Patent Publication Number: US-2022225819-A1

Title: Apparatus and method for preparing an iced tea or coffee beverage

Description:
TECHNICAL FIELD 
     This disclosure relates to iced coffee and tea beverages, a method for making the beverages and an apparatus for use in the method. In particular, the disclosure relates to an aerated ice beverage with a creamy mouthfeel and a long stability once prepared. 
     BACKGROUND 
     It is well known to provide consumers with ice in their beverages to provide greater refreshment. Beyond simply adding ice-cubes, it is well known to provide beverages such as slush-puppie® style drinks made by constantly agitating a strongly refrigerated beverage concentrate. Such scraped beverages contain small rough ice fragments and have a slurry-like mouthfeel for the consumer. 
     Alternatively, beverages may be produced by blending ice cubes with a beverage liquor to produce a beverage with ice flakes distributed therein. This relies on a high speed blender having cutting blades. An example of such beverages based primarily on coffee beverages are so-called Frappuccinos®. While such iced beverages are prepared with a pleasant appearance, they typically melt quickly when provided to the consumer and there is a consequent formation of a watery layer from the melted ice which is devoid of the flavouring present in the rest of the beverage. Furthermore, even when freshly prepared, the ice flakes are visible as agglomerates and are discernible to the consumer on drinking the beverage. 
     WO2014/135886 describes an apparatus for generating a slush containing frozen and non-frozen liquid. The slush is made from a draught beverage, such as beer, lager or cider. 
       FIG. 1  reproduces a diagrammatic view of the apparatus of WO2014/135886. The apparatus is in the form of a slush machine  18  and comprises a freeze conduit  3  for liquid  110 , the conduit having an inlet  103  and an outlet  104  defining a volume  105  therebetween. A pump  2  feeds liquid through the volume  105  from the inlet  103  to the outlet  104  where it is then re-circulated back to the inlet  103  via conduit  1 . Conduit  1  and freeze conduit  3  together define a conduit loop for recirculation of liquid. Slush can be dispensed from the loop from a dispensing outlet  8 , the loop being replenished via a conduit loop inlet  7  from a reservoir  17 . 
     An insulated slush recirculation umbilical  10  is added between the slush machine  18  and the dispensing outlet  8 . 
     The freeze conduit  3  forms one half of a heat exchanger  6  with a cooling conduit  108  having an inlet  106  and an outlet  107  and containing a body of liquid glycol coolant  109  therebetween. Heat exchanger  6  is connected to a coolant loop that, as indicated by arrow A, circulates the liquid coolant from the inlet  106  to the outlet  107  to a coolant refrigeration unit  22  and then back to the inlet  106 . The coolant is provided to the inlet of the cooling conduit at a temperature below the freeze point of the liquid; thus, when the coolant flows within the cooling conduit thermal heat transfer occurs from the liquid to the coolant. Coolant refrigeration unit  22  is a glycol chiller which includes a vapour compression refrigeration system  21  that is used to cool a reservoir of coolant  20 . Pump  19  is integrated into the chiller unit and provides the motive force to re-circulate the coolant. 
     The rate of flow of liquid coolant through the cooling conduit  108  can be varied, thereby varying the rate of heat transfer out of the liquid in the volume  105  of the freeze conduit  3 . By varying the flow rate of fresh coolant into the cooling conduit a net increase or decrease in the average temperature of the coolant within the cooling conduit is effected: this changes the overall thermal heat transfer rate from the working fluid to the coolant and hence the freeze rate in the working fluid flowing within the freeze conduit. 
     Flow through the cooling conduit is controlled by a valve  24 . A lower rate of heat transfer is achieved by shutting off the coolant fluid flow rate to substantially zero so that there is no flow of coolant through the cooling conduit  108 . A higher rate of heat transfer is achieved by opening valve  24  to allow flow of coolant through the cooling conduit  108 . 
     An additional coolant bypass loop  111  is provided for diverting coolant flow away from the cooling conduit  108 . Flow through this loop is controlled as required by a normally open valve  23 . 
     Valves  23 ,  24  are controlled by a controller  15  in dependence on a sensor  4  to sense the fraction of frozen liquid in the generated slush. The sensor  4  is provided in the conduit loop  1  immediately upstream of the conduit inlet  103 . The controller  15  can vary the heat transfer out of the liquid in volume  105  between different rates by controlling the flow of liquid coolant through the cooling conduit  108  in dependence on the output from the sensor  4 . In an idle state, the machine is only required to overcome the base energy gains in the system to maintain the ice/liquid ratio of the working fluid in the re-circulated loop to the pre-set level desired. Thus, the lower rate of heat transfer is set by shutting the valve  24  to prevent flow of coolant through the cooling conduit  108 . When dispense occurs, the volume of semi frozen working fluid dispensed is replaced with unfrozen working fluid from the reservoir  17 . This results in a rapid reduction in the solid fraction of the fluid within the re-circulated loop that is sensed by the sensor  4 , causing the control system to increase the rate of heat transfer out of the freeze conduit by opening valve  24   
     WO2018/122277 describes an apparatus and method for preparing an ice-containing tea or coffee beverage. The method comprises (i) providing a beverage liquor containing soluble tea or coffee solids, and a freezing-point suppressant; (ii) aerating the beverage liquor by the addition of a gas; (iii) flowing the aerated, preferably sweetened, beverage liquor through a refrigeration system to cool the aerated beverage liquor and to thereby form a plurality of ice crystals within the aerated beverage liquor; and (iv) dispensing the cooled aerated beverage liquor as an ice-containing tea or coffee beverage. 
       FIG. 2  reproduces a schematic of the apparatus of WO2018/122277. The apparatus  201  comprises a reservoir  205  for holding a beverage liquor. The reservoir  205  is connected via a supply duct  210  to a refrigeration circuit  215 . The refrigerant circuit  215  comprises a plastic duct  216  within which the liquor flows, which has a recycle loop to permit the liquor to recirculate within the circuit  215 . The refrigeration circuit  215  comprises a heat exchanger  220  for cooling the liquor using pre-chilled refrigerant which is flowed within a separate duct  225 . 
     The refrigeration circuit  215  is also in fluid communication with a dispensing outlet  230  for dispensing an ice-containing tea or coffee beverage from the refrigeration circuit  215  into a receptacle  235 . 
     A source of pressurised gas  240  is provided to supply pressurised gas into the supply duct  210  for aerating the beverage liquor. The gas may be supplied through a nozzle having a plurality of inlets to encourage the formation of fine bubbles. The gas mixing may also or alternatively involve a static mixer or one or more constricting orifices  241 . A pump  245  is also provided to circulate the beverage within the refrigeration circuit  215 . 
     The apparatus  201  allows the preparation of an ice-containing tea or coffee beverage. Beverage liquor containing soluble tea or coffee solids and a freezing point suppressant is pumped or driven with pressurised gas from the reservoir  205 , through the supply duct  210  to the refrigeration circuit  215 . Gas is dosed into the supply duct  210  from the gas source  240  via mixing means  241 . The liquor circulates, driven by the pump  245 , within the refrigeration circuit  215  and through the heat exchanger  220 , where it is cooled so that ice crystals form slowly. An ice-containing tea or coffee beverage is dispensed on demand from the circuit  215  via the outlet  230  into the beverage receptacle  235 . 
     While the apparatus of WO2014/135886 is able to generate a slush containing frozen and non-frozen liquid and the apparatus of WO2018/122277 is able to prepare an ice-containing tea or coffee beverage, it would be desirable to improve the apparatus described. 
     SUMMARY OF THE DISCLOSURE 
     According to a first aspect of the disclosure there is provided an apparatus for preparing an ice-containing tea or coffee beverage, the apparatus comprising:
         a) a beverage concentrate reservoir;   b) a water pre-chiller containing or supplied with water;   c) a mixer for mixing beverage concentrate from the beverage concentrate reservoir with water from the water pre-chiller to form a beverage liquor or constituent thereof;   d) a cooling unit containing a coolant;   e) an ice-generating system;   f) a beverage product circuit for supplying beverage liquor from the mixer to the ice-generating system;   g) an ice-generating cooling circuit for supplying coolant from the cooling unit to the ice-generating system to cool the beverage liquor and to thereby form a plurality of ice crystals within the beverage liquor;   h) a pre-chiller cooling circuit for supplying coolant from the cooling unit to the water pre-chiller to cool the water;   wherein a single cooling unit provides the coolant for both the ice-generating cooling circuit and the pre-chiller cooling circuit.       

     The present disclosure will now be further described. In the following passages different aspects of the disclosure are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous. 
     While the following description refers primarily to coffee beverages, it should be appreciated that the disclosure applies equally to tea beverages, i.e. to beverages comprising soluble tea and/or coffee solids. 
     The present apparatus and method relate to preparing an ice-containing tea or coffee beverage—a so-called iced tea or iced coffee beverage. Tea and coffee beverages are well-known and comprise dissolved tea and coffee solids. By way of example, a typical coffee beverage might be formed by reconstituting a spray- or freeze-dried coffee powder or by the extraction of roast and ground coffee beans. For the avoidance of doubt, a coffee beverage as defined herein is one produced from any part of the coffee plant, including elements from one or more of the coffee cherry, coffee husk, coffee beans, or coffee plant leaves. Similarly, a tea beverage is one produced from any part of a tea plant, typically an extraction from the leaves. The most preferred beverage is one made from coffee solids, such as are present in a standard coffee beverage, i.e. an espresso or cappuccino. Thus, the most preferred coffee solids are those obtained by extraction of a coffee bean. 
     According to the present apparatus and method, a beverage liquor is provided containing soluble tea or coffee solids which is cooled to thereby form a plurality of ice crystals within the beverage liquor. The beverage liquor may be formed by dilution of one or more concentrates, preferably liquid concentrates. For example, the beverage liquor may comprise a dilution of a beverage concentrate. A beverage liquor as defined herein refers to liquid used by or in the apparatus or method to form the beverage. Solids refer to those components of an aqueous solution which are left behind when all of the water is removed. Thus, for example, an instant soluble coffee powder may be considered the coffee solids of a dehydrated coffee extract. The solids are preferably soluble solids, but may contain small amounts of fine insoluble material. 
     The beverage liquor contains soluble coffee or tea solids. Preferably the liquor contains 0.5 to 6 wt %, by weight of the total beverage liquor of coffee or tea solids, more preferably from 1 to 5 wt % coffee or tea solids. This level of coffee or tea solids would typically provide a desirable strength of tea or coffee beverage. 
     The beverage liquor preferably also includes a freezing point suppressant in addition to the tea or coffee solids. As will be appreciated, a freezing point suppressant is an ingredient which reduces the temperature at which a liquid freezes. Generally any soluble ingredient will act to suppress the melting point of water, but the extent to which it affects the melting point will depend on the ingredient itself and the amount which is present. 
     The freezing point suppressant affects the ice-crystal growth. In a pure water/ice slush the ice is not particularly stable and is subject to a ripening process whereby small crystals tend to melt and larger crystals tend to grow. The presence of the freezing point suppressant serves to reduce this Ostwald ripening and allow the preservation of small ice crystals in the slush which is formed. The apparatus, method and system of the present disclosure favour the production of fine ice-crystals which are stabilised by the freezing point suppressant. 
     Preferably the beverage liquor comprises the freezing point suppressant in an amount sufficient to suppress the melting point of the beverage liquor by from 0.2 to 3° C. or more, preferably by from 0.4 to 1° C. This measurement is in comparison to the melting point of ice/water, and is based on the presence of the same concentration of the freezing point suppressant in a water solution. That is, this measurement disregards the presence of the tea and/or coffee solids which will also have a separate suppressing effect on the water. Melting point measurements are well known in the art. Preferably the melting point of the beverage liquor is suppressed to a temperature of −7° C. to −12° C. Beneficially, use of the freezing point suppressant may allow the end beverage as dispensed at a dispensing outlet into a receptacle to have a temperature of, for example, 0° C. to −1.5° C. 
     The freezing point suppressant may be any food-safe soluble ingredient such as a salt, an alcohol, a sugar, ice-structuring proteins or combinations of two or more thereof. It is most preferred that the freezing-point suppressant is a sweetener, such as a polyol or a sugar or a mixture thereof. The sweetener may be provided as a sweetener concentrate. 
     The most preferred freezing point suppressant is sugar, preferably sucrose and/or fructose. Suitable sugars include mono and disaccharides, preferably, sucrose, fructose, and/or glucose. A sugar replacement may be used in place of the sugar or a portion of the sugar. Suitable sugar replacements include polydextrose. If a sugar is included which has been separately refined from a coffee or tea material, then this is considered as part of the freezing point suppressant, rather than as part of the tea or coffee solids. 
     The use of conventional sugars permits the provision of a beverage made from simple, conventional beverage ingredients, such as coffee and sugar, and optionally milk, in a new form with a surprising physical appearance. Where the freezing point suppressant is sugar or another sweetener, the beverage liquor may be considered a sweetened beverage liquor. 
     Preferably the sweetened beverage liquor comprises 3.2 to 25 wt % sugar or sugar replacement, preferably 5 to 8 wt % sugar or sugar replacement. Preferably the sugar and/or sugar replacement is sucrose, fructose, polydextrose or a mixture thereof. In one example a mixture of 4 wt % fructose and 2.5 wt % polydextrose may be beneficially used. These amounts of sugar and/or sugar replacement are sufficient to depress the melting point, while also providing a desirable level of sweetness to the final beverage. 
     The beverage liquor may therefore comprise soluble coffee or tea solids and one or more sugars and/or sugar replacements, as well as the water forming the majority of the liquor. The beverage liquor may also include a dairy ingredient, such as milk or cream, preferably in an amount of less than 25 wt %, more preferably less than 10 wt %. The presence of such dairy ingredients in tea and coffee beverages is well known, such as for English breakfast tea, or for Lattes. 
     However, the presence of fat in the liquor, such as dairy fats from the inclusion of dairy ingredients affects the stability of the bubbles. In addition, the presence of high fat levels caused high viscosity increases during the cooling step, making the liquor difficult to pump and causing difficulty in providing a consistent ice fraction. Accordingly, the sweetened beverage liquor preferably comprises fats in an amount of less than 20 wt %, preferably less than 10 wt % and, preferably is substantially or completely free of fat. 
     The beverage liquor may further comprise other additives, such as flavourings, stabilisers, hydrocolloids (gums and thickeners), buffers, colouring agents, vitamins and/or minerals, and mouthfeel enhancers, or combinations of two or more thereof. These further additives preferably comprise less than 5 wt % of the beverage liquor, more preferably less than 1 wt % of the beverage liquor. Such additives as gums and thickeners are well-known to help stabilise thicker beverages such as iced coffees, but are considered by consumers to be unhealthy. Beneficially the beverage produced by the present apparatus and method can be very stable despite the absence of such ingredients. 
     Most preferably the beverage liquor is free from any such further additives and, therefore, the beverage liquor consists of only tea or coffee solids, a freezing point suppressant such as one or more sugars, and water, and optionally any dairy ingredient. Preferably the beverage liquor is free from any dairy ingredients. 
     Preferably, the ice-generating cooling circuit is configured to maintain a continuous flow of coolant to the ice generating system. Optionally the pre-chiller cooling circuit is configured to permit intermittent flow of coolant to the water pre-chiller. 
     Preferably, the pre-chiller cooling circuit comprises a heat exchanger that is cooled by the coolant, wherein the heat exchanger is, or is in thermal contact with, the water pre-chiller. 
     Preferably, the water pre-chiller and/or heat exchanger is additionally in thermal contact with the beverage concentrate reservoir and/or the mixer. 
     The heat exchanger may comprise one or more metal, preferably aluminium, blocks, wherein coolant may pass through one or more coolant bores in the one or more metal blocks and water may pass through one or more water bores in the one or more metal blocks. 
     The beverage concentrate reservoir may be in contact with the one or more metal blocks. Optionally the one or more metal blocks may be in face-to-face contact with a face of the beverage concentrate reservoir. 
     The apparatus may further comprise a sweetener concentrate reservoir. The mixer may be configured for mixing sweetener concentrate from the sweetener concentrate reservoir with water from the water pre-chiller to form a constituent of the beverage liquor. 
     Preferably, the sweetener concentrate reservoir is thermally isolated from the water pre-chiller and/or heat exchanger. 
     The mixer may comprise a first pre-mixer for mixing the beverage concentrate from the beverage concentrate reservoir with the water from the water pre-chiller, a second pre-mixer for mixing the sweetener concentrate from the sweetener concentrate reservoir with the water from the water pre-chiller, and a mixing chamber that receives an output from the first pre-mixer and an output from the second pre-mixer and is configured to mix the outputs together to form the beverage liquor. 
     The apparatus is preferably for preparing an aerated ice-containing tea or coffee beverage and further comprises an aerator, preferably an air pump, for delivering a gas into the beverage liquor. 
     The cooling unit may comprise a liquid coolant. Preferably the liquid coolant comprises propylene glycol and is at a temperature of from −5° C. to −15° C. The cooling unit may be a glycol chiller. One or more coolant pumps may integrated in the cooling unit for circulating coolant around the ice-generating cooling circuit and the pre-chiller cooling circuit. Alternatively, separate pumps may be located along the ice-generating cooling circuit and the pre-chiller cooling circuit. 
     The coolant circulated around the ice-generating cooling circuit may circulated in a primary mode and a secondary mode. Preferably the apparatus is configured such that in the primary mode the coolant is continuously circulated around a primary cooling circuit of the ice-generating cooling circuit which includes the cooling unit and/or in the secondary mode the coolant is continuously circulated around a secondary cooling circuit of the ice-generating cooling circuit which does not include the cooling unit. In contrast, in the prior art system of WO2014/135886 coolant will remain stationary in the cooling conduit  108  when the lower rate of heat transfer is selected since the valve  24  is shut to prevent flow of coolant through the cooling conduit  108 . The method of operation of WO2014/135886 may lead to deleterious effects, for example a new volume of cold coolant may be input into the cooling conduit  108  but not sufficient to fill the entire cooling conduit  108 . This can lead to inconsistent cooling of the liquid  110  in the freeze conduit  3 . Beneficially the apparatus of the present disclosure ensures a more consistent and predictable cooling of the beverage liquor in the product conduit because the temperature of the coolant in the cooling conduit is kept more homogenous throughout the cooling conduit due to the continuous circulation. In addition, the apparatus may avoid the presence of stagnant volumes of relatively warm or relatively cold liquid within cooling circuit which helps to avoid frozen blockages during cooling. Further, the apparatus may beneficially speed up the cooling of the beverage liquor. 
     Preferably the ice-generating cooling circuit may operate in one of the primary mode or secondary mode when switched on. Beneficially this avoids, during operation of the apparatus, a situation where coolant is stationary within the cooling conduit of the ice-generating cooling circuit for any substantial period of time. This may improve the accuracy, speed, homogeneity and consistency of the cooling of the beverage liquor. In addition, if during a maintenance cycle the ice-generating system needs to be heated up to defrost and flush the ice-generating circuit then this may be efficiently carried out by running the ice-generating cooling circuit in the secondary mode which avoids the need to heat up the coolant in the buffer of the cooling unit. 
     The ice-generating system may comprise at least a portion of the product conduit and the cooling conduit which may extend concentrically to one another. Preferably, the cooling conduit surrounds the product conduit. In one example the product conduit may comprise an inner tube that runs within an outer tube. The annular void external to the inner hose and within the outer tube defines the cooling conduit. 
     The concentrically extending product conduit and cooling conduit may be arranged into a spiral configuration. This may beneficially lead to a more compact arrangement of the ice-generating system and may also improve the homogeneity and consistency of the cooling of the beverage liquor. The concentrically extending product conduit and cooling conduit may extend for a length of at least 5 m, preferably at least 10 m. 
     Preferably the product conduit comprises a plastic duct within which the beverage liquor is pumped. Non-limiting examples of suitable materials include PTFE, Nylon, MDPE, EVA, Polyethylene, POM, PVC and mixtures thereof. The plastic surface of the duct reduces ice-crystal nucleation on the duct, encouraging the formation of ice crystals within the beverage liquor and reducing the risk of blockage. In prior art scraped refrigeration devices the ice-crystals tend to grow along the cooled surface walls and form plate-like shards. In contrast, the plastic piping encourages dendritic ice crystal growth from the walls into the flowing channel. Such crystals then get broken off quickly into the flow, where the flow and limited Ostwald ripening encourage more rounded development of the crystals: branches are snapped off or melt away. As a result, the ice crystals which form in the product conduit are smaller and tend to have a tighter, more rounded structure which adds to the longevity of the beverage produced. 
     The cooling conduit may also comprise a plastic duct. Non-limiting examples of suitable materials include PTFE, Nylon, MDPE, EVA, Polyethylene, POM, PVC and mixtures thereof. 
     A controller may be provided to control functions of the apparatus. The controller may comprise hardware and/or software. The controller may comprise a control unit or may be a computer program running on a dedicated or shared computing resource. The controller may comprise a single unit or may be composed of a plurality of sub-units within the apparatus that are operatively connected. The controller may be located on one processing resource or may be distributed across spatially separate computing resources. Separate portions of the apparatus, for example cooling unit, ice-generating system, mixer, etc. may comprise its own sub-controller that is operatively connected to the controller. 
     A product pump may be arranged to circulate the beverage liquor within the product conduit. This product pump may be configured to draw in the beverage liquor into the product conduit from an upstream location or this may require an additional pump or source of compressed gas. As will be appreciated, the apparatus will further comprise the necessary control valves to ensure that the flow is as intended. 
     The beverage concentrate reservoir may contain a volume of beverage concentrate for preparing multiple beverages. Preferably, the source of beverage liquor may comprise an exchangeable supply pack of beverage concentrate. An exchangeable supply pack as defined herein refers to a pack that may be coupled with and decoupled from the apparatus as a means of supplying a volume of beverage concentrate for use by the apparatus. A full pack may be coupled to the apparatus. Coupling may comprise forming a mechanical connection between the pack and the apparatus. Once empty the pack may be decoupled from the apparatus and exchanged for another full pack which may then be coupled to the apparatus to supply further beverage concentrate for use by the apparatus. The pack may be a disposable item or alternatively may be re-fillable. The pack may comprise any suitable container including, but not limited to, a pouch, capsule, cartridge, box, bag-in-box or similar. The pack may be sealed prior to coupling with the apparatus. Means for opening the pack may be integrated in the pack or in the apparatus. The pack may be open automatically during coupling of the pack to the apparatus. A non-limiting example of a suitable pack for use as an exchangeable supply pack is the Promesso® pack. 
     Preferably, a plurality of exchangeable supply packs may be provided containing different types of beverage concentrate. The plurality of exchangeable supply packs may comprise at least a first exchangeable supply pack containing a coffee or tea concentrate and a second exchangeable supply pack containing a freezing-point suppressant, preferably a sweetener concentrate. 
     The mixer may also incorporate into the beverage liquor a diluent, preferably water. 
     The apparatus may be for preparing an aerated ice-containing tea or coffee beverage and may further comprises an aerator, preferably an air pump, for delivering a gas into the beverage liquor. For example, the aerator may comprise a source of pressurised gas arranged to deliver pressurised gas into the beverage liquor before it is cooled. The source of gas may be a gas cylinder containing air or nitrogen under pressure, or may be a compressor, pump or similar for on-demand supply of pressurised air. The gas may be supplied through one or more air inlets within the duct. In a preferred example the aerator is an air pump. 
     The apparatus may further comprise a beverage dispensing outlet for dispensing the flow of beverage liquor as an ice-containing tea or coffee beverage. 
     In some examples the apparatus may further comprise a second beverage dispensing outlet for dispensing another tea or coffee beverage of a different type. The beverage of a different type may be a tea or coffee beverage not containing ice and may optionally be an aerated tea or coffee beverage not containing ice. Both the ice-containing tea or coffee beverage dispensed from the beverage dispensing outlet and the tea or coffee beverage of a different type dispensed from the second beverage dispensing outlet may be derived from the beverage liquor output from the mixing chamber. 
     The or each beverage dispensing outlet may take the form of a conventional beverage nozzle, such as a post-mix style head for ready provision of the final beverage at a bar or beverage counter. 
     The apparatus may form part of a beverage dispensing machine. The beverage dispensing machine may be a point-of-sale unit. The beverage dispensing machine may be a mobile unit. The beverage dispensing machine may be configured to be operated by a barkeeper or similar server or may be configured as a self-serve machine. The beverage dispensing machine may be a vending machine. 
     According to a further aspect there is provided a method for preparing an ice-containing tea or coffee beverage, the method comprising: 
     forming a beverage liquor by mixing a beverage concentrate supplied from a beverage concentrate reservoir with water supplied from a water pre-chiller; 
     circulating the beverage liquor around an ice-generating system to cool the beverage liquor and to thereby form a plurality of ice crystals within the beverage liquor; 
     wherein a single cooling unit is used to circulate a coolant around an ice-generating cooling circuit and a pre-chiller cooling circuit; 
     wherein the ice-generating cooling circuit supplies coolant to the ice-generating system to cool the beverage liquor and the pre-chiller cooling circuit supplies coolant to the water pre-chiller to cool water that is used for mixing with the beverage concentrate. 
     Preferably, a continuous flow of coolant through the ice generating system is maintained in the ice-generating cooling circuit. Optionally, an intermittent flow of coolant to the water pre-chiller is utilised in the pre-chiller cooling circuit. 
     Preferably, the water pre-chiller is also used to cool the beverage concentrate reservoir and/or a mixer for mixing the beverage concentrate with the water. 
     Preferably, the ice-generating cooling circuit is configured to provide coolant to the ice-generating system at a temperature of −1° C. or below and the pre-chiller cooling circuit is configured to provide coolant to the water pre-chiller at a temperature of 2-5° C. 
     As noted above, the beverage liquor may be aerated by the addition of a gas before being cooled in the product conduit. By aerated it is meant that a gas is introduced into the beverage liquor to form a foamed structure containing fine bubbles of the gas. Preferably the gas is air or nitrogen, or another food-grade gas. Air is preferred for convenience. The gas may be introduced by pumping of gas. For example, an air pump may be used to inject air. 
     The gas is preferably added in an amount to achieve an overrun in the final beverage of from 10 to 150%, preferably from 20 to 100%, most preferably from 25 to 75%. Overrun is a standard term in the food and drinks industry to measure the amount of air included in a foamed foodstuff. The overrun may be calculated using the following formula: 
     
       
         
           
             Overrun 
             = 
             
               
                 ( 
                 
                   
                     volume 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     of 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     foamed 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     beverage 
                   
                   - 
                   
                     volume 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     of 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     initial 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     liquid 
                   
                 
                 ) 
               
               / 
               
                   
                 
                   
                     volume 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     of 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     initial 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     liquid 
                   
                   ⋆ 
                   100 
                 
               
             
           
         
       
     
     Preferably the step of aerating the beverage liquor involves inline addition of the gas into a flow of the beverage liquor. That is, the gas is added into a duct containing a flow of the beverage liquor, rather than turbulent mixing of the liquor in a container, for example. The gas is preferably added before the beverage liquor is cooled to form the ice crystals. 
     In order to favour the production of a fine distribution of small bubbles, preferably the inline addition of gas is through a plurality of gas inlet orifices within the duct. Alternatively or in addition, the fine distribution of bubbles can be enhanced by passing the pumped flow of the beverage liquor with the added gas through a static mixer or one or more constricting orifices. The use of constricting orifices may be particularly advantageous because the high pressure jet which is then formed serves to split the bubbles into even finer bubbles which enhance the final beverage creaminess and stability. 
     By way of example, a 1 mm gas injection orifice might produce 5 mm bubbles in the duct. The passing of these bubbles through an orifice of less than 1 mm fractures these bubbles into bubbles smaller than 1 mm each. This fine bubble structure aids the ice stability and the creaminess of the final beverage. 
     The gas is preferably added at a pressure of up to 10 Bar, preferably from 3 to 4 Bar. 
     Forming a plurality of ice crystals within the beverage liquor produces an ice fraction within the beverage liquor. Preferably the ice fraction forms from 10 to 50 wt % of the beverage liquor, preferably from 20 to 30 wt %. This can be measured through the use of a simple cafetiere device used to decant the liquid from the ice-crystals and by determining the relative weights. In practice this may overstate the ice-fraction to a small extent, due to retained water, however, it provides consistently reproduceable and measurable results. 
     The ice-crystals produced in the method preferably have a size ranging from 0.1 to 1 mm, preferably 0.2 to 0.65 mm. Preferably the mean particle size is about 0.25 mm. The size may be measured on a sample using a microscope to measure the longest diameters of each ice crystal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will now be described, by way of example only, in relation to the following non-limiting figures, in which: 
         FIG. 1  shows a diagrammatic view of a prior art apparatus described in WO2014/135886; 
         FIG. 2  shows a schematic view of a prior art apparatus described in WO2018/122277; 
         FIG. 3  shows a perspective view of a beverage preparation machine according to the present disclosure; 
         FIG. 4  shows a flow schematic of a beverage preparation machine according to the present disclosure; 
         FIGS. 5A and 5B  show comparative flow schematics for an ice-generating system of the prior art apparatus of WO2014/135886 and of an apparatus according to the present disclosure; 
         FIGS. 6A, 6B and 6C  show schematic arrangements of portions of apparatus according to the present disclosure; 
         FIGS. 7A and 7B  show alternative flow schematics for a product loop of the apparatus according to the present disclosure; 
         FIG. 8  shows a portion of an apparatus according to the present disclosure; 
         FIG. 9  shows a perspective view of another beverage preparation machine according to the present disclosure; and 
         FIG. 10  shows a flow schematic of the beverage preparation machine of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIG. 3 , the present disclosure provides an apparatus  300  for preparing an ice-containing tea or coffee beverage. In the illustrated example the apparatus  300  takes the form of a mobile point-of-sale unit which may be configured to be operated by a barkeeper or similar server or may be configured as a self-serve machine. 
     The apparatus  300  comprises a main housing  301  which may be configured, for example, as a cabinet that contains components of the apparatus  300 . The main housing  301  may comprise one or more doors, drawers or access panels to allow access to the internal components for purposes of maintenance, restocking of ingredients, etc. The main housing  301  may be provided with castors  302  to render the apparatus  300  mobile. Connections for an external source of power, for example mains electricity, and an external source of water, for example mains water, may also be provided. Alternatively, the apparatus  300  may comprise an internal source of electrical power, for example a battery, and an internal source of water, such as a water reservoir. 
     The apparatus  300  may further comprise a beverage dispensing outlet  303  for dispensing a beverage. In the illustrated example, the beverage dispensing outlet  303  takes the form of a beverage nozzle  304 , such as a post-mix style head, on a font  305  which is mounted to a top surface  306  of the main housing  301 . The top surface  306  may serve as a stand or beverage counter for a receptacle, such as a glass  307 , that receives the dispensed beverage. 
     The apparatus  300  is configured for preparing an ice-containing tea or coffee beverage, preferably an aerated ice-containing tea or coffee beverage.  FIG. 4  illustrates an example of a flow schematic for the apparatus  300  suitable to achieve this configuration. The apparatus  300  may comprise a cooling unit  310 , an ice-generating system  311 , a water pre-chiller  312  and an ingredient source section  313 . 
     The cooling unit  310  comprises a coolant. The coolant may be a liquid coolant. Preferably the liquid coolant comprises propylene glycol and is held in a coolant reservoir within the cooling unit  310  at a temperature of from −5° C. to −15° C. The cooling unit  310  may comprise a compressor unit  316  for maintaining a desired temperature of the coolant in the coolant reservoir. The cooling unit  310  may be a glycol chiller  315 . 
     As shown in  FIG. 4 , the cooling unit  310  may be connected to the ice-generating system  311  by one or more conduits to permit the supply and return of coolant to and from the ice-generating system  311 . A plurality of configurations of conduits may be provided to permit the flow of coolant between the ice-generating system  311  and the cooling unit  310 . Each configuration may be defined as a cooling circuit. Each configuration may be adopted by the actuation of one or more valves to control the conduits through which coolant will flow. 
     A coolant supply conduit  317  may be provided for supplying coolant from the cooling unit  310  to the ice-generating system  311 . A coolant return conduit  318  may be provided for returning coolant from the ice-generating system  311  to the cooling unit  310 . 
     A coolant pump  319  may be provided to pump the coolant between the ice-generating system  311  and the cooling unit  310 . The coolant pump  319  may be integrated in the cooling unit  310  or be a separate pump located along the cooling circuit. Preferably, the coolant pump  319  is located in the coolant supply conduit  317 . 
     A coolant bypass conduit  320  may be arranged to selectively direct coolant from the coolant return conduit  318  into the coolant supply conduit  317  without passing through the cooling unit  310 . The coolant bypass conduit  320  may extend from a first junction  323  with the coolant return conduit  318  which is upstream of the cooling unit  310  to a second junction  324  with the coolant supply conduit  317  which is downstream of the cooling unit  310 . 
     A cooling unit valve  321  may be provided for controlling flow from the coolant return conduit  318  into the cooling unit  310 . The cooling unit valve  321  may be located in the coolant return conduit  318  downstream of the first junction  323 . A coolant bypass conduit valve  322  may be provided for controlling flow through the coolant bypass conduit  320 . The coolant bypass conduit valve  322  may be located in the coolant bypass conduit  320 . In the illustrated example, each of the cooling unit valve  321  and the coolant bypass conduit valve  322  are a two-way valve, for example a solenoid valve. 
     Alternatively, the cooling unit valve  321  and the coolant bypass conduit valve  322  may be substituted for a three-way valve located at the first junction  323  which acts to divert flow of coolant through either the coolant return conduit  318  towards the cooling unit  310  or through the coolant bypass conduit  320  so as to bypass the cooling unit  310 . 
     As shown in  FIG. 4 , the ice-generating system  311  comprises a product conduit  330  for containing a beverage liquor and a cooling conduit  331  which is arranged in proximity with the product conduit  330  to permit heat exchange between coolant in the cooling conduit  331  and beverage liquor in the product conduit  330 . The ice-generating system  311  functions to form a plurality of ice crystals within the beverage liquor as explained further below. 
     The cooling conduit  331  may be fluidly connected to the coolant supply conduit  317  to receive coolant therefrom and also fluidly connected to the coolant return conduit  318  to deliver coolant thereto. 
     Preferably, at least a portion of the product conduit  330  and the cooling conduit  331  extend concentrically to one another. Preferably the cooling conduit  331  surrounds the product conduit  330 . In one example, the product conduit  330  comprises an inner plastic tube that runs within an outer plastic tube. The annular void external to the inner plastic tube and within the outer plastic tube defines the cooling conduit  331 . 
     The product conduit  330  and the cooling conduit  331  may be arranged into a spiral configuration. The product conduit  330  and the cooling conduit  331  may extend for a length of at least 5 m, preferably at least 10 m. The cooling conduit  331  may be split into two or more spiral loops, each loop extending concentrically with a different portion of the product conduit  330 . For example, with a product conduit  330  of 10 m length in a spiral configuration the cooling conduit  331  may be split into two 5 m loops that run concentrically with, respectively, an upper half and a lower half of the product conduit  330 . The coolant may be supplied to the loops of the cooling conduit  331  in parallel or series flow. 
     The conduits of the apparatus  300  may be configured into at least a primary cooling circuit and a secondary cooling circuit. The primary cooling circuit preferably comprises the cooling unit  310 , the coolant supply conduit  317 , the cooling conduit  331  and the coolant return conduit  318 . The secondary cooling circuit preferably comprises the coolant supply conduit  317 , the cooling conduit  331 , the coolant return conduit  318  and the coolant bypass conduit  320  but does not comprise the cooling unit  310 . 
     The apparatus  300  may further comprise a heater  340 , for example a flow through heater, positioned in the primary cooling circuit and/or secondary cooling circuit. In the illustrated example the heater  340  is located in the coolant return conduit  318  so that it is located in a position that is common to both the primary cooling circuit and the secondary cooling circuit. 
     As shown in  FIG. 4 , the water pre-chiller  312  is provided for supplying chilled water to the ingredient source section  313 . The water pre-chiller  312  may contain or be supplied with water. For example, the water pre-chiller  312  may contain a self-contained reservoir, such as a bottle or tank, containing a volume of water that is replenished from time to time by exchanging an empty reservoir for a full reservoir. However, preferably the water pre-chiller  312  is connected to receive water from an external source, such as mains water  347 . A water filter  348  and flow control valve  349  may be provided to condition and control the supply. The water pre-chiller  312  may be any suitable device that can chill the incoming water down to a suitable temperature for supply to the ingredient source section  313 . Preferably the water is chilled to a temperature of 2-5° C. The water pre-chiller  312  may be a phase change material (PCM) cooler or similar device. However, a preferred water pre-chiller  312  is illustrated schematically in  FIGS. 6A to 6C  and utilises flow of coolant from the cooling unit  310 . In this example, the water in the water pre-chiller  312  is cooled by a heat exchanger that is itself cooled by coolant from the cooling unit  310 . The heat exchanger may be either part of the water pre-chiller  312 , or may be in thermal contact with the water pre-chiller  312 . The heat exchanger may comprises one or more blocks for transferring thermal energy. In the example of  FIG. 6A , a first block  350 , preferably of aluminium, comprises a first conduit  353  through which coolant from the cooling unit  210  flows. Multiple first conduits may be provided. A second block  351 , forming part of the water pre-chiller  312  and also preferably of aluminium, comprises a second conduit  354  through which the water in the water pre-chiller  312  flows. Multiple second conduits may be provided. Water in the second conduit  354  is cooled by heat transfer through the second block  351  and the first block  350 . A single integral block may be provided instead of a first block  350  and a second block  352 . The second conduit  354  may take a circuitous route through the second block  351  and/or water may be passed through the second conduit  354  multiple times to be chilled in successive passes. Further, the second conduit  354  may form a reservoir that holds stationary water for chilling as opposed to operating as a flow-through chiller. 
     As shown most clearly in  FIG. 4 , the cooling unit  310  may supply coolant to an ice-generating cooling circuit which supplies coolant from the cooling unit  310  to the ice-generating system  311  and a pre-chiller cooling circuit for supplying coolant from the cooling unit  310  to the water pre-chiller  312 . Beneficially, a single cooling unit  310  can provide the coolant for both the ice-generating cooling circuit and the pre-chiller cooling circuit. 
     The pre-chiller cooling circuit may comprise a secondary coolant supply conduit  376  for supplying coolant from the cooling unit  310  to the water pre-chiller  312 . A secondary coolant return conduit  379  may be provided for returning coolant from the water pre-chiller  312  to the cooling unit  310 . 
     A secondary coolant pump  377  may be provided to pump the coolant between the cooling unit  310  and the water pre-chiller  312 . The secondary coolant pump  377  may be integrated in the cooling unit  310  or be a separate pump located along the secondary cooling circuit. Preferably, the secondary coolant pump  377  is located in the secondary coolant supply conduit  376 . 
     As shown in  FIG. 4 , the ingredient source section  313  comprises a beverage concentrate reservoir  360  containing a beverage concentrate. Preferably, it also comprises a sweetener concentrate reservoir  361  containing a sweetener concentrate. The beverage concentrate contains soluble coffee or tea solids. The sweetener concentrate contains a freezing point suppressant which may be a food-safe soluble ingredient such as a salt, an alcohol, a sugar and/or sugar replacement, ice-structuring proteins or combinations of two or more thereof. It is most preferred that the freezing-point suppressant is itself a sweetener, such as a polyol or a sugar or a mixture thereof. The most preferred freezing point suppressant is sugar or a sugar replacement, preferably sucrose and/or fructose and/or polydextrose. Suitable sugars include mono and disaccharides, preferably, sucrose, fructose, and/or glucose. 
     Optionally, the ingredient source section  313  may comprise two reservoirs containing, preferably, the same ingredient, wherein the apparatus is programmed to switch supply from a first of the two reservoirs to a second of the two reservoirs when the first of the two reservoirs is emptied. In this way a service-ready time of the apparatus may be increased. For example, the reservoir  360  and the reservoir  361  in the example of  FIG. 4  may, optionally, be configured to both contain a same beverage concentrate-sweetener concentrate mix. 
     A first pre-mixer  362  may be provided for mixing the beverage concentrate supplied from the beverage concentrate reservoir  360  with water supplied from the water pre-chiller  312 . Likewise, a second pre-mixer  363  may be provided for mixing the sweetener concentrate supplied from the sweetener concentrate reservoir  361  with water supplied from the water pre-chiller  312 . The water supply to the first pre-mixer  362  and/or the second pre-mixer  363  may be controlled by supply valves  369 . 
     The ingredient source section  313  may further comprise a mixing chamber  364  for mixing an output from the first pre-mixer  362  with an output from the second pre-mixer  363  (where present) to form a beverage liquor. Water may be supplied to the mixing chamber  364  from the water pre-chiller  312  in addition to, or in place of, supplying water to the first pre-mixer  362  and the second pre-mixer  363 . The mixing chamber  364  may comprise an agitator for assisting in the mixing of the beverage liquor and also for recirculating beverage liquor standing in the mixing chamber  364 . The agitator may comprise a rotating blade, paddle, whisk or similar device. Additionally or alternatively, the agitator may comprise a recirculation of the beverage liquor from an output of the mixing chamber  364  back into the mixing chamber  364  to create turbulence and mixing of the beverage liquor within the mixing chamber  364 . A recirculation pump and recirculation conduit may be provided to affect such agitation. 
     The beverage liquor may then be supplied onwards to the ice-generating system  311  as explained further below. 
     The beverage concentrate in the beverage concentrate reservoir  360  may be a powder but is preferably a liquid concentrate. Likewise, the sweetener concentrate in the sweetener concentrate reservoir  361  may be a powder but is preferably a liquid concentrate. 
     The beverage concentrate reservoir  360  and the sweetener concentrate reservoir  361  may each comprise a chamber, hopper or similar that is manually filled with concentrate by an operator, for example by opening a bulk container of concentrate and pouring the concentrate into the chamber or hopper. However, it is preferred that the beverage concentrate reservoir  360  and the sweetener concentrate reservoir  361  each comprise an exchangeable supply pack which may be coupled with and decoupled from the apparatus  300 . The use of exchangeable supply packs may improve the ease and cleanliness of use of the apparatus  300 . Various types of exchangeable supply pack may be used including, but not limited to, a pouch, capsule, cartridge, box, bag-in-box or similar. The exchangeable supply pack may be sealed prior to coupling with the apparatus  300 . Means for opening the exchangeable supply pack may be integrated in the exchangeable supply pack or in the apparatus  300 . The exchangeable supply pack may be opened automatically during coupling of the exchangeable supply pack to the apparatus  300 . A preferred option for the exchangeable supply pack is a Promesso® exchangeable supply pack available from Koninklijke Douwe Egberts B.V. Such an exchangeable supply pack may include a container for holding the concentrate and a doser having an outlet. The doser is arranged for supplying the concentrate from the container to the outlet of the doser in a dosed manner. The doser may include a pump assembly that enables the pumping of a desired dosage of the concentrate from the container out of the outlet and into the pre-mixer  362 ,  363 . 
     The exchangeable supply pack and the apparatus may be mechanically connectable. When connected, the outlet of the doser is brought in fluid communication with the respective pre-mixer  362 ,  363  and a drive shaft (not shown) of the apparatus  300  may be arranged for transmitting torque from the apparatus  300  to the doser such that when the drive shaft is activated concentrate is supplied from the outlet of the doser into the pre-mixer  362 ,  363 . 
     As shown in  FIG. 8 , each pre-mixer  362 ,  363  may be provided with a pre-mixer inlet  370  for receiving concentrate from the doser of the exchangeable supply pack. The pre-mixer inlet  370  may be located towards a top of the pre-mixer  362 ,  363  such that the concentrate may flow from the outlet of the doser into the pre-mixer  362 ,  363  substantially under the influence of gravity. 
     A pre-mixer outlet  372  may be provided for discharging the output into the mixing chamber  364  and a conduit  371  may extend between the pre-mixer inlet  370  and the pre-mixer outlet  372 . Further, each pre-mixer  362 ,  363  may comprise a water inlet opening  373  into the conduit  371  for feeding into the pre-mixer  362 ,  363  water supplied from the water pre-chiller  312 . Preferably, the water inlet opening  373  is orientated to jet inflowing water towards the pre-mixer inlet  370  to thereby flush the outlet of the doser of the exchangeable supply pack, which in use is coupled to the pre-mixer inlet  370 . 
     It is preferred to maintain the beverage concentrate in a chilled state to maintain freshness and improve shelf-life. In order to achieve this, it is preferred that the water pre-chiller  312  and/or the heat exchanger is in thermal contact with the beverage concentrate reservoir  360 . The water pre-chiller  312  and/or the heat exchanger may also beneficially be in thermal contact with the pre-mixer  362  and/or mixing chamber  364 . 
     In one example, the beverage concentrate reservoir  360  is in contact with the first block  350  and/or the second block  351 . Optionally the first block  350  and/or the second block  351  are in face-to-face contact with a face of the beverage concentrate reservoir  360 . The use of exchangeable supply packs that are parallelepiped in shape may be beneficial for this as they provide a relatively large surface area to make contact with the first block  350  and/or the second block  351 . In the arrangement of  FIG. 6A , a beverage concentrate reservoir  360  in the form of an exchangeable supply pack C is positioned alongside, and in thermal contact with, the water pre-chiller  312 , in particular the second block  351  thereof. A side face of the exchangeable supply pack C is preferably in face-to-face contact with a side face of the second block  351 . In the alternative arrangement of  FIG. 6B , the exchangeable supply pack C is positioned above, and in thermal contact with, the water pre-chiller  312 , in particular the first block  350  thereof. A bottom face of the exchangeable supply pack C is preferably in face-to-face contact with a top face of the first block  350 . In the further alternative arrangement of  FIG. 6C , the exchangeable supply pack C is positioned above, and in thermal contact with, the water pre-chiller  312 , in particular the second block  351  thereof. A bottom face of the exchangeable supply pack C is preferably in face-to-face contact with a top face of the second block  351 . 
     Preferably, the sweetener concentrate reservoir  361  is thermally isolated from the water pre-chiller  312  and/or heat exchanger. This may be beneficial to prevent crystallisation of the ingredients of the sweetener concentrate. Preferably the temperature of the sweetener concentrate reservoir  361  is maintained at greater than 10° C. For example, in the arrangements of  FIG. 6A to 6C , the sweetener concentrate reservoir  361  in the form of an exchangeable supply pack S is separated from, i.e. out of thermal contact with, the water pre-chiller  312 . Optionally, thermal insulation material may be interposed between the sweetener concentrate reservoir  361  and the water pre-chiller  312 . 
     An output  380  of the mixing chamber  364  may supply the beverage liquor to the ice-generating system  311  via a conduit and one or more product supply valves  366   a ,  366   b . The beverage liquor is preferably aerated prior to reaching the ice-generating system  311 . An air pump  367  may inject air under control of an air supply valve  368  into the conduit containing the beverage liquor before it reaches the one of more product supply valves  366   a ,  366   b . The air may be injected through one or more gas injection orifices. In order to favour the production of a fine distribution of small bubbles the flow of the beverage liquor with the added gas may be pumped through a static mixer or one or more constricting orifices. By way of example, a 1 mm gas injection orifice might produce 5 mm bubbles in the conduit. The passing of these bubbles through an orifice of less than 1 mm fractures these bubbles into bubbles smaller than 1 mm each. This fine bubble structure aids the ice stability and the creaminess of the final beverage. The air is preferably added at a pressure of up to 10 Bar, preferably from 3 to 4 Bar. The beverage liquor may be pumped out of the mixing chamber  364  and through the product supply valves  366   a ,  366   b  by means of an upstream product pump  365  as shown in  FIG. 4 . 
     The one or more product supply valves  366   a ,  366   b  may connect to the product conduit  330  of the ice-generating system  311 . The one or more product supply valves  366   a ,  366   b  may comprise a first product supply valve  366   a  and a second product supply valve  366   b . The product conduit  330  may form a loop to allow the beverage liquor to circulate. Beverage liquor may be input into the product conduit  330  through one or more beverage liquor inlets. A first beverage liquor inlet  394  may be provided which may be connected to the first product supply valve  366   a  by a first product supply conduit  375   a . A second beverage liquor inlet  395  may be provided which may be connected to the second product supply valve  366   b  by a second product supply conduit  375   b.    
     Beverage liquor containing the plurality of ice crystals may be discharged from the product conduit  330  through an outlet  393  that supplies the beverage dispensing outlet  303 . Preferably, only a single outlet  393  is provided. Preferably, the volume and/or pressure of the beverage liquor within the product conduit  330  is maintained within set limits, and preferably substantially constant and preferably at around 2 bar. This may be achieved by ensuring that the total volume of beverage liquor input to the product conduit  330  through the one or more beverage liquor inlets  394 ,  395  equals the volume of the beverage liquor discharged through the outlet  393 . 
     The product conduit  330  comprises a primary product pump  390  for circulating the beverage liquor around the product conduit  330 . An upstream pressure sensor  391  and a downstream pressure sensor  392 , as shown in  FIGS. 7A and 7B , may be located on either side of the primary product pump  390  to sense the differential pressure across the primary product pump  390 . This differential pressure may be used to calculate, infer or estimate the ice/liquid ratio of the beverage liquor. 
       FIG. 7A  illustrates an example where only a first beverage liquor inlet  394  is provided. A quantity of relatively warm beverage liquor  397  is input through first beverage liquor inlet  394  and is circulated clockwise (as viewed in  FIG. 7A ) at the same time as already present and relatively cold beverage liquor  396  containing a plurality of ice crystals is discharged through the outlet  393 . As the relatively warm beverage liquor  397  passes the primary product pump  390  a change in the differential pressure between the upstream pressure sensor  391  and the downstream pressure sensor  392  is detected by the controller which acts to increase the rate of cooling of the product conduit  330 , as discussed further below, to cool the relatively warm beverage liquor  397  to form the desired ice/water ratio. 
     A potential disadvantage of the arrangement of  FIG. 7A  is that frozen blockages may occur where the increased rate of cooling commanded by the controller imparts further cooling to the relatively cold beverage liquor  396  still circulating in the product conduit  330 . 
     Thus,  FIG. 7B  presents an improved arrangement wherein at least the first beverage liquor inlet  394  and the second beverage liquor inlet  395  are used. The first beverage liquor inlet  394  and the second beverage liquor inlet  395  are distributed along the product conduit  330 . For example, the loop of the product conduit  330  may be considered to have a length of X, and the second beverage liquor inlet  395  may be located between 0.4X and 0.6X along the loop of the product conduit  330  from the first beverage liquor inlet  394 . For example, in the case of a product conduit  330  of length X=10 m the second beverage liquor inlet  395  would be located between 4 m (10 m×0.4) and 6 m (10 m×0.6) along the loop of the product conduit  330  from the first beverage liquor inlet  394 . More preferably, the second beverage liquor inlet  395  may be located halfway around the loop of the product conduit  330  from the first beverage liquor inlet  394 , i.e. at 0.5X. Optionally, third and/or fourth, etc. beverage liquor inlets may be provided. These may preferably be evenly distributed around the loop of the product conduit  330 , i.e. at 0X, 0.33X and 0.67X where three beverage liquor inlets are provided; at 0X, 0.25X. 0.50X and 0.75 X where four beverage liquor inlets are provided, etc. 
     Inputting the relatively warm beverage liquor  397  through at least two beverage liquor inlets is beneficial as it provides a more even distribution of the relatively warm beverage liquor  397  in the relatively cold beverage liquor  396  as shown schematically in  FIG. 7B . This may help or reduce or eliminate frozen blockages occurring. Further benefit can be achieved by configuring and arranging for the input of beverage liquor into the product conduit  330  to be alternated, preferably relatively quickly, between the at least two beverage liquor inlets such that ‘chunks’ of relatively warm beverage liquor  397  are input into the flow of relatively cold beverage liquor  396  such that each chunk is bounded on either side by relatively cold beverage liquor  396 . This may beneficially create an even more even distribution of the relatively warm beverage liquor  397  in the relatively cold beverage liquor  396 . This may reduce or eliminate frozen blockages occurring. In addition, using this arrangement may mean that the controller does not need to switch rapidly from an aggressive cooling mode to a non-cooling mode. Further the proximity of the relatively cold beverage liquor  396  to the relatively small volume of each chunk of relatively warm beverage liquor  397  helps to cool more efficiently the relatively warm beverage liquor  397 . 
     This configuration may be achieved by arranging the first product supply valve  366   a  for controlling flow of beverage liquor to the first beverage liquor inlet  394  and the second product supply valve  366   b  for controlling flow of beverage liquor to the second beverage liquor inlet  395  as noted above. Further, the controller may be configured and arranged to control actuation of the first product supply valve  366   a  and the second product supply valve  366   b  to alternate the input of beverage liquor into the product conduit  330  through the first product supply valve  366   a  and the second product supply valve  366   b  by cycling the first product supply valve  366   a  and the second product supply valve  366   b  between a first configuration where the first product supply valve  366   a  is open and the second product supply valve  366   b  is closed and a second configuration where the first product supply valve  366   a  is closed and the second product supply valve  366   b  is open. Preferably the cycle time may be such as to obtain a valve open time of 0.3 to 0.8 seconds, preferably 0.4 to 0.6 seconds, more preferably 0.5 seconds for each cycle. Preferably, the cycling of the first product supply valve  366   a  and the second product supply valve  366   b  includes an overlap period in each cycle where both the first product supply valve  366   a  and the second product supply valve  366   b  are open to help ensure a constant inflow into the product conduit  330 . 
     A non-limiting example of use of the apparatus  300  will now be described. A beverage concentrate reservoir  360  in the form of a Promesso® exchangeable supply pack containing a beverage concentrate containing soluble coffee solids and a sweetener concentrate reservoir  361  in the form of a Promesso® exchangeable supply pack containing a sweetener concentrate are installed in the apparatus  300 , mechanically coupled to the respective first pre-mixer  362  and second pre-mixer  363 . 
     Water supplied to the water pre-chiller  312  is chilled to a temperature of 2-5° C. by coolant flowing through the pre-chiller cooling circuit, in particular wherein coolant is pumped by the secondary coolant pump  377  from the cooling unit  310  along the secondary coolant supply conduit  376 , through the first conduit  353  of the heat exchanger and then back to the cooling unit  310  along secondary coolant return conduit  379 . Flow of the coolant around the pre-chiller cooling circuit is controlled by the controller. As will be appreciated by those skilled in the art, sensors and/or meters, for example flow meters and temperature sensors, may be provided to provide the necessary data inputs to the controller to permit flow and/or temperature control of the pre-chiller cooling circuit to be achieved. 
     When demanded by the controller, a dose of beverage concentrate is dosed from the beverage concentrate reservoir  360  into the first pre-mixer  362  through the pre-mixer inlet  370  where it is mixed and diluted with water that is injected through the water inlet opening  373 . This water is supplied from the water pre-chiller  312  by the controller opening the respective supply valve  369 . The diluted beverage concentrate passes along the conduit  371  and is discharged through the pre-mixer outlet  372  into the mixing chamber  364 . 
     If required by the beverage being dispensed, a dose of sweetener concentrate may also be dosed, preferably simultaneously, from the sweetener concentrate reservoir  361  into the second pre-mixer  363  through the pre-mixer inlet  370  where it is mixed and diluted with water that is injected through the water inlet opening  373 . As above, this water is supplied from the water pre-chiller  312  by the controller opening the respective supply valve  369 . The diluted sweetener concentrate passes along the conduit  371  and is discharged through the pre-mixer outlet  372  into the mixing chamber  364 . 
     The diluted beverage and sweetener concentrates are mixed together in the mixing chamber  364  by the agitator to form the beverage liquor. 
     When demanded by the controller, beverage liquor from the mixing chamber  364  is supplied to the ice-generating system  311  through the first product supply conduit  375   a  and the second product supply conduit  375   b  by operation of the first product supply valve  366   a  and the second product supply valve  366   b.  The beverage liquor is aerated prior to reaching the ice-generating system  311 . The air pump  367  injects air under control of the air supply valve  368  into the conduit containing the beverage liquor before it reaches the first product supply valve  366   a  and the second product supply valve  366   b.    
     As illustrated schematically in  FIG. 7B , the controller controls actuation of the first product supply valve  366   a  and the second product supply valve  366   b  to alternate the input of beverage liquor into the product conduit  330  through the first product supply valve  366   a  and the second product supply valve  366   b  by cycling the first product supply valve  366   a  and the second product supply valve  366   b  between the first configuration and the second configuration with a cycle time of 0.3 to 0.8 seconds, preferably 0.4 to 0.6 seconds, more preferably 0.5 seconds for each cycle. Preferably, the cycling of the first product supply valve  366   a  and the second product supply valve  366   b  includes an overlap period in each cycle where both the first product supply valve  366   a  and the second product supply valve  366   b  are open to help ensure a constant inflow into the product conduit  330 . Consequently, the beverage liquor is input into the product conduit  330  from at least two locations as ‘chunks’ of relatively warm beverage liquor  397  such that each chunk is bounded on either side by relatively cold beverage liquor  396 . 
     The relatively warm beverage liquor  397  circulates in the product conduit  330  where it is cooled by the coolant flowing in the cooling conduit  331  and preferably also by the already present relatively cold beverage liquor  396  to form a plurality of ice crystals in the aerated beverage liquor. 
     Simultaneously, aerated beverage liquor that already contains a plurality of ice crystals is discharged out of the product conduit  330  through the single outlet  393  onwards to the beverage dispensing outlet  303  where it is dispensed into the glass  307 . 
     As shown in  FIG. 5B , the coolant flowing in the cooling conduit  331  may be in a direction that opposes the flow of beverage liquor in the product conduit  330 . 
     When active cooling of the beverage liquor in the product conduit  330  is required—for example, because the ice/water ratio as sensed by the upstream pressure sensor  391  and downstream pressure sensor  392  is not at a desired level—the controller switches the ice-generating system  311  to the primary mode wherein the coolant is circulated around the cooling unit  310 , the coolant supply conduit  317 , the cooling conduit  331  and the coolant return conduit  318 . By passing the coolant through the cooling unit  310  in the primary mode the coolant is cooled and so active cooling of the beverage liquor is achieved. Beneficially, in the primary mode coolant may flow continuously around the primary cooling circuit and is not required to become stationary. 
     When active cooling of the beverage liquor in the product conduit  330  is not required—for example, because the ice/water ratio as sensed by the upstream pressure sensor  391  and downstream pressure sensor  392  is at the desired level—the controller switches the ice-generating system  311  to the secondary mode wherein the coolant is circulated around the secondary cooling circuit comprising the coolant supply conduit  317 , the cooling conduit  331 , the coolant return conduit  318  and the coolant bypass conduit  320 . In particular, the secondary cooling circuit does not comprise the cooling unit  310  so the coolant is not subjected to any additional cooling. This allows the coolant to gradually warm up as it circulates around the secondary cooling loop. Beneficially, in the secondary mode coolant may flow continuously around the secondary cooling circuit and is not required to become stationary. 
     This method is in contrast to the prior art arrangement of WO2014/135886, shown schematically in  FIG. 5B . In that arrangement, when active cooling of the beverage liquor in the cooling conduit  108  is not required the valve  24  is shut to prevent flow of coolant through cooling conduit  108 . Valve  23  is opened to circulate the coolant via the coolant bypass loop and through the coolant refrigeration unit  22  using pump  19 . However, coolant in the cooling conduit  108  remains stationary. 
     Thus, the present apparatus  300 , system and method permit the preparation of an ice-containing tea or coffee beverage, which is also preferably aerated. The appearance of the beverage which is produced will depend on the ice-fraction and the overrun of the beverage. A beverage with a high overrun, such as 100% and a low ice-fraction, such as 10 to 20%, may resemble a homogeneous light brown foam and may retain this form and stability for upward of 10 minutes. In practice the ice is well insulated and melts slowly. Eventually an underlying coffee or tea layer may form, but this may typically take at least 30 minutes. Preferably no separate water layer forms, as would be seen in a beverage made from coarse ice-crystals. In a beverage with coarser ice-crystals, these typically migrate to the top as they are least dense and then melt without the beverage solids being present. 
     A beverage with a lower overrun, such as 25% and with a higher ice fraction, such as 30%, may form an initial thicker foam layer on a darker beverage layer. However, the whole structure will have an even distribution of ice and will not form a separate water layer. Instead it may resemble, albeit with less separation, the classic beverage Guinness® appearance of a dark liquor with a foamed head and demonstrates a storm-cloud settling effect. The foam persists in part because it is stabilised by the fine ice-crystals distributed therein. 
       FIG. 9  illustrates a further embodiment of apparatus  300  according to the present disclosure. In the following description only the differences between this embodiment and the preceding embodiments will be described. It will be understood by the skilled reader that in all other respects the apparatus  300  may be configured and function as described above in the preceding embodiments. 
     As in the previous embodiments the apparatus  300  of  FIG. 9  may take the form of a mobile point-of-sale unit which may be configured to be operated by a barkeeper or similar server or may be configured as a self-serve machine. The apparatus  300  may comprise a first beverage dispensing outlet  303   a  for dispensing a first beverage and a second dispensing outlet  303   b  for dispensing a second beverage. In the illustrated example, the beverage dispensing outlets  303   a ,  303   b  each take the form of a beverage nozzle  304   a,    304   b,  such as a post-mix style head. The beverage dispensing outlets  303   a,    303   b  may both be provided for example on a single font or, as illustrated in  FIG. 9 , separately on two fonts  305   a,    305   b  each of which is mounted to the top surface  306  of the main housing  301 . 
     The apparatus  300  may be configured for preparing an ice-containing tea or coffee beverage, preferably an aerated ice-containing tea or coffee beverage, which may be dispensed via the first beverage dispensing outlet  303   a.  The apparatus  300  may in addition be configured for preparing another beverage of a different type which may be dispensed via the second beverage dispensing outlet  303   b.  The beverage of the different type may be for example a beverage not containing ice, for example a tea or coffee beverage not containing ice. The beverage of the different type may for example be an aerated tea or coffee beverage and preferably a cooled and aerated tea or coffee beverage. 
       FIG. 10  illustrates an example of a flow schematic for the apparatus  300  suitable to achieve this configuration. The flow schematic is the same as that of  FIG. 4  except for the following points. 
     The beverage supplied to the second beverage dispensing outlet  303   b  by-passes the ice-generating system  311  such that ice crystals are not formed in the beverage prior to dispensation. Instead the beverage may consist of or comprise the beverage liquor that is output from the mixing chamber  364 . As shown in  FIG. 10 , an additional product supply valve  366   c  may be provided to selectively direct the beverage liquor to the second dispensing outlet  303   b  via a beverage conduit  398 . As in the above embodiments, this beverage liquor may optionally be aerated by the air pump  367 . The upstream product pump  365  may drive the flow of beverage liquor to the second beverage dispensing outlet  303   b.    
     In operation of the apparatus  300  an ice-containing beverage may be dispensed from the first beverage dispensing outlet  303   a  and a non-ice-containing beverage may be dispensed from the second beverage dispensing outlet  303   b.  Advantageously, the same beverage liquor output from the mixing chamber  364  may be used to supply both beverage dispensing outlets  303   a,    303   b.    
     The apparatus  300  may additionally or alternatively be adapted compared to the preceding embodiments by maintaining the sweetener concentrate reservoir  361  in a chilled state within the apparatus  300 . It has been found that chilling of the sweetener concentrate reservoir  361  is not always required to prevent ice crystallisation, in particular in situations where the expected usage rate of the sweetener concentrate means that the sweetener concentrate reservoir  361  will be replaced every 5 to 10 days. Advantageously chilling the sweetener concentrate reservoir  361  can provide improved efficiency when cooling the resulting beverage liquor containing the sweetener concentrate, reduce the risk of microbial growth and reduce the length of conduits required to connect the sweetener concentrate reservoir  361  to a remainder of the apparatus  300 . Further, maintaining both the beverage concentrate reservoir  360  and the sweetener concentrate reservoir  361  in a chilled state may allow a simplified component layout within the housing  301 . For example, a separate uncooled chamber is not required for the sweetener concentrate reservoir  361  and both reservoirs  360 ,  361  can be stored in the same compartment. 
     In a first example configuration the sweetener concentrate reservoir  361  may be placed in thermal contact with the water pre-chiller  312  and/or the heat exchanger and/or the beverage concentrate reservoir  360 . For example, the sweetener concentrate reservoir  361  in the form of the exchangeable supply pack S may be positioned alongside, and in thermal contact with, the water pre-chiller  312 , in particular the first block  350  and/or second block  351  thereof. 
     In a second example configuration the beverage concentrate reservoir  360  and the sweetener concentrate reservoir  361  may be placed in a refrigerated compartment of the apparatus. The refrigerated compartment may be cooled by the water pre-chiller  312  and/or the heat exchanger and/or by another refrigeration means. 
     Although preferred embodiments of the present disclosure have been described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the scope of the appended claims.