Patent Publication Number: US-2021186258-A1

Title: Method for adjusting the dispensing temperature of a caffeinated hot beverage and automatic beverage maker for preparing a caffeinated hot beverage having a specified dispensing temperature

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a United States National Stage Application of International Application No. PCT/EP2019/062581 filed May 16, 2019, claiming priority from German Patent Application No. 10 2018 111 881.3 filed May 17, 2018. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a method for adjusting the dispensing temperature of a hot beverage and an automatic beverage maker for preparing a hot beverage with a defined dispensing temperature. 
     BACKGROUND 
     Chilled hot beverages with a lower temperature than a brewing temperature are enjoying increasing popularity. The fully automatic production of this type of product is therefore of great interest both for automatic beverage makers for domestic use, e.g. coffee makers, and in particular for automatic beverage makers, especially so-called fully automatic coffee makers for commercial use in bars, cafés, bakeries and the like. 
     Conventional methods of cold extraction, such as Cold Drip or Cold Brew, are not practical for a fully automatic coffee maker due to the time required, and with the vast majority of known alternative systems or processes, such as disclosed in EP 2 268 175 B1, hot brewed coffee is cooled to a temperature below the brewing temperature exclusively indirectly through the use of heat exchangers. 
     The range of action of this procedure is severely limited by the dependence on ambient temperatures, coffee quantities, flow speeds and heat transfer surfaces, so that the coffee output temperature is only a result of these factors and cannot be individually produced and adjusted. 
     EP 2 238 876 A2 describes an automatic beverage maker with a device for the direct introduction of cold water into the coffee, wherein the cold water quantity is controlled by determining the concentration. 
     According to WO 2015/149899 A1, the coffee beverage is first cooled in a heat exchanger. Then cold water can be added to the coffee beverage flowing to the coffee spout via a controllable valve. The valve is controlled by determining the flow rate using a flow meter which can be positioned along the cold water supply lines. 
     DE 10 2011 076 214 A1 is mentioned as the generic prior art. A pump is used to add cold water, which results in a relatively poor controllability of the metering process. 
     SUMMARY OF THE INVENTION 
     Based on the aforementioned prior art, it is an object of the present invention to provide an improved, in particular simple and precise, method for adjusting the dispensing temperature of a hot beverage, such as a caffeinated hot beverage. 
     The present invention solves the above and other objects by provision of a method for adjusting a dispensing temperature of a hot beverage, such as a caffeinated beverage, by an automatic beverage maker as described below and by an automatic beverage maker which may be used for implementing the method as also described below Although the invention is described below in the context of preparing a caffeinated hot beverage, it is obvious that the invention is equally applicable to the preparations of a non-caffeinated hot beverage. 
     A method according to the invention is suitable for adjusting the dispensing temperature of a caffeinated hot beverage by an automatic beverage maker, preferably by a hot beverage maker, in particular by a fully automatic coffee maker. The method can optionally also be used for the preparation of the caffeinated hot beverage, since it comprises all essential preparation steps. 
     In particular, the hot beverage is a hot beverage containing coffee and/or espresso. The automatic beverage maker can also be designed as a so-called piston machine. The actual method then comprises at least the following steps: 
     In a first step, hot water is provided by a boiler. The water supplied is heated inside the boiler to temperatures preferably above 75° C., and especially preferably from 80° C. to 96° C. Water at this temperature is also referred to as hot water in this document. 
     In a further step, the caffeinated hot beverage is prepared by a brewing unit. The brewing unit is supplied with either hot water directly from the boiler or optionally with already cooled hot water, e.g. between 50° C. and 75° C. 
     In a further step, the temperature of the caffeinated hot beverage is measured. The measurement can preferably be carried out directly at the outlet of the brewing unit or preferably after the cold water has been added and especially after a further optional cooling, e.g. indirect aftercooling. 
     The measured temperature is then preferably compared with at least one desired value. This at least one desired value can be, for example, a predetermined value for the output temperature of the hot beverage to be achieved. However, the temperature to be achieved, in particular the dispensing temperature immediately before the caffeinated hot beverage is dispensed by a dispensing unit, i.e. after various cooling measures, can also be assumed as the desired value. 
     The temperature of the caffeinated hot beverage can then be controlled and/or regulated to adjust to the desired value by cooling. Cooling can include a machine-controlled first or further addition of cold water to the caffeinated hot beverage provided by the brewing unit. Alternatively, or additionally, the hot water supplied to the brewing unit can also be cooled by a machine-controlled cold water addition before it is fed into the brewing unit. In this respect, machine-controlled cold water addition means that it is controlled or regulated by the machine and is thus initiated, either by a pipe inside the machine through which the water for preparing the hot beverage flows or through which the already prepared hot beverage flows, or by a separate outlet directly into the vessel into which the prepared hot beverage is dispensed. In this case the temperature is adjusted to the desired value at least partially by means of a cold water quantity supplied by the cold water addition as a liquid medium by means of the machine-controlled cold water addition, wherein the adjustment or adaptation of the temperature is effected by metering (dosing) the cold water quantity, wherein a controllable metering valve is used for metering. 
     Compared to the prior art, this makes it possible to add precisely metered cold water from a tank or from a pipe or the like in a simple way, without a pump for cold water addition being absolutely necessary in the machine. 
     “At least partly” means in this context that for the adjustment of the temperature, in addition to the supply of cold water, further possibilities of cooling may be provided, e.g. by a heat exchanger within the scope of indirect aftercooling, or by pre-cooling the supplied cold water. 
     Recording the temperature of the cooled caffeinated hot beverage, but also of the metered cold water and a dosage of cold water enables an exact setting of the dispensed coffee temperature. This allows, among other things, individual recipes for hot beverages, which can be specifically adjusted to the user, the dispensing point or a chain of companies on site. 
     Automatic beverage makers in the sense of the present invention are both automatic beverage makers for domestic use, e.g. coffee makers, but also in particular automatic beverage makers, in particular so-called fully automatic coffee makers for commercial use in bars, cafés, bakeries and the like. 
     The automatic beverage maker may, in particular, include several data records comprising at least the dispensing quantity and the dispensing temperature as a function of a selected type of hot beverage. Thus, the quantity and the temperature can be prepared individually for each product by selecting the type of beverage. 
     This means that the same quantity is not always cooled to the same temperature, but rather the dispensed beverage can be produced individually for each product in order to maintain a particularly high product variety. 
     The temperature of the caffeinated hot beverage can be advantageously measured after the addition of cold water, wherein the amount of cold water supplied is controlled depending on this measuring signal. Thus, a very direct check and adjustment of the product temperature is achieved preferably immediately before its dispensing. 
     For the purposes of the present invention, a control and/or regulation as a function of individual measured variables is always to be understood in the sense that the aforementioned control and/or regulation can be carried out exclusively on the basis of this measured variable, but it is also possible that the control and/or regulation can be influenced by several measured variables, e.g. temperatures or flow rates. For example, with reference to the aforementioned temperature of the caffeinated hot beverage, the volume of the hot beverage can also be included in the control of the cold water quantity and, optionally, also in the temperature of the cold water when it is fed in as part of a pre-cooling of the cold water by measuring a volume and/or mass flow rate. 
     The caffeinated hot beverage can be prepared in the brewing unit, with cold water being supplied after the brewing unit. The brewing speed is known to be dependent on the temperature. It is therefore advisable to brew a large number of beverages at a brewing temperature of over 75° C. and only then to cool them down by supplying cold water. 
     Alternatively, or additionally, cold water can be supplied before the brewing unit as part of a particularly gentle preparation process. 
     The cold water supplied can be additionally cooled internally in the machine by a first cooling device, so that the cold water supplied to the hot beverage can be colder than the water supplied to the automatic beverage maker. Peltier cooling and/or indirect cooling is may be used for cold water cooling. 
     The temperature of the cold water can be determined before it is added to the caffeinated hot beverage or to the water supplied to a brewing unit for the production of the caffeinated hot beverage, and the control of the amount of cold water added can be carried out as a function of the temperature determined. This option offers a more advanced and even more precise metering of the cold water. 
     The caffeinated hot beverage can also be cooled in a second cooling device after the addition of cold water in order to achieve a final temperature. It is clear that the addition of cold water changes the strength or concentration of the hot beverage. Therefore, in the case of some beverages, the metering of cold water can only be carried out up to an upper limit of cold water. The target temperature for dispensing the hot beverage can also be set in this case by the second cooling device, which can be designed as a heat exchanger. It is understood that any other beverage can also be fine-tuned with regard to temperature by means of aftercooling, provided that this is not already achieved via the cold water supply. 
     The measurement of the temperature of the caffeinated hot beverage in accordance with the invention can be carried out after adding cold water and passing the caffeinated hot beverage through that of the second cooling device. 
     Alternatively, or in addition, the temperature of the caffeinated hot beverage can also be measured before adding cold water. 
     It may be energy-saving, constructively advantageous and water-saving, if part of the cold water, especially the cooled cooling water, can be used to operate the second cooling device. 
     In addition, the part of the cold water for operating the second cooling device can be partially or completely returned to the cold water upstream of the first cooling device. 
     The throttle valve is used to precisely adjust the temperature by metering the cold water flow. An electrically adjustable throttle valve which limits the flow rate, especially an electrically adjustable motor-driven throttle valve which limits the flow rate may be used as a throttle valve. It is understood that the valve can also be mass-flow limited. If the viscosity is known, the conversion is possible without further ado. 
     It is also possible to homogenize a mixture of the caffeinated hot beverage and cold water before measuring the temperature, especially by using a homogenizer, to ensure optimal thorough mixing and heat energy transfer. 
     As already mentioned above, the desired value for the metering of the cold water, the pre-cooling of the cold water and especially the target temperature after aftercooling at the outlet can be assigned product-specifically by a second cooling device, according to the product selected by the user. For this purpose, in a manner known per se, the automatic beverage maker can have a control and/or evaluation unit with a CPU and a data memory, wherein corresponding product-specific data records, e.g. temperatures, volumes, etc., are stored on the data memory at various points in the process or in the automatic beverage maker. These data records can also be device-specific at the same time, depending on the device type. 
     It is also be possible to continuously correct the mixing temperature during the brewing process when preparing the caffeinated hot beverage. This can be carried out, for example, by measuring the temperature after aftercooling and making a corresponding readjustment after an actual/desired value adjustment. 
     The hot water volume and/or mass flow supplied to the brewing unit and the cold water volume and/or mass flow can be determined to optimize the discharge characteristics. 
     Cooling, both direct cooling and aftercooling, can be carried out using temperature curves and/or profiles, i.e. temperature measurement taking into account the course of time. Corresponding temperature curves and/or profiles can be stored as desired value data records. 
     The cold water can be supplied to the second cooling device before being supplied directly into the caffeinated hot beverage or into the water supplied to the brewing unit for the production of the caffeinated hot beverage in an indirect cooling of the caffeinated hot beverage with supplied cold water quantity. 
     The automatic beverage maker can have at least two operating modes, wherein in a first operating mode the cooling of the caffeinated hot beverage or of the water supplied to the brewing unit for the production of the caffeinated hot beverage is effected directly by means of a machine-controlled addition of cold water, and wherein in a second operating mode a caffeinated hot beverage is dispensed without cooling by machine-controlled addition of cold water. Thus, the automatic beverage maker can be used variably for hot beverages and cooled hot beverages. 
     Cooling of the caffeinated hot beverage or the water supplied to the brewing unit for the production of the caffeinated hot beverage by direct supply via a machine-controlled addition of cold water can be carried out after indirect further cooling of the cold water supplied from outside for the cold water addition, which is carried out internally within the machine. 
     The supply of cold water as direct cooling can be carried out after direct or indirect (further machine-internal) cooling of the cold water, in particular by the first cooling device, or before indirect cooling of the caffeinated hot beverage, in particular by the second cooling device. 
     An automatic beverage maker according to the invention for the preparation of a caffeinated hot beverage may be designed to carry out a method according to the invention. The caffeinated hot beverage is dispensed in particular with a defined dispensing temperature. The temperature can be measured and adjusted to a specified desired value. The desired value can be set by the user, for example, or specified according to the type of beverage selected by the user. 
     Such an automatic beverage maker may comprise a water inlet, a hot water line and a cold water line, a boiler for heating and/or providing hot water in the hot water line, a brewing unit for providing the caffeinated hot beverage in the hot water line and a dispensing device at the end of the hot water line for dispensing the caffeinated hot beverage from the automatic beverage maker. The hot water line has a cold water supply line for feeding cold water into the hot water upstream of the brewing unit or for feeding cold water into the prepared caffeinated hot beverage, wherein the automatic beverage maker may have a temperature sensor for determining a temperature of the caffeinated hot beverage after it has been prepared by the brewing unit for determining the temperature in or directly upstream of the dispensing unit, wherein the cold water is added as a function of the temperature determined by the temperature sensor. 
     In this context, direct means that there is no longer any direct and/or indirect cooling of the hot beverage between the temperature sensor and the dispensing unit, apart from the usual unwanted heat loss in the pipes. 
     By placing the temperature sensor in the area of the dispensing unit, a very precise temperature adjustment is possible, e.g. by readjusting individual cooling systems, e.g. direct cooling or indirect cooling. 
     The automatic beverage maker can be equipped with a homogenizer, which is arranged downstream of the cold water supply line. 
     Furthermore, the automatic beverage maker can have a second cooling device for indirect cooling of the caffeinated hot beverage, which is arranged downstream of the cold water supply line, and possibly downstream of the homogenizer. 
     Furthermore, the automatic beverage maker can be equipped with a first cooling device for pre-cooling the cold water before it is fed into the hot water upstream of the brewing unit or for feeding cold water into the caffeinated hot beverage. 
     In addition to the temperature sensor for determining a temperature of the caffeinated hot beverage in or immediately in front of the dispensing unit, the automatic beverage maker can have a temperature sensor for adjusting the cold water temperature by the first cooling device. 
     In addition or as an alternative to the above-mentioned temperature sensor for cold water temperature adjustment, the automatic beverage maker can also have a temperature sensor for determining the temperature of the prepared uncooled caffeinated hot beverage, which is arranged downstream of the brewing unit and upstream of a cooling supply line for feeding cold water into the prepared caffeinated hot beverage. 
     The automatic beverage maker may have a flow meter which is arranged in the hot water line. This can be used to determine the amount of water supplied to the boiler and/or the brewing unit. 
     The automatic beverage maker can additionally or alternatively have a flow meter, which is located in the cold water line. This can be used to determine the quantity of cold water supplied to the second cooling device and/or the quantity of cold water supplied to the hot water upstream of the brewing unit or to supply cold water to the caffeinated hot beverage. 
     The flow of cold water within the automatic beverage maker can be implemented so that the cold water can be pre-cooled by the first cooling device, can be fed to the second cooling device as a cooling medium for aftercooling the caffeinated hot beverage to which cold water has been applied and can then be introduced into an uncooled caffeinated hot beverage. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       In the following, the invention is explained in more detail in several embodiments on the basis of the accompanying figures, wherein the invention is not limited to the concretely represented embodiments, wherein: 
         FIG. 1  shows a schematic representation of a first embodiment of an automatic beverage maker according to the invention with regulated cold water supply into a caffeinated hot beverage; 
         FIG. 2  shows a schematic representation of a second embodiment of an automatic beverage maker according to the invention with regulated cold water supply into a caffeinated hot beverage; 
         FIG. 3  shows a schematic representation of a third embodiment of an automatic beverage maker according to the invention with regulated cold water supply into a caffeinated hot beverage; 
         FIG. 4  shows a schematic representation of a further embodiment of an automatic beverage maker according to the invention; 
         FIG. 5  shows a schematic representation of a fifth embodiment of an automatic beverage maker according to the invention; and 
         FIG. 6  shows a schematic representation of a sixth embodiment of an automatic beverage maker according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a first embodiment of an automatic beverage maker  1  according to the present invention. This embodiment includes several options for cooling the caffeinated hot beverage and the cold water supplied before it is fed to the hot beverage. These options can, of course, also be implemented separately in a plurality of other embodiments of the method, either analogously or in modified form. 
     The automatic beverage maker  1  is here designed as a fully automatic coffee maker. It has a water connection  2 , which can be connected to a conventional water tap, a house pipe or similar. 
     A supply line extends from water connection  2 . A pump  3  is arranged along the supply line, which delivers the water supplied to the automatic beverage maker  1  and/or applies pressure to it. 
       20  supply into both lines  4  and  5  is carried out by respective flow meters  6  and  7  for monitoring the respective volume and/or mass flow in the respective line, i.e. the hot water and cold water lines. In  FIG. 1 , a respective flow meter  6  and  7  is arranged after the division of the supply line on the cold water line  4  or the hot water line  5 .  Te,    
     In terms of flow, a non-return valve  8 , in particular a spring-loaded non-return valve  8 , is arranged along the hot water line  5  downstream of the flow meter  7 . A boiler  9  is then arranged along the hot water line  5 , which heats the supplied water to a temperature in the preferred range of 80° C. to 96° C. 
     In terms of flow, a directional control valve  10 , preferably designed as a 2/2 directional control valve, is arranged downstream of boiler  9 , in particular as an electrically operated 2/2 directional control valve with spring return, for transferring a discrete quantity of water to a brewing unit  11 . 
     The directional control valve  10  can interact with a control and/or evaluation unit  34  of the automatic beverage maker or communicate wirelessly or by wire. Thus, depending on the beverage selected by the user, it is possible to supply defined less or more water to the brewing unit  11 . For example, different amounts of water are required for coffees of different sizes. 
     Brewing unit  11  contains the ingredients for preparing the caffeinated hot beverage. This can preferably be ground coffee. The caffeinated hot beverage is therefore prepared in brewing unit  11  at a temperature typically above 70° C. 
     In terms of flow, valve  12  is arranged downstream of the brewing unit  11  as a directional control valve, preferably as a 3/2 directional control valve, in particular as an electrically operated 2/2 directional control valve with spring return, whereby part of the caffeinated hot beverage or the entire quantity of the caffeinated hot beverage can be directed into a secondary line  21  branching off the hot water line. The directional control valve  12  is switched by the control and/or evaluation unit  34 , depending on the type of beverage and the beverage temperature selected by the user. 
     In terms of flow, a supply line  29  of cooled caffeinated hot beverage from the secondary line  21  is arranged downstream of directional control valve  12 . 
     Finally, the uncooled or cooled caffeinated hot beverage can be transferred to a dispensing unit  13  comprising a directional control valve, preferably in form of a 3/2 directional control valve, in particular as an electrically operated 2/2 directional control valve with spring return, for dispensing  15  into a container, e.g. a cup or mug. Usually the dispensing unit  13  may have one or more additional lines  14 . 
     In terms of flow, after the flow meter  6 , a directional control valve  17  can be arranged along the cold water line  4 , preferably as a 2/2 directional control valve, in particular as an electrically operated 2/2 directional control valve with spring return. This directional control valve  17  is used to control the quantity of water to be cooled and defines a cold water quantity. It can also be operated by the control and/or evaluation unit  34 . 
     Downstream of directional control valve  17 , a return line  24 , returns cold water from a second cooling device  20  for indirect cooling of the caffeinated hot beverage. A non-return valve  25  is arranged along the return line  24 , which ensures that the cold water from the cold water line  4  is not conducted in the wrong direction through the second cooling device  20 , which can be designed as a heat exchanger. 
     The cold water with a temperature T 1  is then passed through a first cooling device  18 . This cooling device can preferably be used for indirect cooling of the cold water to a temperature T 2 , wherein T 2  is lower than T 1 , preferably at least 2 Kelvin, more preferably at least 5 Kelvin. For example, a Peltier element or another type of cooling can be used for this purpose. 
     The present application makes a distinction between direct cooling, in which a cold medium is introduced into a warm medium, e.g. cold water into warm water, and indirect cooling, wherein cooling takes place without introducing a medium into another medium. 
     A temperature sensor  19  for determining the cold water temperature after the first cooling device  18  may be installed at the outlet of the first cooling device. 
     The temperature sensor  19  determines an actual value  32 , which is passed on to the control and/or evaluation unit  34 . The latter compares the actual value  32  with a value for the type of beverage selected and/or for the temperature of the beverage selected for the cold water quantity predefined by the valve  17  and determines a control signal  33  for setting the first cooling device  18 , in particular the cooling capacity. 
     The cooled cold water with the temperature T 2  is fed to the second cooling device  20  as cooling medium for indirect cooling of the caffeinated hot beverage. In the second cooling device  20 , the cooling medium is fed in a separate cooling circuit, so that heat exchange takes place, but no mass transfers between the cooling medium and the caffeinated hot beverage. 
     After passing through the second cooling device  20 , the cooling water can be dispensed to the uncooled caffeinated hot beverage via a metering valve  27  designed as a throttle valve, optionally with a quantity metering function. For this purpose, the metering valve  27  is arranged on a cold water outlet  22  leading away from the second cooling device  20 , which enables a volume-metered supply of cold water from the cold water outlet  22  to the secondary line  21 . 
     Furthermore, the cold water outlet  22  is connected to the return line  24 , or it opens into this return line  24  along which the non-return valve  25 , in particular a spring-loaded non-return valve, is arranged. 
     At the outlet of the second cooling device  20  a temperature sensor  28  is placed to determine the temperature of the cooled hot beverage as it is dispensed to the user. This temperature sensor  28  communicates with the control and/or evaluation unit  34  by transmitting a measuring signal  30 , which is compared by means of an actual/desired value comparison for the selected beverage and the selected temperature, and a control signal  31  is transmitted to the metering valve  27  for transmitting the quantity of cold water in the uncooled caffeinated hot beverage. This defined quantity is then added. After the addition and before the second cooling device  20 , a homogenizer  26  may be arranged for optimum mixing of the caffeinated hot beverage and the supplied water. 
     In the example shown in  FIG. 1 , the direct cold water supply to the uncooled caffeinated hot beverage is carried Gut after the brewing process in the brewing unit  11 . Furthermore, after the cold water supply, the caffeinated hot beverage is indirectly after-cooled by the second cooling device  20 . 
     The regulation of the cold water supply is carried out depending on the mixing temperature after the completed indirect aftercooling. Furthermore, the cold water is cooled by the first cooling device  18  before being fed into the uncooled caffeinated hot beverage. 
       FIG. 1  shows several options of cooling systems, whose position in the method or in the automatic beverage maker can vary and which can also be provided only optionally. These options are briefly discussed again below. 
     The cold water supply is carried out in  FIG. 1  after the brewing operation in the brewing unit  11 . Other positions of the cold water supply are also possible. 
     Machine-controlled addition of cold water in this respect means that it is controlled or regulated by the machine and thus initiated, either by a line inside the machine through which the water for preparing the hot beverage flows or through which the already prepared hot beverage flows, or through a separate outlet directly into the vessel into which the prepared hot beverage is dispensed (the last variant is not shown here). 
     Indirect aftercooling can be achieved by an optional second cooling device  20 . 
     The regulation of the cold water supply is carried out depending on the mixing temperature, which is measured by temperature sensor  28 . The temperature can also be measured at a different position. It is also possible to provide regulation of the system using a different temperature, e.g. the temperature of the hot and/or cold water before merging. 
     The supplied cold water is actively cooled by the optionally provided first cooling device  18 . 
       FIG. 2  shows a second embodiment of an automatic beverage maker  41  according to the present invention. 
     Similar to  FIG. 1 , it comprises a water connection  42  from which a supply line with a pump  43  extends. Similar to  FIG. 1 , the supply line is divided into a cold water line  44  and a hot water line  45  each with a flow meter  46 ,  47 . The evaluation of the measuring signals of the flow meters  46 ,  47  for controlling the supply of water into the hot water and cold water lines, e. g. by corresponding valves or by the pump, is carried out by a control and/or evaluation unit  74 . 
     In terms of flow, after the flow meter  47 , a non-return valve  48 , in particular a spring-loaded non-return valve, is arranged along the hot water line  45 , followed by a boiler  49 , which heats the supplied water to a temperature in the preferred range of 80° C. to 96° C. 
     Behind the boiler  49 , a directional control valve  50  in a design similar to  FIG. 1  is arranged to transfer a discrete quantity of water to a brewing unit  51 . Between the control valve  50  and the brewing unit  51  a first supply line  62  of cold water, in the following also called cold water supply line, is arranged. 
     The function of the brewing unit  51  is already described in  FIG. 1 . The water supplied to the brewing unit  51  can be set at a lower temperature than in  FIG. 1 . 
     A temperature sensor  52  is located in outlet line  61  of brewing unit  51  to determine the coffee temperature after the brewing unit  51 . This temperature sensor  52 , in combination with the flow rates determined by the flow meters  46  and  47 , serves to adjust the amount of cold water supplied to the hot and cold water lines, e.g. by adjusting individual valves, e.g. individual or several regulating or metering valves shown in  FIG. 2 , and/or the pump  43 . 
     In the outlet  61  of the brewing unit, a second supply line  63  of cold water is arranged in terms of flow downstream of the temperature sensor  52 . 
     A homogenizer  66  is arranged after the cold water supply line  63 , followed by a second cooling device  60  for indirect aftercooling, especially of a caffeinated hot beverage already cooled by direct cooling. 
     After the second cooling device  60 , a further temperature sensor  68  is arranged to determine the cooled caffeinated hot beverage to be dispensed. 
     Finally, the uncooled or cooled caffeinated hot beverage can be dispensed to a dispensing unit  53 , with a 3/2 directional control valve analogous to  FIG. 1  and, optionally, comprising further outlets  54 . 
     After the flow meter  46 , a directional control valve  57  in a design similar to  FIG. 1  can be arranged along the cold water line  44 , analogous to  FIG. 1 . Also the amount of cold water supplied can be determined by the control and/or evaluation unit  74  on the basis of the volume and/or mass flow determined by the flow meter  46  in combination with the determined temperature at the temperature sensor  52 . 
     The cold water with a temperature T 1  can then pass through a first cooling device  58 , which cools the cold water down to a temperature T 2  (T 2 &lt;T 1 ). The first cooling device  58  is set by a signal  73  from the control and/or evaluation unit  74 , which compares a measuring signal  72  with another temperature sensor  59  downstream of the first cooling device  58  with a desired value. 
     Downstream of the further temperature sensor  59  is a metering valve  67  in the form of a throttle valve in analogous design to metering valve  27  in  FIG. 1 , which adjusts the quantity of the cold water supplied directly to the brewed caffeinated hot beverage. This is carried out depending on a measuring signal  70  of a mixing temperature determined by the temperature sensor  68  and a control signal  71  determined by the control and/or evaluation unit depending on the measuring signal  70  which is delivered to the throttle valve  67 . 
     The quantity of cold water set by the metering valve  67  can be fed directly via a supply line  63  or feed line into the outlet  61  of the brewing unit  51 . 
     Alternatively, the quantity of cold water set by the metering valve  67  can also be fed to the second cooling device  60  as a cooling medium and then fed to the hot water upstream of the brewing unit  51  via feeder  62  or the supply line. 
     As hot water within the terms of the present invention, the hot water can be in liquid form or also partly or completely in vapor form and be supplied from the boiler to the brewing unit. 
     The temperature measurement of the mixing temperature by the temperature sensor  68  at the outlet of the second cooling device  60  is used to control the metering valve  71  by means of an actual/desired value comparison. 
     The automatic beverage maker  41  allows cold water supply or the addition of cold water to the hot water before the brewing unit  51  and/or cold water supply or addition to the prepared caffeinated hot beverage after its provision in the brewing unit  51 . 
     Indirect cooling of the hot beverage, which is already pre-cooled by direct cold water injection, can be switched on or off as required. 
     The regulation of the cold water supply can be carried out depending on the mixing temperature of the dispensed caffeinated hot beverage. There is also active cooling of the cold water depending on the temperature of the cold water at temperature sensor  59 . 
       FIG. 2  shows several options of cooling systems, whose position in the method or in the automatic beverage maker can vary and which can also be provided only optionally. These options are briefly discussed again below. 
     In  FIG. 2 , the cold water is supplied either via line  63  after the brewing process in the brewing unit  51  or via line  62  before the brewing process in the brewing unit  51 . It is also possible to have only one line  62  or  63  at a time. 
     Indirect aftercooling is provided by the second cooling device  60 , which is only provided as an option. 
     The regulation of the cold water supply can be carried out depending on the mixing temperature, which is detected by the temperature sensor  68 . Here too, the temperature can be measured at a different position. It is also possible to provide regulation by using a different temperature, e.g. the temperature of the hot and/or cold water before merging. 
     The supplied cold water is actively cooled by the optionally provided first cooling device  58 . The cooling of the cold water can optionally be carried out in a controlled manner by the temperature sensor  59 . 
     The temperature and the quantity of cold water can be determined alternatively or additionally by a measurement made at temperature sensor  52 . 
       FIG. 3  shows a third embodiment of an automatic beverage maker  81  according to the invention with a water connection  82  from which a supply line with a pump  83  extends. After the pump  83  the supply line branches into a cold water line  84  and a hot water line  85 . The supply quantity into the two aforementioned water lines is measured by a flow meter  86 ,  87  each and set by a control and/or evaluation unit  114 . 
     The hot water line  85  has a non-return valve  88 , analogous to  FIGS. 1 and 2 , followed by a boiler  89  and a directional control valve  90  in the outlet of the boiler  89 , in the arrangement analogous to  FIGS. 1 and 2 . A first cold water supply line  105  is arranged between the directional control valve  90  and a downstream brewing unit  91 . By means of the cold water supplied upstream of the brewing unit  91 , the temperature of the water supplied to the brewing unit can be set to a lower temperature than the water provided by the boiler  89 . 
     A temperature sensor  92  is located at the outlet of the brewing unit  91  to determine the coffee temperature after the brewing unit  91 . This temperature sensor  92  is used in combination with the flow meters  86  and  87  to adjust the amount of cold water supplied to the hot and cold water lines. 
     In terms of flow, a directional control valve  93 , preferably as a 3/2 directional control valve, in particular as an electrically operated 2/2 directional control valve with spring return, is arranged downstream of the temperature sensor  92 , which enables the caffeinated hot beverage to be passed on directly to a dispensing unit  94  comprising a directional control valve, preferably a 3/2 directional control valve, and optionally further discharge lines, for the dispensing  105  of the caffeinated hot beverage. 
     Alternatively, the directional control valve  93  can divert the brewed quantity of caffeinated hot beverage to a secondary line. A direct feed  103  of cold water is made in this secondary line. For better mixing, the caffeinated hot beverage mixed with cold water can be fed to a homogenizer  106  and then to a second cooling device  100  for indirect aftercooling of the caffeinated hot beverage to a mixing temperature or target or dispensing temperature. A further temperature sensor  108  is arranged in the outlet of the second cooling device  100  for determining the output temperature of the caffeinated hot beverage, without taking into account the quantity of milk supplied through the supply line  96 . 
     After the supply line has been split, the cold water line  84  has a flow meter  86  for controlling, for example, a directional control valve  97  arranged on the cold water line  84 , which sends a measuring signal  118  to a control and/or evaluation unit  114 . The control and/or evaluation unit  114  can adjust the directional control valve  97  on the basis of the measuring signal and, optionally, by taking into account the measuring signal  113  determined by the temperature sensor  92 . 
     The same applies to the flow meter  87  of the hot water line  85 , with which e.g. the capacity of the pump  83  and/or the opening degree of the directional control valve  90  can be adjusted. Here too, the measuring signal of the temperature sensor  92  can be taken into account. 
     The cold water with a temperature T 1  can then be passed through a first cooling device  98 , whereby the cold water is cooled down to a temperature T 2  (T 2 &lt;T 1 ). The first cooling device  98  is set by a signal  116  from the control and/or evaluation unit  114 , which compares a measuring signal  115  from another temperature sensor  99  downstream of the first cooling device  98  with a desired value. 
     Downstream of the further temperature sensor  99  is a first metering valve  101  as a throttle valve, which adjusts the amount of cold water supplied to the brewed caffeinated hot beverage directly via a cold water supply line after the brewing unit  91 . Optionally, the cold water from the metering valve  101  can be fed as a cooling medium via a cooling medium supply line  102  to the second cooling unit  100 . 
     In the cooling medium outlet of the second cooling device  100  a second metering valve  104  is arranged as a throttle valve, which feeds cold water via a supply line  105  to the hot water line  85  before the brewing unit  91  after passing through the cooling device  100 . 
     Alternatively, the cooling medium of the second cooling device  100  can be discharged through a return line  96  before the first cooling device  98 . A non-return valve  95  is preferably arranged along this return line  96 . 
     Both the signals  111  and  112  for setting the first metering valve  101  and the second metering valve  104  are generated by a control and/or evaluation unit  114  as a function of a measuring signal  110  from the temperature sensor  108  to determine the target or output temperature of the caffeinated hot beverage. 
     The control of the first cooling device  98  via the control signal  116  can be carried out analogously to  FIG. 1 or 2 . 
       FIG. 3  shows several options of cooling systems, whose position in the method or in the automatic beverage maker can vary and which can also be provided only optionally. These options are briefly discussed again below. 
     In  FIG. 3 , the cold water is supplied either via line  103  after the brewing operation in the brewing unit  91  or via line  105  before the brewing operation in the brewing unit  91 . It is also possible to provide only one line  103  or  105  at a time. 
     Indirect aftercooling is provided by the second cooling device  100 , which is only provided as an option. 
     The regulation of the cold water supply can be carried out depending on the mixing temperature, which is detected by the temperature sensor  99 . Here too, the temperature can be measured at a different position. It is also possible to control the system using a different temperature, e.g. the temperature of the hot and/or cold water before merging. 
     The supplied cold water is actively cooled by the optionally provided first cooling device  98 . The cooling of the cold water can optionally be controlled by the temperature sensor  99 . 
     The temperature and/or the amount of cold water can be determined alternatively or additionally depending on a measurement which is made at temperature sensor  92 . 
     In the embodiment of  FIG. 3 , the two metering valves  101  and  104  can be controlled by the control and/or evaluation unit  114  or optionally only one of the two metering valves. 
       FIG. 4  shows a fourth embodiment of an automatic beverage maker  121  according to the invention, which has a water connection  122  with a connecting supply line with a pump  123 . The supply line then branches into a cold water line  124  and a hot water line  125 , each with a flow meter  126 ,  127 . Downstream of flow meter  127 , a non-return valve  128  is arranged on the hot water line  125  analogously to  FIGS. 1-3 . Then, a boiler  129  is arranged on the hot water line  125 . At the outlet of the boiler  129  a directional control valve  130  is arranged followed by a brewing unit  131 . The function of the individual components is explained in detail in the exemplary embodiment in  FIG. 1 . 
     Cold water is then added to the brewed caffeinated hot beverage by direct supply via line  142  after passing through indirect cooling device  140 . The cooled hot beverage is then passed through a homogenizer  132 . This mixture is then passed through the second cooling device  140  and cooled. After passing through the second cooling device, the temperature of the cooled caffeinated hot beverage is determined by a temperature sensor  148 . The measured value  143  is fed to a control and/or evaluation unit  144 , which adjusts the temperature of the cold water supplied to the hot beverage accordingly. 
     The automatic beverage maker  121  has a dispensing unit  133  analogous to  FIGS. 1-3  for dispensing  135  into a container. The dispensing unit  133  can have further outlets  134 . 
     The cold water line  124  has a directional control valve  137 , a first cooling device  138  and a temperature sensor  139  analogous to  FIG. 1 . The temperature sensor  139  is used to set the temperature of the cold water by means of the control and/or evaluation unit  144 , by actual/desired value comparison of the measuring signal  146  of the temperature sensor  139 . Subsequently, the control and/or evaluation unit  144  transmits a control signal to the first cooling device  138 . In terms of flow, a metering valve  141  is arranged downstream of the temperature sensor  139  in the form of a throttle valve, which meters the quantity of cold water for supply to the second cooling device  140  and the subsequent quantity of cold water for direct supply to the caffeinated hot beverage via line  142 . This metering valve  141  is controlled by a control signal  145  depending on the temperature of the temperature sensor  148 . 
     The embodiment in  FIG. 4  has a cold water supply after the brewing process and an optional aftercooling. The cold water supply depends on the mixing temperature. A likewise optional active cooling of the cold water is realized by the first cooling device  138 . 
       FIG. 5  shows an automatic beverage dispenser  151  with a water connection  152 , a pump  153 , a cold water line  154  and a hot water line  155 , each with a flow meter  156 ,  157 . The hot water line  155  also has a non-return valve  158  analogous to  FIGS. 1-4 , a boiler  159 , a directional control valve  160  and a brewing unit  161 , which is used to prepare an uncooled caffeinated hot beverage. 
     Along the cold water line  154 , there is a directional control valve  167  and a metering valve  171  designed as a throttle valve for measuring a specific amount of cold water for metering into the uncooled caffeinated hot beverage. This is carried out via a secondary line  172  into the outlet of the brewing unit  161 . The cold water/hot beverage mixture can then be mixed in a homogenizer. The target or output temperature is then determined by a temperature sensor  178 . 
     Dispensing  165  of the caffeinated hot beverage is carried out by a dispensing unit  163  comprising a directional control valve and, optionally, further outlets  164 . 
     The temperature sensor  178  determines a measuring signal  175 , transmits this to a control and/or evaluation unit  174  and passes a control signal  173  to the metering valve  171  for metering the directly supplied cold water quantity. 
       FIG. 5  shows an embodiment without indirect aftercooling after the addition of cold water. 
       FIG. 6  shows another embodiment of an automatic beverage maker  181  with a water connection  182 , a pump  183 , a cold water line  184  and a hot water line  185 , each with a flow meter  186 ,  187 . The hot water line  185  also has a non-return valve  188  analogous to  FIGS. 1-5 , a boiler  189 , a directional control valve  190 , in analogous design of  FIGS. 1-4 , followed by a cold water supply line  206  upstream of a brewing unit  191  and a homogenizer  196  upstream of the brewing unit  191 . 
     A directional control valve  192 , preferably a 3/2 directional control valve, is arranged in the outlet of the brewing unit for feeding the hot beverage enriched with cold water to a second cooling device  200  for indirect aftercooling or for direct feeding of the hot beverage without indirect aftercooling to an dispensing unit  193  comprising optional further outlets  194  and a directional control valve. In this unit the dispensing  195  of hot beverage takes place. 
     In terms of flow, the second cooling device  200  is followed or arranged downstream of a temperature sensor  203 , which determines a measuring signal  209  of the cooled hot beverage and transmits this to a control and/or evaluation unit  211 . 
     Along the cold water line  184  there is a directional control valve  197 , a return line  205  of cooling water from the second cooling device  200  with a non-return valve  199 , a downstream first cooling device  198  with a downstream sensor  202  and a controller of the first cooling device analogous to the embodiment variant of  FIGS. 1-5 . The cold water is passed as cooling medium through the second cooling device  200  and then either fed to the return line  205  or via a metering valve  204 , designed as a throttle valve, to the supply line  206 , which is supplied by a control signal  206  depending on a measuring signal  209  of the temperature sensor  203 . 
     Individual embodiments of the methods according to the invention with automatic beverage makers according to  FIGS. 1-6  are described below as follows: 
     After brewing, the temperature is measured before the caffeinated hot beverage is dispensed and after indirect aftercooling by the second cooling device. In  FIGS. 1-6 , cooling is achieved by indirect aftercooling through the second cooling device and by direct cooling by supplying cold water via at least one metering valve. 
     The opening of the preferably electrically adjustable metering valve and thus the supplied cold water quantity is controlled depending on the stored desired temperature or target temperature or output temperature after the last cooling. On the basis of the resulting mixing temperature measurement after indirect aftercooling, continuous monitoring is carried out by the corresponding temperature sensor and a correspondingly adapted cold water supply. 
     In the variants in  FIGS. 1-4 and 6 , the temperature of the cold water supplied is stabilized at a low level by “pre-cooling” using a first cooling device. Such pre-cooling enables the system to compensate for temperature fluctuations of the cold water used and thus to balance out fluctuations in the line and/or ambient temperature. 
     Furthermore, pre-cooling enables the optimum setting of the mixing temperature or the output temperature of the caffeinated hot beverage, because the lower the temperature of the supplied water, the lower the desired value range of the mixing temperature can be set. The lower the temperature of the supplied water, the less cold water is required to reach the target range of the mixing temperature. This means that a particularly highly concentrated hot beverage containing caffeine can be made available to the user. 
     Such a pre-cooling of the cold water can be realized by a storage or continuous flow cooler and can be operated electrically or by water or cooling medium. A line area cooled by a Peltier element is considered particularly advantageous. 
     Preferably, the temperature of the cold water is measured after and/or in the water cooling system, especially after and/or in the first cooling device. Preferably, depending on the measured temperature, the cooling of the cold water is controlled and/or adjusted by a control and/or evaluation unit. 
     Alternatively or additionally, it is possible to measure the temperature of the brewed caffeinated hot beverage after the brewing unit, but before further cooling, and to calculate and set the amount of cold water required to reach the specified mixing temperature. This embodiment is realized, among others, in  FIGS. 2 and 3  by setting the valves of the hot water and cold water lines under consideration of the flow rate in the respective line. However, other variants of setting are also conceivable, e. g. by setting one or more metering valves. The quantities can be monitored and adjusted by measuring the flow rate, e.g. using impeller meters or electromagnetic flowmeters. 
     In combination with a control and/or evaluation unit, the metering valve or metering valves enable the volume flows to be adjusted for optimum mixing of the brewed coffee with the cold water and to ensure uniform discharge characteristics. 
     As shown in  FIGS. 1-6 , the embodiments of the concept can be used in different combinations as well as independently of each other. 
     Furthermore,  FIGS. 1-6  show different embodiments for a controlled addition of cold water to a caffeinated hot beverage within an automatic beverage maker. 
     Preferably, the hot water/cold water mixture can be fed to a homogenizer before the evaluating temperature measurement before or in the dispensing unit, so that an optimal mixing and heat energy transfer can be ensured by homogenization. 
     The cold water can be advantageously passed through an indirect heat exchanger, in particular the aforementioned second cooling device, before being fed directly into the caffeinated hot beverage. 
     The mixture, e.g. the coffee-cold water mixture, is passed through this heat exchanger to further reduce the temperature of the mixture. 
     Furthermore, cold water can be supplied before and/or after the brewing process, as can be seen from the different embodiments in  FIGS. 1-6 . Individual process steps and flow guides of  FIGS. 1-6  can also be transferred to other embodiment variants. 
     Preferably, the brewed coffee can, via a valve behind the brewing unit in the flow direction, either be sent directly to the dispensing unit or be fed into the cooling system with the cold water supply and, if necessary, the first and/or second cooling device. The direct supply line with bypassing of the cooling system is advantageous in order not to unnecessarily lower the temperature of a coffee beverage that does not need to be cooled. Preferably, the metering unit can be arranged in an indirect aftercooling, preferably after the cooling, preferably at the intersection between the hot water line and the secondary line. 
     If the metering unit is arranged directly before the supply of cold water to the caffeinated hot beverage, cold water should preferably be returned to the cooling circuit, in particular before the first cooling device, in order to supply a proportionate quantity of cold water, adjustable via the metering valve, to the coffee over the entire reference time and in this process to continue to flow through the indirect aftercooling system. 
     At the beginning of the production of the caffeinated hot beverage, a data record specific to the hot beverage, which comprises water quantities (beverage size), mixing ratio (coffee concentration), water temperatures and/or target temperature, is provided by the control and/or evaluation unit based on the selection of the type of hot beverage by the user. 
     In the following, an embodiment of a method for the production of a caffeinated hot beverage is described by way of example with reference to the figures, in particular  FIG. 2 : 
     In a first step, cold water can be pumped through the cooling system with the pump and led into a drain until the temperature of the first measuring point of the temperature measurement after aftercooling is approximately the same as the temperature of the measuring point in the cold water line, which measuring point is downstream of a pre-cooling of the cold water. This step serves to dispose of the hot water from the pipes and to pre-cool the lines and components of the automatic beverage maker. 
     The brewing process can be started in a second step. Here, the brewed caffeinated hot beverage, e.g. hot coffee, is fed to the second cooling device optionally via a valve and in parallel cold water is fed to the coffee from a cold water supply line. The supply is carried out depending on the measured temperature after aftercooling by the second cooling device in conjunction with the cold water temperature, which is determined after the first cooling device, or in the absence of such a cooling device, in the cold water line. This can preferably be a so-called readjustment, provided that the temperature measured after aftercooling exceeds a desired value. 
     In a third step, the cold water volume flow can be controlled via the metering valve and, if necessary, e.g. in the event of a deviation from the desired value, the temperature of the cold water in the cold water cooling system and/or the supplied water quantities can be adjusted. 
     Cooled cold water which is not fed into the coffee by the volume flow and/or mass flow control of the metering valve can be fed back into the cold water line or cold water system via the return pipe in a fourth step. This creates a cooling circuit that improves the efficiency of the water cooling system and ensures the flow of indirect aftercooling, even with small direct additions to the coffee. 
     The coffee-cold water mixture can be homogenized in a further step after the cold water has been added to ensure optimum mixing and heat energy transfer. 
     In a subsequent step to homogenization, the cooled coffee can be passed through indirect aftercooling, which further reduces the temperature by heat transfer with a cooling medium in the form of indirect cooling. 
     Finally the coffee can be dispensed.