1065 . A flow meter  1066  can be used to measure and/or modulate the flow of water through a corresponding water inlet conduit  1063  into the brew chamber  1010 . The system can include one or more temperature sensors, for example, a temperature sensor  1067  positioned to measure the temperature of the water at the brew chamber  1010 . 
     A pressure differential device  1005  provides vacuum and/or pressure to direct extracted coffee from the brew chamber  1010  into the coffee chamber  1020 . The pressure differential device  1005  can create the required pressure differential via positive and/or negative pressure. One or more optional regulators  1003  and/or pressure differential valves  1041   a  control the introduction of vacuum or pressure provided by the pressure differential device  1005 , and control the communication between the pressure differential device  1005  and the coffee chamber  1020  and/or the brew chamber  1010 . In other embodiments, the regulator(s)  1003  can be eliminated, and instead, the pressure differential device  1005  can have fixed, known vacuum/pressure parameters for controlling the pressure differential between the brew chamber  1010  and the coffee chamber  1020 . In any of these embodiments, the pressure differential device  1005  can include one or more components that apply a vacuum to the coffee chamber  1020  (as shown in solid lines), and/or one or more components that apply pressure to the brew chamber  1010  (as shown in dashed lines). A secondary pump  1004  can be coupled to the coffee chamber  1020 , for example, to provide the agitation force described above with reference to  FIG. 5 . In particular embodiments, an additional regulator can be coupled to the secondary pump  1004  to control the timing and/or pressure provided during the agitation process. 
     A representative process for using the system  1000  described above with reference to  FIG. 10  is described below. 
     Step 1: Program the controller  1040  to set brew parameters (e.g. temperature, water volume per brew/extraction cycle, vacuum/pressure strength and/or start and end times, agitation start and/or end times, and/or agitation strength). An operable combination of parameters is referred to as a “program”. 
     Step 2: Securely fasten a clean filter into the brew chamber  1010 . Depending on the embodiment, this may include placing the filter in the brew chamber  1010 , and securely clamping the filter in place to prevent grinds from passing through or around the corners of the filter during brewing, and to prevent the filter from overly warping if the coffee is agitated during the brew cycle. In representative embodiments, the force provided by the process of clamping the filter in place is higher than is used in conventional processes so as to withstand the higher pressure differential supplied by the pressure differential device  1005 . 
     Step 3: Place a selected weight of ground coffee into the brew chamber  1010 , resting the grind on top of the filter. 
     Step 4: Initiate the program at the controller  1040 . If the controller  1040  includes a touchscreen display, initiating can include pressing a “Start” button. In other embodiments, the start button can include a physical button and/or another suitable interface. 
     Step 5: The controller  1040  directs water from the water source  1061  to the boiler  1060 , where the water is heated to a selected temperature specified in the program (or if water is not provided through a water line, water may be manually placed into boiler, with heating commencing once the water has been placed in the boiler). 
     Step 6: The water reaches the temperature programmed into the controller  1040 . In representative embodiments, the temperature of the water is from about 195° F. to about 205° F. The temperature of the water can be controlled via a feedback device (e.g., a PID controller). In another embodiment, the water is allowed to come to a boil and then rest for pre-specified time to arrive at the programmed temperature. For example, the controller  140  can allow the water to come to a boil, rest for a pre-specified time, and then introduce the water without any specific feedback regarding the temperature of the water. For example, the water can be boiled and then rest for 30 seconds or the water can be heated instantaneously or nearly instantaneously to a programmed temperature, for example, using an induction heater. In at least some of these embodiments, the controller  1040  can direct the boiler  1060  to release a specified volume of heated water, e.g., via a valve. The amount of water can be set by the program. The released water passes into the brew chamber  1010  so as to be in contact with the coffee grinds. The total volume of water released into the brew chamber  1010  may be regulated by the flow meter  1066  placed between the boiler  1060  and the brew chamber  1010 , or the valve can be time-actuated. Without a flow meter present, opening the water valve for a period of time specified in the program means that different water line pressures will lead to different volumes of water being dispensed. Accordingly, the flow meter  1066  can produce a relatively consistent dispensed water volume, despite different water line pressures present in different environments. In a further particular aspect of the foregoing embodiments, coffee within the brew chamber  1010  is prevented from exiting the brew chamber  1010  while the brewing process is underway, and only exits the brew chamber  1010  after a predetermined brewing period. In other words, the coffee does not proceed directly through and out of the brew chamber  1010 , as it does in a typical drip coffee maker. 
     Step 7: The coffee brewing in the brew chamber  1010  is (optionally) exposed to agitation, via an air pump that introduces bubbles, and/or via another agitation mechanism, such as a mechanical stirrer, for an amount of time and at an intensity provided for in the program. 
     Step 8: The brew chamber  1010  is exposed to, acted upon, or subjected to a vacuum and/or an elevated pressure and/or another extraction accelerating force for an amount of time and at a level provided for in the program, evacuating the brew chamber of fluid. In a particular embodiment, nearly all the brewed coffee is evacuated (using a pressure source, vacuum source or both) from the brew chamber, leaving the nearly dry grinds resting on the filter. For example, the grinds can be dried to the point at which only 5-10% of the water initially added to the grinds remains in the grinds after the extraction process. In a representative process, the system shown in  FIG. 10  can be used to obtain 950 mL of coffee from an initial volume of one liter of water. By contrast, one liter of water used in a drip process typically yields only 880-890 mL of brewed coffee. As discussed above, more completely drying the grinds can reduce the likelihood for any remaining water to continue extracting coffee from the coffee grinds. As a result, the process of extracting coffee can be more carefully and precisely controlled, which in turn prevents the process from inadvertently over-extracting coffee from the grinds, which can lead to bitter-tasting coffee. Instead, the drying process can more effectively stop the coffee extraction process, and allow the extraction process to restart at a controlled, selected time, for example, when a subsequent brewing process begins. In addition, increasing the amount of coffee extracted from the coffee grinds can produce more coffee per extraction process, and/or can reduce the amount of coffee grinds needed for a given extraction process or series of processes. In another embodiment, the brewed coffee is not completely evacuated, and is instead only partially evacuated, before the introduction of fresh water into the brew chamber. 
     Step 9: In particular embodiments, e.g., those embodiments that include multiple extractions from a single mass of coffee grinds, Steps 6-8 are repeated at least once, optionally with different parameters for time, vacuum force, water volume and/or other parameters, specified in the program for each repetition. Step 7 may or may not be used during any of the foregoing extraction processes, depending on factors that can include the type of coffee being brewed and/or the desired coffee flavor. 
     Step 10: Once the extraction process has been repeated a suitable number of times, as specified in the program, the brewed coffee that has been evacuated into the coffee chamber is ready for consumption. The coffee may be removed from the coffee chamber via any of a variety of suitable mechanisms, depending on the design of the coffee chamber. For example, coffee can be removed via a spout, or the coffee chamber can be a removable thermal carafe, allowing the user to remove the coffee chamber completely once brewing is complete. The carafe can be used to pour the brewed coffee into a cup. 
     Step 11: Once the entire brewing process is complete, the filter can be removed from the brew chamber, along with the used grounds. Depending on the filter design, the filter may either be cleaned for later use, or disposed of. 
     Step 12: With the filter removed, the brewing device can be cleaned. Cleaning can include manual cleaning using traditional cleaning methods, such as sponge and soap, or can include repeating Steps 4-10 above, without the introduction of coffee grounds. The introduction of heated, agitated water into the system without coffee grounds will have the effect of dissolving residual brewed coffee and eliminating grinds that were not eliminated upon the removal of the filter. 
     One feature of at least some of the foregoing embodiments described above is that a single quantity of brewed coffee can be made by extracting multiple volumes of heated water through the same set of coffee grinds. An advantage of this approach, when compared to conventional approaches, is that the amount of coffee grinds required to produce a cup of flavorful coffee can be reduced significantly. For example, it is expected that the foregoing technique can reduce the required amount of coffee beans by approximately 30% or more, by weight, when compared to conventional drip and/or other coffee making processes. Furthermore, the multiple extraction process allows smaller, more carefully controlled quantities of water to go through the brewing process, which further improves the uniformity of contact between any quantity of water and the coffee grinds. Performing multiple short duration extractions is also less likely to produce bitter coffee than one long-duration extraction, and adding multiple volumes of fresh solvent to the coffee is more likely to extract additional flavor compounds that would otherwise remain unextracted. This result can be based upon a number of factors. For example, bitters (e.g., primarily tannins) are typically extracted from the coffee grinds later in the extraction process. Accordingly, by adding fresh solvent (e.g., water), the brew or extraction process is restarted with each new controlled quantity of solvent added to the grinds. Accordingly, as more of the total brewing/extraction time is spent early in the brewing process for each of the multiple extractions, bitters are less likely to be extracted. By adding a new volume of water for each of the multiple extractions, a new phase partition equilibrium (solid/liquid) begins. In particular, there are no dissolved materials in the newly-added water at the beginning of each new extraction cycle. For each new cycle, the phase partitioning process begins again, with the same compounds partitioning into the new volume of water at set times. Because the bitters are released from the coffee grounds at a generally fixed point in time after the brewing process starts, the brewing process can be deliberately stopped before that point is reached. Furthermore, multiple extraction processes, each using the same set of grinds and a new volume of water, can produce more organic flavor compounds in the resulting coffee. 
     Another feature of at least some of the foregoing embodiments is that a relatively large pressure gradient can be formed between the brewing chamber and the coffee chamber. As discussed above, the pressure gradient can be formed by pressurizing the brewing chamber and/or applying a vacuum to the coffee chamber. A result of the large pressure gradient is that the brewed coffee is quickly extracted from the brewing chamber, therefore allowing more precise control over the amount of time that the brewed coffee is in direct contact with the coffee grinds. This in turn allows the operator to produce flavorful coffee without the coffee becoming bitter as a result of spending excessive time in contact with the coffee grinds. For example, the large pressure gradient can pull a thin layer of water quickly through the filter so that all or a significant portion of the coffee grinds are in contact with water for approximately the same amount of time. By contrast, conventional gravity extraction processes typically are not as amenable to the level of control outlined by the processes described above. It is difficult to brew coffee in conventional manners to produce larger quantities of coffee without a bitter taste. The large pressure gradient can be particularly useful for finer grinds, for which existing methods either are incapable of brewing fast enough to prevent high bitterness levels, or are incapable of producing a brew at all, for example, due to the filter clogging when used with very fine grinds. 
     Still another feature of at least some of the foregoing embodiments is that the brewing chamber and in particular, the filter, can have a large surface area when compared with the volume of coffee grinds that are placed on the filter and/or the volume of coffee produced. The result is that the coffee grinds can form a relatively thin layer of coffee over the filter. This in turn results in a more uniform brew. For example, each portion of hot water passing through the bed of coffee grinds passes through coffee grinds that have been exposed to approximately the same quantity of water. The coffee produced in this manner has a concentration and taste similar to that of drip coffee, without the bitterness associated with other conventional coffee brewing techniques, and is produced in a shorter period of time than typical drip techniques. This is unlike conventional arrangements in which the bed of coffee grinds is relatively deep. In such an arrangement, some water passes through only a portion of the total depth when extraction begins, and other water passes through the entire depth, a problem that is often associated with making espresso, and which is referred to as channeling. Also, for example, utilizing a relatively thin layer of coffee over the filter can improve the controllability and reproducibility of the brew process because all or virtually all of the coffee will spend approximately the same amount of time in the brew chamber. In addition, a thin layer of coffee grinds can significantly accelerate the extraction process by reducing the barrier through which coffee must travel to enter the coffee chamber upon extraction. 
     Still another advantage of the foregoing feature is that the large filter surface area can reduce or eliminate the likelihood for clogging during the extraction process. In particular, the relatively large filter surface area (e.g., in combination with the large pressure differential created by the pressure differential device) can allow the system to brew from finer grinds (e.g., less than approximately 400 microns) without clogging, e.g., because for a fixed weight of grinds, a larger filter surface area will result in a shallower grind bed, and hence create less fluidic resistance to water flowing through the grinds. Finer grinds can typically produce more flavor per unit of extraction time, because they have greater surface area for a given weight of grind and hence organic compounds from the grinds can be extracted more quickly into solvent (e.g. water), but can also produce bitters more quickly. Accordingly, controlling the timing of individual brew cycles can allow the system to consistently and reproducibly produce flavorful, non-bitter coffee. 
     Still another feature of at least some of the foregoing embodiments is that the system can include an active device that applies a vacuum or a positive pressure to the brewing chamber to direct brewed coffee into the coffee chamber. Unlike conventional siphon devices, which typically rely on a small vacuum produced by condensing and/or cooling air and/or water vapor in the coffee chamber, the foregoing arrangement produces significantly higher vacuums and/or pressures, which can expedite the process for withdrawing coffee from the brew chamber, reducing or eliminating the bitterness that can result from the brewed coffee spending too much time in contact with the coffee grounds. 
       FIGS. 11-17  illustrate further representative embodiments of the presently disclosed technology, several of which include at least some of the foregoing features, in addition to or in lieu of further features. 
     A representative process includes placing coffee grinds into the brew chamber by the operator or via an automatic coffee dispensing system, and introducing water via a water introduction device, which is directed by a controller. The coffee is then brewed according to the system&#39;s applicable brew methodology (e.g. drip, siphon, etc.). The resulting brewed coffee is transferred from the brew chamber to a coffee chamber via an applicable methodology (for example, in a drip coffee setup, the coffee drips into the coffee chamber via gravity). Once the coffee has completed or approximately completed brewing and the flow of brewed coffee from the brew chamber to the coffee chamber has completely or approximately stopped as a result, the controller then causes the water introduction device to introduce a second volume of water into the brew chamber, and the applicable brewing process is re-initiated one or more times using the same set of previously-used coffee grinds. The brewed coffee from each such extraction of the same coffee grinds is combined to form the final beverage. 
     The foregoing process can produce one or more significant practical results. For example, by allowing a set of coffee grinds to undergo an entire brew process (e.g., from the introduction of water and subsequent brewing to the flow of brewed coffee from the brew chamber to the coffee chamber, removing all or at least a significant amount of the solvent from the brew chamber), and then adding a fresh volume of water to the same coffee grinds, a new solid-liquid phase partition equilibrium is established by the introduction of the fresh solvent, changing the extraction and, if desired, reducing the total extraction of bitter/astringent compounds. By combining multiple brews made from the same grinds using this method, a given weight of coffee grinds is used to produce a volume of brewed coffee for which the total dissolved solids is comparable to, or greater than, coffee brewed using a substantially greater mass of coffee grinds. 
     In a particular method (conducted, e.g., with an embodiment of the apparatus described above with reference to  FIG. 10 ), a total of 43 grams of ground coffee can be combined with four separate 250 milliliter volumes of water to produce a brewed coffee that has a total dissolved solids of 1300 ppm, which is consistent with the usage of 55-60 grams of ground coffee combined with 1 liter of water using standard drip methodologies. Total dissolved solids (TDS) is a measure of the total content of chemical compounds extracted from the coffee grinds into the water solvent. Higher TDS measurements indicate a greater extent of extraction of chemical compounds into the water. These chemical compounds typically include both compounds that are responsible for the unique flavor of coffee as well as compounds that cause a sensation of bitterness/astringency. Although it is possible to increase the total dissolved solids of coffee brewed with 43 grams of ground coffee using standard drip methodologies to achieve a total dissolved solids typically associated with brewing 55-60 grams of ground coffee through a variety of techniques for increasing extraction, including prolonged extraction or brewing using elevated water temperature, these techniques are typically associated with a dramatic increase in bitterness. Provided that other variables in the coffee brewing process such as extraction time, grind size, temperature, and agitation level are suitably controlled, embodiments of the current method, which establish several solid-liquid phase partition equilibria, increase total dissolved solids of extracted coffee from a given set of grinds while extracting compounds that result in bitterness into the brewed coffee within commercially acceptable ranges, rather than over-extracting bitter compounds (in other words, the coffee is not too bitter to serve to a customer). This is commercially significant, because it allows coffee to be brewed using significantly less ground coffee, by weight (e.g., 20-40% less, in the example provided above, using four extractions of the 250 mL to brew one liter of coffee), while maintaining full flavor and controlling bitterness. 
       FIG. 11  illustrates a system  1100  having a brew chamber  1110  that includes a grind basket  1111  fitted with a paper filter  1112  that holds coffee grinds  1150 . Water is provided by a water pump  1164  which transfers water from a boiler  1160  to a spray head  1165 . The spray head  1165  distributes the water over the coffee grinds  1150 . A corresponding coffee chamber  1120  includes a carafe  1126  or other holding vessel that receives and contains brewed coffee  1151 . The system can include a controller  1140  that directs the pump  1164  to drive a volume of water from the boiler  1160  to the spray head  1165 , then to the grind basket  1111 . The controller  1140  can then wait a pre-programmed, pre-calculated period of time (based, e.g., on the weight of the grinds), after which the water has substantially completed brewing by dripping through the grind basket  1111  and into the carafe  1126 . The controller  1140  can then direct the introduction of a new volume of water into the grind basket  1111  using the previously brewed, non-replaced coffee grinds  1150  and repeat the above steps one or more times. This procedure allows the extraction process to repeat with a fresh volume of solvent. The multiple volumes of brewed coffee are subsequently combined in the carafe  1126 , which can then be emptied by the operator, with the brewed coffee ready for consumption. 
     The foregoing design is distinguished from a conventional pulse brewing drip system or a pre-infusion system, which are other methods that can be used to increase the total dissolved solids of brewed coffee. For example, in the foregoing embodiment, the controller is programmed to specifically wait until the water has substantially completed brewing, whereas in a pulse brewing drip system, water is gradually introduced into the brew chamber in repeated cycles as the coffee is still brewing, and whereas in a drip or espresso pre-infusion system, a volume of water is added to the ground coffee to saturate the grinds with water prior to introducing the majority of the water into the brewing process. The intended effect is also different. Pulse brewing and pre-infusion are designed to saturate the grinds with water, so that they can absorb additional water more readily, and/or to increase the amount of contact time between the water and ground coffee, whereas the embodiment described above is expected to eliminate as much brewed coffee as possible from the coffee grinds by substantially completing the brew process before re-introducing water into the grinds. In other words, pre-infusion and pulse brewing methodologies introduce additional water during the brew process to ensure the grinds are constantly saturated with water, whereas the embodiment described above introduces water into the coffee grounds only once such grounds have substantially completed brewing, hence waiting until the moisture content of such grinds are substantially at their minimum during the brew cycle prior to re-introduction of water. 
     In order to facilitate brew times that are amenable to multiple extractions in the foregoing embodiment without resulting in excess bitterness, an operator can use 20-40% less coffee grounds, by weight, than amounts that would typically be utilized in a commercial setting to brew coffee via a grind basket of a given diameter. By using fewer grinds, water dispensed into a grind basket will substantially complete brewing faster, because the smaller amount of grinds present a lesser barrier for water to drip through, thus reducing the bitterness of each brewed volume of coffee. Although reduced brew times would otherwise translate into a weaker beverage, the foregoing design uses repeated extractions of the same coffee grounds, each at a reduced brew time, to increase flavor extraction. 
       FIG. 12  illustrates a representative example of a siphon coffee system  1200  that includes a brew chamber  1210  forming an upper or top chamber of the system. Coffee grinds  1250  are placed atop a filter  1212  between the brew chamber  1210  and an intermediate brewed coffee storage chamber  1220 , which forms a lower or bottom chamber. A corresponding controller  1240  is programmed with instructions that can: 
     (a) cause a water pump  1264 , operating as a water introduction device, to direct a volume of water from a boiler  1260  into the lower chamber  1220 , 
     (b) then direct the activation of a heating element  1262  acting upon the lower chamber  1220 , causing the water to travel up through a brew tube  1214  into the upper chamber  1210  as a result of water vapor pressure buildup in the lower chamber  1220  caused by the heating of the water therein, 
     (c) then wait a pre-specified time, allowing the coffee to brew sufficiently in the upper chamber  1210 , 
     (d) then direct the heating element  1262  to cool (e.g., by shutting off the heating element), causing the water vapor in the lower chamber  1220  to condense, forming a vacuum that causes the brewed coffee to descend from the upper chamber  1210  to the lower chamber  1220 , via the brew tube  1214 , 
     (e) then cause the descended brewed coffee  1251  to be released from the lower chamber  1220  to the coffee chamber  1290 , by actuating a valve  1291  that creates a flow path and moves the brewed coffee from the lower chamber  1220  to the coffee chamber  1290 , 
     (f) then introduce a second volume of water into the lower chamber  1220 , and 
     (g) repeat steps (b)-(e) one or more times, hence allowing the brewing and extraction processes to repeat with a fresh volume of solvent. 
     Subsequently, the multiple volumes of brewed coffee are combined in the coffee chamber  1290 , which can then be emptied by the operator, with the brewed coffee ready for consumption. In some embodiments, instead of adding fresh solvent to the grinds, the same volume of solvent is used when repeating steps (b)-(e). 
       FIGS. 11 and 12 , discussed above, illustrate multiple extraction coffee brewers that need not include an extraction acceleration device.  FIGS. 1-10 , also discussed above, and  FIGS. 13A-17 , discussed below, illustrate representative accelerated extraction devices, that can be used with one or more of the multiple extraction processes previously and/or described below. For example, a representative system  1300  shown in  FIG. 13A  includes (a) a brew chamber  1310 , (b) a coffee chamber  1320  (e.g., having a capacity of 200 mL or more), (c) an accelerated extraction device  1399 , (d) a water introduction device  1360 , and (e) a controller  1340  that is configured to produce more than one extraction of a given set of coffee grinds using the accelerated extraction device for at least one extraction. 
     Accordingly, the brew chamber  1310  can have a cavity for receiving coffee grinds, as well as an arrangement for preventing the coffee grinds from entering into the coffee chamber. One such arrangement includes a filter, e.g., a paper, cloth, or metal filter, as discussed above with reference to  FIG. 1 . Another arrangement for preventing the coffee grinds from entering the coffee chamber is a flow path that requires a pump for extraction. After brewing but prior to activating the pump, the grinds are separated from the brewed coffee, for example through compaction of the grinds, allowing only the brewed coffee that is not absorbed by the separated grinds to be subsequently pumped into the brew chamber (in other words, the brewed coffee is separated from the grinds, for example via compaction, after which only the brewed coffee is pumped into the coffee chamber). This system can accordingly include a plunger (such as a plunger typically used with a French press) to perform the compaction process, as discussed later with reference to  FIGS. 14 and 15 . In another embodiment, the process can be performed via a centrifuge, which, in at least some embodiments, eliminates the need for a physical filter, as discussed later with reference to  FIG. 17 . In any of these embodiments, the brew chamber is capable of accepting water for brewing coffee via a water introduction device. The coffee chamber receives the brewed coffee after brewing and, in at least some embodiments, the brewed coffee is further processed either in transit from the brew chamber to the coffee chamber or prior to removal from the device for serving. In other embodiments, the brewed coffee is provided directly to the coffee chamber and/or other suitable serving device. 
     In several of the embodiments described herein, the brew chamber or the coffee chamber, or any intermediate chamber anywhere along the flow path of the brewed coffee is coupled to an accelerated extraction device. The accelerated extraction device causes the brewed coffee to flow from the brew chamber to the coffee chamber at a rate that is higher than the flow rate (which may be zero) of the system prior to the activation of the accelerated extraction device. The accelerated extraction device may include, for example, a pressure source (positive or negative) such as a plunger, a pump, a vacuum piston, or a centrifuge, acting on a combination of brewed coffee and coffee grinds in the brew chamber, and extracting the brewed coffee. For example, the brewed coffee can be forced through a filter/porous material or compacted grinds. Compacted grinds can allow the use of an espresso-like large-hole filter. By activating an accelerated extraction device that includes a pressure source, brewed coffee is forced through a filter, rather than simply dripping through the filter by force of gravity, hence accelerating the extraction. 
     In another embodiment, the accelerated extraction device can rapidly remove brewed coffee from the brew chamber, after the brewed coffee has been separated from the coffee grinds, for example, via compaction. The accelerated removal may be achieved by pumping out the separated brewed coffee into the coffee chamber, or alternatively, pumping the brewed coffee into a secondary filtration vessel whereby the brewed coffee may undergo a second filtration operation. The second filtration operation may be desirable if some coffee grinds are still present in the brewed coffee, after the initial separation and prior to entering the coffee chamber. As this case demonstrates, the brewed coffee may travel through one or more other additional compartments that filter or otherwise process the brewed coffee prior to entering the coffee chamber. 
     In still further embodiments, the accelerated extraction device may implement other techniques to separate a fixed volume of brewed coffee from a given set of coffee grinds and introduce the brewed coffee into the coffee chamber in a manner that is faster than the separation rate prior to activating the accelerated extraction device. 
     The system  1300  includes a controller  1340  that has been configured to extract multiple volumes of brewed coffee from a fixed set of coffee grinds. The controller  1340  can be mechanical or electrical; for example, the controller can be a microcontroller that directs the action of the water introduction device and the accelerated extraction device electronically. A representative controller is configured to perform at least the following steps, in the following order. 
     Method A: 
     (1) combine hot water with coffee grinds so that the water will brew coffee for some period greater than three seconds, e.g., cause the water introduction device to introduce water into the brew chamber (where the grinds have already been placed), or cause a grind dispenser to dispense grinds into the brew chamber (where the hot water has already been placed), 
     (2) cause the accelerated extraction device to accelerate the extraction of at least a portion (but not necessarily all) of the brewed coffee from the brew chamber into the coffee chamber, and 
     (3) cause the water introduction device to introduce additional water into the brew chamber, which will brew using the same coffee grinds from step 1 and later be combined with the coffee brewed in step 2 prior to serving. 
     Method B: 
     (1) cause the water introduction device to introduce water into the brew chamber, where the water will brew coffee, 
     (2) allow all or a portion of the water to enter into the coffee chamber via a method that does not utilize an accelerated extraction device, 
     (3) cause the water introduction device to introduce additional water into the brew chamber, and 
     (4) cause the accelerated extraction device to extract at least a portion (but not necessarily all) of the additional brewed coffee from the brew chamber into the coffee chamber, combining with the coffee brewed in step 2 prior to serving. 
     Accordingly, the initial quantity of water can drip (or otherwise pass) through a set of coffee grinds, and the additional water can be rapidly extracted. Accordingly, the accelerated extraction device can accelerate a flow of coffee that would otherwise have a non-zero flow rate. To achieve certain coffee brew characteristics, it may be desirable to conduct a brief drip extraction at a low volume of water, followed by a one or more accelerated extractions. In this arrangement, it is not necessary for the accelerated extraction device to act upon the water/grinds more than once to achieve multiple extractions. In another embodiment of this arrangement, the steps can be reversed, e.g., the coffee formed from an initial volume of water is extracted in an accelerated fashion and the additional volume of water is allowed to extract via gravity or through other forces. 
     The disclosed systems are not limited to traditional coffee brewing device geometries. Instead, the brew chamber, coffee chamber, and accelerated extraction device can have a variety of suitable configurations/orientations with respect to one another in different embodiments. Furthermore, one or more additional brewing elements and/or brewing chambers may be present in the system, which can facilitate the process of brewing coffee. For example, the brew chamber can include an agitation device, as discussed above with reference to  FIGS. 2 and 6 . 
       FIGS. 13B and 13C  are diagrams of the coffee brewing Methods A and B, respectively, described above. Solid lines indicate steps required for particular embodiments, and dashed lines indicate optional steps, which may occur several times. For Method A, after step 3, either step 3a or step 2 occurs at least once. For Method B, step 3a occurs at least once. 
     Embodiments of the foregoing and following processes differ from espresso processes in one or more of multiple ways. For example, the size of the coffee chamber can be at least 200 mL. As another example, the disclosed processes include brewing the coffee, rather than allowing a continuous stream of water through it. As another example, the disclosed process can be achieved using significantly lower positive pressure than the 9-10 bars typically utilized in brewing espresso, or no positive pressure. In embodiments for which a continuous stream is run through the grinds, the stream is intermittent, yielding multiple extractions and hence creating multiple distinct solid-liquid phase partition equilibria. 
       FIG. 14  illustrates a system  1400  having a modified French press arrangement designed to allow for multiple accelerated extractions. A brew chamber  1410  holds the coffee grinds  1450 . A corresponding controller  1440  is configured to: 
     (1) cause water to be introduced to the grinds via a water introduction device  1464  (e.g., a water introduction pump), taking in water from a boiler  1460 , 
     (2) then allow the coffee to brew in the brew chamber  1410  until the grinds  1450  have been exposed to the water a sufficient amount of time to achieve the desired brew characteristics. Time spent brewing affects the character of the brewed coffee, including its strength, bitterness, and flavor profile, 
     (3) then, once this period has elapsed, direct a French press mesh filter  1412  to descend into the brew chamber  1410  via a piston  1490  (e.g., electrically controlled), with the combination of the French press mesh filter  1412  and the piston  1490  acting as the accelerated extraction device. This causes the brewed coffee to separate from the grinds (as shown in  FIG. 15 ), 
     (4) then causes a brewed coffee extraction pump  1401  to pump the brewed coffee, now separated from the grinds  1450 , into a coffee chamber  1420 , (5) then raise the French press mesh filter  1412  via the piston  1490 , subsequently introducing a second volume of water into the brew chamber  1410  and onto the previously brewed, non-replaced coffee grinds  1450 , and optionally agitating the grinds with an optional agitation device (see  FIG. 6 ) to distribute the grinds more evenly throughout the new volume of water, and 
     (6) repeat steps 1-4 one or more times, to allow the extraction process to repeat with a fresh volume of solvent (water), and subsequently combine the multiple volumes of brewed coffee in the coffee chamber  1420 , which can then be emptied by the operator, with the brewed coffee ready for consumption. 
     In another embodiment, the functions provided by the brewed coffee extraction pump  1401  and the water pump  1464  can be combined into a single pump that is selectively coupled to the boiler  1460  or the brew chamber  1410  via one or more valves under the control of the controller  1440 . 
       FIG. 16  illustrates a system  1600  configured in accordance with another embodiment in which the brewed coffee is restricted from entering the coffee chamber  1620  until a valve is actuated by a corresponding controller  1640 . A representative brew chamber  1610  can have a grind basket configuration that serves as a brew chamber and that holds the grinds  1650  while water is dripped over the grinds via a water pump  1664  or via gravity, or via another pressure source. The water can be delivered from a boiler  1660  to a spray head  1665  for delivery. The coffee chamber  1620  can include a carafe or other holding vessel that receives and contains brewed coffee  1651 . The controller  1640  can: 
     (1) direct the pump  1664 , serving as the water introduction device, to direct a volume of water from the boiler  1660  into the brew chamber  1610 , 
     (2) then wait a pre-specified, pre-calculated time (e.g., for a given weight of grinds), after which the coffee has brewed sufficiently without any communication between the brew chamber  1610  and the coffee chamber  1620 , after which a coffee flow path valve  1641  is actuated, opening a flow path between the brew chamber  1610  and the coffee chamber  1620 , 
     (3) then wait a pre-specified, pre-calculated time (e.g., for a given weight of grinds), after which the water has substantially completed brewing by dripping into the coffee chamber  1620 , 
     (4) then close the coffee flow path valve  1641  to close the flow path from the grind basket (brew chamber  1610 ) to the carafe (coffee chamber  1620 ), 
     (5) then introduce a second volume of water into the brew chamber  1610  to allow the extraction process to repeat with a fresh volume of solvent (e.g., water). 
     In the foregoing embodiment, the valve  1641  operates as an accelerated extraction device. Before the valve  1641  is actuated (opened), the brewed coffee  1651  is in liquid communication with the grinds  1650  in the brew chamber  1610 . When the valve  1641  is opened, the pressure differential (created by the hydraulic head of the brewed coffee  1651  in the brew chamber  1610 ) forces the brewed coffee into the coffee chamber  1620 . 
       FIG. 17  illustrates a representative example of a centrifugal system  1700  designed to allow for multiple accelerated extractions. The brew chamber  1710  includes a centrifuge  1711  that holds coffee grinds  1750 . A corresponding controller  1740  is configured to: 
     (1) cause water to be introduced to the grinds  1750  via a water introduction pump  1764 , acting as the water introduction device, taking in water from a boiler  1760 , 
     (2) then allow the coffee to brew in the centrifuge  1711  until the grinds  1750  have been exposed to the water a sufficient amount of time for the desired brew flavor characteristics, 
     (3) then, once this period has elapsed, direct the centrifuge  1711  to spin at a sufficient rate to cause the brewed grinds  1750  to compress along the sides of the brew chamber  1710  (as shown in dashed lines), separating the brewed coffee  1751  from the compressed grinds  1750   a,    
     (4) then cause a brewed coffee extraction pump  1701  to pump the brewed coffee  1751 , now separated from the grinds  1750   a,  into a coffee chamber  1720 , collecting in the coffee chamber, 
     (5) then subsequently introduce a second volume of water into the centrifuge  1711  combining with the previously brewed, non-replaced coffee grinds  1750 , and optionally agitating the grinds with an optional agitation device (not shown) to distribute the grinds more evenly throughout the new volume of water/agitate during the brew cycle, and 
     (6) repeat steps 1-4 one or more times, hence allowing the extraction process to repeat with a fresh volume of solvent, and subsequently combining the multiple volumes of brewed coffee in the coffee chamber  1720 , which can then be emptied by the operator, with the brewed coffee ready for consumption. 
     3.0 Representative Systems with Removable Brew Chambers 
       FIGS. 18-29C  illustrate coffee brewing systems that include removable brew chambers configured in accordance with several embodiments of the present technology. Such systems can be used to produce coffee via single-extraction and/or multiple-extraction processes. Generally, the systems include a vacuum source that provides the pressure differential used to direct coffee from the brew chamber to the coffee chamber. Accordingly, the systems can include a releasable connection along a flow path that joins and includes the brew chamber and the coffee chamber. In particular embodiments, the releasable connection in turn includes a releasable vacuum seal. In other embodiments, as described further later, the pressure differential device can include a pressure source. 
       FIG. 18  is a partially schematic illustration of a representative system  1800  that includes a coffee chamber  1820  releasably coupled to a brew chamber  1810  via a coffee outlet coupling  1812 . The system can be configured for single and/or multiple extraction processes. The brew chamber  1810  carries a filter device  1830  that can be sealed within the brew chamber  1810  via a sealing element  1833 , e.g., an O-ring, gasket, or other suitable element. The brew chamber  1810  is releasably coupled to the coffee chamber  1820 , e.g. via a coffee outlet conduit  1811  (carried by and/or attached to the brew chamber  1810 ) and a coffee inlet conduit  1823  (carried by and/or attached to the coffee chamber  1820 ). In other embodiments, the system  1800  includes other arrangements that provide a releasable and reattachable fluid communication link between the brew chamber  1810  and the coffee chamber  1820 . In a particular embodiment, the brew chamber  1810  is coupled and/or attached via a single generally horizontal motion along only a single generally horizontal axis, as indicated by arrow A, and decoupled and/or detached via a single, generally horizontal motion in the opposite direction, as indicated by arrow D. In other embodiments, the motion can include multiple steps along only a single axis, e.g., a ratchet-type motion. As used herein, “generally horizontal” refers to an orientation that is within ±20° of horizontal. In particular embodiments, the orientation can be within ±10°, ±5° or ±1° of horizontal. The same ranges apply to single-axis motion along other axes, e.g., vertical axes, as described later with reference to  FIGS. 29B, 29C . In any of these embodiments, the coupling  1812  can include an O-ring  1813  or any other suitable pressure-tight, releasable connector element. In other embodiments (as discussed later with reference to  FIGS. 29A-29C ), the coupling/decoupling motion can be along other axes. In general, the connection can include a quick-disconnect connection that facilitates a rapid and simple process for coupling and decoupling the brew chamber  1810 . This is distinct from existing arrangements that require at least a partial deconstruction or disassembly process to remove the brew chamber. 
     In a particular embodiment, the system  1800  can also include a locking mechanism  1870 , shown schematically as a latch in  FIG. 18 , to releasably secure the brew chamber  1810  in position when it is attached. The locking mechanism  1870  can be disengaged and/or unlocked to allow the brew chamber  1810  to be removed. In a particular embodiment, the locking mechanism  1870  is manually disengaged, e.g., by rotating the latch mechanism upwardly, as show in dotted lines in  FIG. 18 . Accordingly, the motion required to unlock the brew chamber  1810  is different than (and in a different direction than) the motion required to disengage the brew chamber  1810 . In other embodiments, the unlocking motion can be along the same axis as the disengaging motion (e.g., pushing to unlock and pulling to disengage). In still further embodiments, the locking mechanism  1870  can be automatically locked and unlocked. For example, the locking mechanism  1870  can include an actuator that automatically disengages the locking mechanism  1870  when the level of coffee within the brew chamber  1810  falls below a threshold level, e.g., indicating that the process of brewing the coffee and directing the coffee into the coffee chamber  1820  is complete. An advantage of the locking mechanism is that it can prevent the user from inadvertently removing the brew chamber  1810  when it still contains a significant amount of coffee. 
     In particular embodiments, other aspects of the system  1800  can be automated, in addition to or in lieu of automating the locking mechanism  1870 . For example, the system  1800  can include an automated driver  1890  that automatically attaches and detaches the brew chamber  1810 . In a particular aspect of this embodiment, the automated driver  1890  can include a lead screw  1891  that drives the brew chamber into engagement with a coupling at the end of the coffee inlet conduit  1823 , as indicated by arrow A, and out of engagement with the coffee inlet conduit  1823 , as indicated by arrow D. One or more rails or other guide elements can guide the motion of the brew chamber  1810  and prevent it from rotating under the torque imparted by the lead screw  1891 . 
     The system  1800  can include a boiler or water heater  1860  that heats water and directs the heated water into the brew chamber  1810  via a water inlet conduit  1863 . In a representative embodiment, the brew chamber  1810  includes an agitator (not shown in  FIG. 18 ) that stirs the coffee as it is being brewed. The agitator can include any of the arrangements described above. An advantage of the agitator is that it can produce more uniform and more completely brewed coffee through more uniform dispersal of the grinds throughout the added water, and can eliminate the need for a more complex showerhead-type device for introducing the hot water into the brew chamber  1810 . Eliminating the showerhead device can also reduce thermal losses during the brewing process. Optionally, the system  1800  can include a heater (e.g., an infrared lamp, silicone rubber heater, and/or induction heater) co-located with the brew chamber  1810  to keep the contents of the brew chamber  1810  hot during the brewing process. 
     As described above, the brew chamber  1810  can be releasably coupled to the coffee chamber  1820 , e.g., via a releasable connection to the coffee inlet conduit  1823 . The coffee inlet conduit  1823  can have an inverted U-shaped design, as indicated in  FIG. 18  so as to deliver coffee effectively into the coffee chamber  1820 . The coffee chamber  1820  can include an outer wall  1822  and an inner wall  1821 , and is coupled to a pressure differential device  1805 , e.g., a vacuum source  1801 , via a vacuum outlet conduit  1824 . A vacuum valve  1841   a  controls the fluid communication between the vacuum source  1801  and the coffee chamber  1820 . When the vacuum valve  1841   a  is open, the vacuum applied to the coffee chamber  1820  draws coffee from the brew chamber  1810  into the coffee chamber  1820  via the coffee outlet conduit  1811  and the coffee inlet conduit  1823 . When the vacuum valve  1841   a  is closed (e.g., after all or generally all the coffee in the brew chamber  1810  has been directed to the coffee chamber  1820 ), the coffee in the coffee chamber  1820  may be removed by opening a release valve  1841   b,  so as to direct the coffee through a release valve inlet  1825  and release valve outlet  1826  into a suitable carafe or other vessel. As used herein, the term “generally all” as applied to the amount of coffee removed from the brew chamber means that no coffee is flowing out of the brew chamber, or the flow of coffee has been reduced to a drip (as distinguished from a stream). 
       FIG. 19  illustrates a particular arrangement in which the coffee chamber  1820  includes an inverted vessel  1829  positioned within a housing  1839 . The vessel  1829  can be releasably connected to the housing  1839  via an interface  1827 . In a particular embodiment, the interface  1827  includes a threaded attachment between an end of the vessel  1829  and a correspondingly threaded base  1828  of the housing  1839 . Accordingly, the vessel  1829  can be easily removed, e.g., for cleaning and/or servicing. 
       FIGS. 20-23  illustrate further features of the brew chamber  1810  in accordance with particular embodiments of the present technology. Beginning with  FIG. 20 , the brew chamber  1810  can have a partially conical shape, and can include a handle  1814  that allows the brew chamber  1810  to be easily moved back and forth for attachment (as indicated by arrow A) and detachment (as indicated by arrow D). The handle  1814  can be formed from, or can include, an insulative material to make it more comfortable to grasp when the brew chamber  1810  is hot. Suitable materials include plastic, rubber and silicone. The brew chamber  1810  itself can be formed from stainless steel or another suitable food-grade material. The brew chamber  1810  can be open-topped, or can include a lid. When a lid is included, it can be deliberately not sealed, or can include releasable seal (e.g., an openable orifice) so as to allow the vacuum source  1801  ( FIG. 18 ) to withdraw the brewed coffee. 
     In still a further embodiment, the lid can remain sealed to facilitate the brew chamber  1810  being pressurized (e.g., in a manner generally similar to that described above with reference to  FIGS. 8 and 9 ). Accordingly, the vacuum source  1801  described above with reference to  FIG. 18  can be replaced with a pressure source that is coupled directly to the brew chamber  1810  rather than to the coffee chamber  1820 . 
     The filter device  1830  within the brew chamber  1810  can include a filter platform or support  1831  releasably sealed to the sides of the brew chamber  1810  via an O-ring  1833 . The filter platform  1831  can releasably support and/or carry a filter element  1832 . The filter platform  1831  can be formed from stainless steel, PTFE, and/or another suitable food grade material. The filter element  1832  can include paper, metal, plastic, cloth, glass, and/or other suitable materials configured for single use or multiple uses. In any of these embodiments, coffee grounds  1850  are placed on or in the filter element  1832  during operation, before or after the brew chamber  1810  is coupled to the coffee chamber  1820 , depending upon the particular embodiment. Hot water introduced into the brew chamber  1810  forms brewed coffee  1864 . Once the brewing process is complete, the vacuum applied by the vacuum source  1801  ( FIG. 18 ) directs the brewed coffee  1864  downwardly through the filter device  1830 , laterally through the coffee outlet conduit  1811 , and upwardly toward a coffee outlet port  1815 , as indicated by arrows C. 
       FIG. 21  is a side view of a representative brew chamber  2100  having a configuration generally similar to that discussed above with reference to  FIG. 20 . The brew chamber  2100  includes a handle  2114  positioned opposite from a corresponding coffee outlet port  2115 . The coffee outlet port  2115  receives brewed coffee from within the brew chamber  2100  via a coffee outlet conduit  2111 . Pedestals, feet or other support elements  2116  positioned at the base of the brew chamber  2100  allow the brew chamber  2100  to be placed in a stable configuration on any flat surface (despite the presence of the coffee outlet conduit  2111 ) when removed from the coffee brewing system, for example, to fill the brew chamber  2100  with coffee grounds. The low profile orientation of the coffee outlet conduit  2111  (e.g., running horizontally beneath the brew chamber  2100 ) can provide advantages relative to existing brew chambers. In particular, some existing brew chambers, such as those commonly used in siphon brewing devices, include a long, downwardly-extending tube for draining the coffee within. As a result, the coffee chamber cannot be placed on a flat surface without the aid of a tall stand. Such an arrangement can be cumbersome because (a) it requires an additional piece of equipment (the stand), and/or (b) it can be more easily knocked over (due to the height of the stand). 
       FIG. 22  shows the brew chamber  2100  in an inverted position, further illustrating the coffee outlet conduit  2111  and the coffee outlet port  2115 . 
       FIG. 23  is an enlarged illustration of the coffee outlet port  2115 . In a particular embodiment, the brew chamber  2100  can include one or more alignment features  2117  (e.g., apertures) that mate with corresponding alignment features (e.g., projections) carried by the portion of the brewing system to which the brew chamber  2100  is connected. A coupling  2170  provides a fluid-tight (e.g., air-tight), releasable connection between the brew chamber  2100  and the coffee inlet conduit  1823  ( FIG. 18 ). In a particular embodiment, the coupling  2170  includes a coupling body  2171  carrying an O-ring  2172  that sealably mates with the coffee outlet port  2115 . The coupling body  2171  can further include a connector  2173  for connection to the coffee inlet conduit  1823  ( FIG. 18 ). In another embodiment, the brew chamber  2011  can include one or more projections that mate with corresponding alignment apertures carried by the portion of the brewing system to which the brew chamber  2100  is connected. 
       FIG. 24  illustrates a representative filter platform  2431 , which supports a corresponding filter element, which in turn supports the coffee within the brew chamber  2100  described above. The filter platform  2431  can include openings  2432  that allow the brewed coffee to pass through. In particular embodiments, the openings are made large enough to allow brewed coffee to pass through at a suitable rate, yet small enough to prevent a filter element (e.g., a paper filter element) from tearing under the force applied to by the vacuum source  1801  ( FIG. 18 ). In a representative embodiment, the openings  2432  have a diameter of about 0.125 inch. 
       FIG. 25  is an enlarged illustration of the filter platform  2431 , as seen from below. The filter platform  2431  includes an upper portion  2434   a,  a lower portion  2434   b,  and a sealing element  2433  (e.g., an O-ring) between the upper and lower portions  2434   a,    2434   b.  The upper and lower portions support the O-ring  2433  in an orientation that allows it to seal against the sidewalls of the brew chamber  1810 . The lower portion  2434   b  can include standoffs  2435  that offset the exits of the openings  2432  from the base of the brew chamber  1810  into which the filter platform  2431  fits. Accordingly, brewed coffee can readily pass through the openings  2432  into the gap beneath the lower portion  2434   b,  and then to the coffee outlet conduit  2111  ( FIG. 21 ). The standoffs  2435  can be sized and positioned to prevent or at least restrict the filter platform  2431  from bowing downwardly under the force provided by the vacuum source  1801  ( FIG. 18 ). 
       FIG. 26  is a cut-away illustration of a representative brew chamber  2110  in which the filter platform  2431  is positioned. As shown in  FIG. 26 , the O-ring  2433  seals against an inwardly facing brew chamber wall  2612 , and the standoffs  2435  position the downwardly facing surface of the lower portion  2434   b  away from the floor  2613  of the brew chamber. 
     In a particular embodiment, a generally conical, flat-bottomed paper or metal filter can be placed on top of the upper portion  2434   a  for support. In another embodiment, the filter platform  2431  can support a flat filter element. For example,  FIG. 27  illustrates a flat, metallic (e.g., stainless steel) mesh filter element  2732  positioned on the upper surface of the filter platform  2431  and secured in position with one or more retention elements  2733 . In an embodiment shown in  FIG. 27 , the retention element  2733  is a ring-line structure that interfaces and rotates to lock with grooved slots in the filter platform  2431  and seals the filter element  2732  to secure the filter element  2732  in place. 
     In the embodiments shown in  FIGS. 25 and 26 , the standoffs  2435  project from the bottom of the filter platform  2431  to offset it from the base of the brew chamber  2110 . In other embodiments, the brew chamber  2110  itself can include features that allow brewed coffee to pass from the brew chamber into the coffee outlet conduit  2111  ( FIG. 21 ). For example,  FIGS. 28A-28D  schematically illustrate the base of a corresponding brew chamber  2810  (as seen from above) along with corresponding indentation patterns  2836   a - 2836   d.  The indentation patterns can be machined, milled, stamped, cast, molded, and/or otherwise formed into the floor  2813  of the brew chamber, and can direct brewed coffee exiting the brew chamber to the entrance of the coffee outlet conduit  2111 , eliminating the need for a filter platform  2431 . 
     In a particular embodiment described above with reference to  FIG. 20 , the coffee outlet port  1815  is positioned toward the top of the corresponding brew chamber  1810 . In another embodiment, illustrated in  FIG. 29A , a representative brew chamber  2910   a  can include a coffee outlet port  2915   a  positioned toward the bottom of the brew chamber  2910   a.  A corresponding coupling  2970  provides a releasable connection between the brew chamber  2910   a  and the rest of the coffee brewing system, and can include an O-ring  2972  and multiple alignment features, shown as first alignment features  2917   a  and second alignment features  2917   b.  In a particular embodiment, the first alignment features  2917   a  can include tabs, projections, or pins (e.g., tapered pins), and the second alignment features  2917   b  can include corresponding apertures that receive the tabs, projections, or pins to guide the motion of the brew chamber  2910   a  as it is attached (as indicated by arrow A) and detached (as indicated by arrow D). 
     In further embodiments, the brew chamber can be attached via motion in directions other than generally horizontal. For example, referring now to  FIG. 29B , a representative brew chamber  2910   b  includes a coffee outlet port  2915   b  that faces upwardly. Accordingly, the brew chamber  2910   b  can be attached by moving it upwardly as indicated by arrow A, and can be detached by moving it downwardly as indicated by arrow D, e.g., along only a generally vertical axis. In such an embodiment, the brew chamber  2910   b  can be further secured to the overall system, for example, by rotating a horizontal flange carried by the brew chamber  2910   c  into a horizontal slot carried by the structure to which the brew chamber  2910   b  is attached. Accordingly, the brew chamber  2910   b  will not fall downwardly from the rest of the system  1800  after it is attached. 
     In another embodiment shown in  FIG. 29C , a representative brew chamber  2910   c  can include a downwardly facing coffee outlet port  2915   c  that can be engaged by moving the brew chamber  2910   c  downwardly (as indicated by arrow A), and can be disengaged by moving the brew chamber upwardly as indicated by arrow D, e.g., along only a generally vertical axis. 
       FIG. 30  is a partially schematic illustration of a coffee brewing system  3000 . The system  3000  can include two coffee chambers  3020 , each of which receives coffee from a corresponding brew chamber positioned within a housing  3001 , via corresponding coffee inlet conduits  3023 . In a particular embodiment, the system  3000  can include two corresponding coffee urns  3030 , each of which receives coffee from a corresponding one of the coffee chambers  3020 . Other system features generally similar to those discussed above (including, for example, removable or non-removable brew chambers, a controller, an agitation device, an accelerated extraction device, among others) can be housed out of sight within the housing  3001 . 
     One advantage of brew chambers having the coffee outlet port toward the top of the brew chamber is that the likelihood for hot brewed coffee to spill from the brew chamber if the brew chamber is inadvertently removed before being drained, is significantly reduced. Accordingly, if the brew chamber includes a coffee outlet port toward the bottom of the brew chamber, as described above with reference to  FIGS. 29A and 29C , the brew chamber can include a valve that is normally closed, and opens only when the brew chamber is successfully attached or engaged. 
     In any of the foregoing embodiments, the brew chambers can include quick-release, fluid-tight connections between the brew chamber and the rest of the brewing system. One advantage of this feature is that it allows the brew chambers to be quickly and easily detached so as to remove spent grounds, and then quickly and easily reattached with fresh grounds onboard. Another advantage is that it allows the brew chamber to be easily removed for periodic cleaning. 
     Still another advantage of at least some of the foregoing embodiments is that the entire volume of hot brewing water can remain in contact with the coffee grinds for a significantly longer period of time than is possible with drip brewers, which drip coffee extracted at varying concentrations throughout the brew process into a coffee holding vessel, such as a carafe. This feature, alone or in combination with agitating the coffee and grounds while in the brew chamber, can increase the uniformity of the extraction, which is commercially desirable. In addition, the force of the vacuum can quickly remove the entire volume of brewed coffee from the brew chamber once the desired extraction point has been achieved. Accordingly, this provides the operator with the ability to control the brew time with a higher degree of specificity than drip brewers, while also ensuring that coffee grinds are not exposed to different water levels for long periods, which would result in a non-uniform extraction. 
     From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. For example, the pressurized brew chamber described above with reference to  FIG. 9  can be applied to any of the foregoing embodiments. A representative one-liter coffee maker can have a filter diameter of about 5 inches, and a representative two-liter coffee make can have a filter diameter of about 7 inches. In other embodiments, the filter diameters can have other suitable values, e.g., depending on the coffee volume, that produce relatively shallow grind beds suitable for multiple, quick extractions. For example, the filter can have a diameter of 12 inches for a 4-6-liter capacity, or a diameter of 1.5-2 inches for a single cup. Other suitable filter diameters range from 3 inches to 17 inches. The capacity of the brew chamber and/or the coffee chamber can range from about 1 liter or less (e.g., about 200 mL, which is significantly larger than typical espresso makers) to about 12 liters in particular embodiments. The brew chamber and/or the coffee chamber can have conical or partially conical shapes in certain embodiments, and can have other shapes (e.g., generally cylindrical shapes) in other embodiments. In particular embodiments, a pressure source or a vacuum source is used to produce the pressure differential of at least 60 torr between the brew chamber and the coffee chamber of the system. In other embodiments, the pressure source and the vacuum source can be activated simultaneously to produce the desired pressure differential. The first and second phases described above can be repeated once (as third and fourth phases), twice (as fifth and sixth phases) or more than twice. 
     In a particular embodiment, an operator (or automated controller) adds an initial volume of water to grinds, then quickly extracts and discards it, then performs multiple subsequent extractions on the already-wet grinds, and combines two or more of the subsequent extractions. Accordingly, only some of the extractions are combined, and the grinds are not necessarily dry for the first of the combined extractions. This process can be desirable, for example, for removing caffeine prior to performing/combining extractions that will be consumed. In particular, the caffeine typically extracts first, so discarding a quick initial extraction can remove some or all of the caffeine when desired. 
     The grinds can also have other dimensions in other embodiments. For example, in at least some embodiments for which the system produces brewed coffee via multiple extractions, the grind diameter can be larger than 600 μ. In particular such embodiments, the grind diameter can range up to about 1000 μ. 
     Certain aspects of the technology described in the context of the particular embodiments may be combined or eliminated in other embodiments. For example, the agitation device described above can be eliminated in particular embodiments. In some embodiments, the aspects of the brewing processes and systems described above in the context of an automated or partially automated arrangement can be conducted in a manual arrangement, and vice versa. A particular embodiment of the foregoing devices that includes accelerated extraction provided by a vacuum device may be used to brew tea (via multiple extractions) as well as (or instead of) coffee. Further, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the present technology. Accordingly, the present disclosure and associated technology can encompass other embodiments not expressly shown or described herein. The following examples provide further representative embodiments of the presently disclosed technology. 
     To the extent any materials incorporated by reference herein conflict with the present disclosure, the present disclosure controls. 
     EXAMPLES 
     1. A method for brewing coffee, comprising:
         placing ground coffee on a filter element of a brew chamber;
           directing heated water into the brew chamber and in contact with the ground coffee;   during a first phase, brewing coffee in the brew chamber without subjecting the coffee to a pressure differential of at least 150 torr between the brew chamber and a coffee chamber to which the brew chamber is coupled, the coffee chamber having a capacity of 200 mL or more; and   
           during a second phase, extracting the coffee from the brew chamber through the filter element and into the coffee chamber via a pressure differential of at least 150 torr between the brew chamber and the coffee chamber.       

     2. The method of example 1 wherein brewing the coffee includes brewing the coffee at atmospheric pressure. 
     3. The method of example 1 wherein the coffee remains in the brew chamber for a period of from 5 seconds to 5 minutes before being extracted from the brew chamber. 
     4. The method of example 1, further comprising drawing a vacuum on the coffee chamber to produce the pressure differential. 
     5. The method of example 4 wherein the pressure differential has a value of from 60 torr to about 759.999999999 torr. 
     6. The method of example 4 wherein the pressure differential has a value of about 585 torr. 
     7. The method of example 1, further comprising applying pressure to the brew chamber to produce the pressure differential. 
     8. The method of example 7 wherein the pressure differential has a value of at least one atmosphere. 
     9. The method of example 1, further comprising agitating the heated water and the ground coffee while the heated water is in the brew chamber. 
     10. The method of example 1 wherein placing ground coffee includes placing the ground coffee to have an average post-brew depth of less than 0.7 inches. 
     11. The method of example 1 wherein placing ground coffee includes placing the ground coffee to have an average post-brew depth of about 0.4 inches. 
     12. The method of example 1 wherein the operations of placing ground coffee, directing the heated water, and extracting the coffee are directed by an automated controller. 
     13. The method of example 1 wherein at least one of the operations of placing ground coffee, directing the heated water, and extracting the coffee is directed by an automated controller. 
     14. The method of example 1 wherein at least one of the operations of placing ground coffee, directing the heated water, and extracting the coffee is performed manually. 
     15. The method of example 1 wherein a volumetric capacity of the coffee chamber is from 1 to 12 liters. 
     16. The method of example 1 wherein extracting the coffee includes extracting the coffee with a period of from about 5 seconds to about 60 seconds. 
     17. The method of example 1 wherein the heated water is a first volume of heated water, and wherein the coffee is a first volume of coffee, and wherein the pressure differential is a first pressure differential, and wherein the method further comprises:
         directing a second volume of heated water into the brew chamber in contact with the ground coffee;   during a third phase, brewing a second volume of coffee in the brew chamber without subjecting the second volume of coffee to a pressure differential of at least 60 torr between the brew chamber and the coffee chamber; and   during a fourth phase, extracting the second volume of coffee from the brew chamber through the filter element and into the coffee chamber via a second pressure differential of at least 60 torr between the brew chamber and the coffee chamber.       

     18. The method of example 17, further comprising:
         placing a third volume of heated water in the brew chamber in contact with the ground coffee;   during a fifth phase, brewing a third volume of coffee in the brew chamber without subjecting the third volume of coffee to a pressure differential of at least 60 torr between the brew chamber and the coffee chamber; and   during a sixth phase, extracting the third volume of coffee from the brew chamber through the filter element and into the coffee chamber via a third pressure differential of at least 60 torr between the brew chamber and the coffee chamber.       

     19. A method for brewing coffee, comprising:
         placing ground coffee on a filter element of a brew chamber, wherein a median diameter of particles comprising the ground coffee is from about 200 microns to about 1000 microns, and wherein the filter element has a diameter of 3 inches to 17 inches;   placing a first volume of heated water in the brew chamber and in contact with the ground coffee for a period of up to 5 minutes;   drawing a vacuum on a coffee chamber that is in fluid communication with the brew chamber to extract a first volume of coffee from the brew chamber through the filter element and into the coffee chamber, with the vacuum creating a first pressure differential between the brew chamber and the coffee chamber of between 60 torr and 759.999999999 torr;   placing a second volume of heated water in the brew chamber in contact with the ground coffee for a period of up to 5 minutes; and   drawing a vacuum on the coffee chamber to extract a second volume of coffee from the brew chamber through the filter element and into the coffee chamber to mix with the first volume of coffee, with the vacuum creating a second pressure differential between the brew chamber and the coffee chamber of between 60 torr and 759.999999999 torr.       

     20. The method of example 19 wherein at least one of the first and second pressure differentials has a value of about 585 torr. 
     21. The method of example 19, further comprising, while the first volume of heated water is in the brew chamber, agitating the first volume of heated water and the ground coffee with a stream of gas introduced into the brew chamber. 
     22. A coffee brewing system, comprising:
         a brew chamber;   a coffee chamber having a capacity of at least 200 mL;   a filter device positioned along a fluid flow path joining the brew chamber to the coffee chamber;   a pressure differential device coupled to at least one of the brew chamber and the coffee chamber, the pressure differential device being configured to produce a pressure differential between the brew chamber and the coffee chamber of at least 150 torr; and   a hot water source coupled to the brew chamber.       

     23. The system of example 22 wherein the pressure differential device includes a vacuum source coupled to the coffee chamber. 
     24. The system of example 22 wherein the vacuum source is configured to draw a vacuum less than atmospheric pressure in a range of from about 20 torr to about 759.999999999 torr, absolute. 
     25. The system of example 22 wherein the pressure differential device includes a pressure source coupled to the brew chamber. 
     26. The system of example 22 wherein the pressure source is configured to produce a pressure of up to 10 atmospheres at the brew chamber. 
     27. The system of example 22, further comprising a controller programmed with instructions that, when executed, activate the pressure differential device. 
     28. The system of example 27 wherein the instructions, when executed: direct a first volume of hot water into the brew chamber;
         activate the pressure differential device to direct a first volume of coffee, formed from the first volume of water, into the coffee chamber;   direct a second volume of hot water into the brew chamber; and   activate the pressure differential device to draw a second volume of coffee, formed from the second volume of water, into the coffee chamber to mix with the first volume of coffee.       

     29. The system of example 27 wherein the instructions, when executed:
         direct a volume of hot water into the brew chamber;   retain the hot water in the brew chamber for a period of from 5 seconds to 5 minutes before being extracted from the brew chamber.       

     30. The system of example 29 wherein the instructions, when executed, activate the pressure differential device for a period of from 5 seconds to 60 seconds to direct coffee, formed from the volume of water, into the coffee chamber. 
     31. The system of example 22 wherein the filter device includes a re-useable support element and a disposable filter element. 
     32. The system of example 22 wherein the filter device includes a re-useable filter element. 
     33. The system of example 22, further comprising an agitation device coupled to the brew chamber to agitate coffee and hot water in the brew chamber. 
     34. The system of example 22 wherein the agitation device includes an aerator. 
     35. The system of example 22, further comprising a releasable clamp positioned to releasably secure the filter along the fluid flow path. 
     36. A coffee brewing system, comprising:
         a brew chamber;   a coffee chamber having a capacity of at least 200 mL;   a filter device positioned along a fluid flow path joining the brew chamber to the coffee chamber;   a vacuum source coupled to the coffee chamber, the vacuum source being configured to produce a pressure differential between the brew chamber and the coffee chamber of at least 60 torr;   a hot water source coupled to the brew chamber; and   a controller programmed with instructions that, when executed:
           direct a first volume of hot water into the brew chamber;   activate the vacuum source to force a first volume of coffee, formed from the first volume of water, into the coffee chamber;   direct a second volume of hot water into the brew chamber; and   activate the vacuum source to force a second volume of coffee, formed from the second volume of water, into the coffee chamber to mix with the first volume of coffee.   
               

     37. The system of example 36 wherein the instructions, when executed:
         retain each of the first and second volumes of hot water in the brew chamber for a period of from 5 seconds to 5 minutes before being extracted from the brew chamber;   activate the vacuum source for a period of from 5 seconds to 60 seconds to direct the first volume of coffee into the coffee chamber; and   activate the vacuum source for a period of from 5 seconds to 60 seconds to direct the second volume of coffee into the coffee chamber.       

     38. The system of example 36 wherein the coffee chamber has a maximum capacity of 12 liters. 
     39. The system of example 36 wherein the filter device includes a re-useable support element and a disposable filter element. 
     40. The system of example 36 wherein the vacuum source has a capacity of at least one CFM. 
     41. The system of example 40 wherein the vacuum source has a capacity of at least one CFM for at least 5 seconds.