Abstract:
Provided are methods for automatically producing milk froth in a milk-frothing apparatus, and also a milk-frothing apparatus for automatically producing milk froth. The milk-frothing apparatus has at least one hollow space, a steam-inlet channel for introducing steam into the hollow space, a milk-inlet channel for introducing milk into the hollow space, an air-inlet channel for introducing air into the hollow space, and an outlet channel for discharging milk froth from the milk-frothing apparatus, wherein the respective channels each issue directly or indirectly into the hollow space. With the aim of specifying a method and a milk-frothing apparatus by means of which an organoleptic milk froth of which the taste is optimized can be automatically produced, the invention makes provision for steam, preferably steam from water, to be introduced into the steam-inlet channel in order to allow milk and air to flow into the hollow space and in order to mix said milk, air and steam to form a milk/air/steam mixture, and to then output the milk/air/steam mixture into the outlet channel, wherein a sweetening means is provided in a region of the milk-frothing apparatus through which at least the milk/air/steam mixture flows.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of and claims priority to International Application No. PCT/CH2011/000310, filed Dec. 30, 2011, which claims priority to EP Application No. 10016188.4, filed Dec. 30, 2010, the entire contents each of which are incorporated herein by reference. 
     
    
     TECHNOLOGICAL FIELD 
       [0002]    The invention relates to a method for automatically producing milk froth in a milk-frothing apparatus and to a milk-frothing apparatus for automatically producing milk froth. 
       BACKGROUND 
       [0003]    Automatic milk-frothing apparatuses, which can be arranged at fully automatic coffee machines, for example, are known from technology, wherein the milk froth for coffee beverages, such as cappuccino, for example, is produced automatically by means of such a known milk-frothing apparatus and is output at one end of a milk froth outputting channel. In such milk-frothing apparatuses, the venturi effect is used for the suction process and further transportation as well as for the necessary mixing of the milk, wherein hot steam, generally steam from water, is introduced in an area of the known milk-frothing apparatus, so that this steam flows past a milk-inlet channel and thereby generates a low pressure, wherein milk is in each case sucked in from a storage container through the milk-inlet channel due to the low pressure. 
         [0004]    This milk, which is sucked in by means of the steam, flows through a hollow space in the interior of such a known milk-frothing apparatus and is mixed at that location. In the case of such known milk-frothing apparatuses, it is additionally known to provide for an air-inlet channel, through which air, which is mixed together with the milk in the hollow space, in addition to the milk is also sucked in when the steam from water flows by. The milk or the milk-steam mixture, respectively, if necessary enriched with air to form a milk-steam-air mixture, reaches from the hollow space into a so-called emulsion chamber, in which the frothing process is concluded and the mixed mixtures is slowed down. An output channel for the mixture, which is produced, connects to the emulsion chamber. Said output channel leads out of the milk-frothing apparatus and generally leads into a milk froth output apparatus of the fully automatic coffee machine. 
       SUMMARY 
       [0005]    Based on the outlined problems, the invention at hand is based on the task of specifying a method for automatically producing milk froth, which delivers an organoleptic milk froth, of which the taste is optimized, which is particularly fine, dense, creamy and appealing in terms of taste. 
         [0006]    This object is solved by means of a method comprising the features of patent claim  1 . 
         [0007]    The method for automatically producing milk froth is based on a milk-frothing apparatus, which encompasses at least one hollow space, a steam-inlet channel for introducing steam into the hollow space, a milk-inlet channel for introducing milk into the hollow space, an air-inlet channel for introducing air into the hollow space, and an outlet channel for discharging milk froth from the milk-frothing apparatus, and an emulsion chamber, which is arranged between the hollow space and the outlet channel, wherein the steam-inlet channel, the milk-inlet channel, the air-inlet channel, the emulsion chamber and the outlet channel are in each case directly or indirectly connected to the hollow space and a milk-air-steam mixture can be produced in the hollow space by introducing steam into the hollow space and can be introduced into the emulsion chamber. The method encompasses at least the following method steps: (i) introducing steam into the steam-inlet channel, so as to let milk and air flow into the hollow space and to mix them to form a milk-air-steam mixture, and (ii) outputting the milk-air-steam mixture from the emulsion chamber into the outlet channel. 
         [0008]    According to the invention, a sweetening means, which is present in solid form, the emulsion chamber, wherein the sweetening means is embodied as a body, which is shaped to form a block, and this body is arranged in the emulsion chamber before the introduction of steam into the steam-inlet channel takes place, so that the milk-air-steam mixture flows around the sweetening means and the sweetening means is dissolved in the milk-air-steam mixture. 
         [0009]    The method according to the invention has considerable advantages as compared to the state of the art. On the one hand, adding the sweetening means, preferably sugar, in an area, through which the milk-air-steam mixture flows directly during the milk-frothing process, has a substantially even impact on the entire milk quantity, which flows through the milk-frothing apparatus, or on the milk-air-steam mixture, which flows through the milk-frothing apparatus, whereby a sweetened milk froth is produced, which surprisingly (as compared to the milk froth, to which no sweetening means was added in response to the frothing of the respective milk) encompasses a finer and denser structure and which is creamier, which has a positive effect on the taste and on the organoleptics when consuming a coffee beverage, which was prepared with such a milk froth. 
         [0010]    It is thus furthermore ensured that the taste-improving, sweetening characteristics of the sweetening agent are distributed very evenly, based on the total volume of milk, which flows through the milk-frothing apparatus, so that the total volume of milk froth tastes sweet. 
         [0011]    Last but not least, by already introducing the sweetening means within the milk-frothing apparatus, it is attained that already sweetened milk froth is output from the milk-frothing apparatus when the method according to the invention is carried out, which makes it unnecessary to additionally sweeten the coffee beverage, which is provided with such a milk froth. 
         [0012]    Due to the fact that the milk-frothing apparatus encompasses an air-inlet channel, which is indirectly or directly connected to the hollow space, and into which air flows, it is attained that this air is mixed together with the milk, whereby the froth structure of the milk froth, which is produced, can be varied, for example by increasing or decreasing the air-inlet channel cross section, depending on the added air quantity. By means of such an air-inlet channel, which is preferably designed so as to be variable, the advantage can be attained that heated milk is output from the milk-frothing apparatus in combination with a particularly fine-pored milk froth in particular when adding air to the milk (which is cold, if necessary), which flows into the hollow space, wherein the milk froth encompasses the fine and dense froth structure, which is advantageous according to the invention, and in addition that the heated output milk as well as the milk froth are already sweetened when being output from the milk-frothing apparatus. 
         [0013]    The emulsion chamber is arranged between the hollow space and the outlet channel of the milk-frothing apparatus, the milk-air-steam mixture—starting at the hollow space—flows through the emulsion chamber to the outlet channel, so that the milk-air-steam mixture in each case flows through the emulsion chamber (downstream from the hollow space and upstream of the outlet channel), wherein the sweetening means is then only introduced into the emulsion chamber when the method according to the invention is carried out. This is advantageous in particular when the emulsion chamber is embodied so as to be accessible from the outside and when it is possible to manually introduce the sweetening means into the emulsion chamber. 
         [0014]    Provision can be made for using sweetening means in solid form, for example in the form of a body, which is shaped to form a block (e.g. as a lump of sugar and preferably in the form of a cylinder-shaped, cube-shaped or ball-shaped lump of sugar). A solid sweetening means has the advantage of an improved handling. The solid sweetening means can thereby in particular be formed such that at least the milk-air-steam mixture flows around it or also through it. Provision can thus be made, for example, to embody the solid sweetening means as a lump of sugar (e.g. as a sugar cube), which encompasses a hole, through which the milk-air-steam mixture can flow. It is then attained with such a design that the surface of such a lump of sugar is enlarged, so as to result in an improved or quicker dissolvability, respectively, of the lump of sugar in the milk-air-steam mixture, which flows through the respective hole and/or which flows around the respective lump of sugar, due to the enlarged surface. 
         [0015]    In the case of the method according to the invention, provision can furthermore be made for the sweetening means to be introduced into the area emulsion chamber of the milk-frothing apparatus, before the steam is introduced into the steam-inlet channel. It is ensured through this that the sweetening means is available immediately for being mixed, as soon as the milk-steam-air mixture reaches the area, in which the sweetening means is positioned. It can thereby in particular be attained that the sweetening means can impact the milk, which is mixed in the milk-frothing apparatus, for a particularly long period of time and that the respective produced milk froth is sweetened to a particularly intensive and even extent. 
         [0016]    An apparatus for automatically producing milk froth (hereinbelow “milk-frothing apparatus”) according to the method according to the invention encompasses at least one hollow space, a steam-inlet channel for introducing steam into the hollow space, a milk-inlet channel for introducing milk into the hollow space, an air-inlet channel for introducing air into the hollow space and an outlet channel for outputting milk froth from the milk-frothing apparatus. The steam-inlet channel, the milk-inlet channel, the air-inlet channel and the outlet channel are thereby in each case directly or indirectly connected to the hollow space, so that steam, which is introduced through the steam-inlet channel, milk, which is introduced through the milk-inlet channel, and air, which is introduced through the air-inlet channel, can be mixed in the hollow space to form a milk-air-steam mixture and so that the milk-air-steam mixture can be output from the milk-frothing apparatus through the outlet channel. Such a milk-frothing apparatus furthermore encompasses a device for introducing sweetening means into an area of the milk-frothing apparatus, through which at least the milk-air-steam mixture flows during a frothing process. 
         [0017]    Such a device for introducing sweetening means, which is provided at such a milk-frothing apparatus, makes it possible in an advantageous manner to produce dense and creamy milk froth, which is evenly sweetened and the froth structure of which is particularly fine or fine-pored, respectively, by automatically producing milk froth during a frothing process. 
         [0018]    The milk-frothing apparatus encompasses an emulsion chamber, which is arranged between the hollow space and the outlet channel, wherein the emulsion chamber is connected to the hollow space and the outlet channel such that the milk-air-steam mixture can flow through at least one area of the emulsion chamber during a frothing process, wherein the device for introducing sweetening means is embodied to introduce the sweetening means into the area of the emulsion chamber, through which the milk-air-steam mixture can flow. The milk-air-steam mixture thereby flows through the emulsion chamber during a frothing process. Such a device for introducing sweetening means into the emulsion chamber of the milk-frothing apparatus can allow for a pivoting of the emulsion chamber, for example, so that the emulsion chamber or at least a partial area of the emulsion chamber becomes accessible from the outside and that solid and/or liquid sweetening means can be introduced into the emulsion chamber. It is furthermore possible to embody such a device for introducing sweetening means into the emulsion chamber as an opening to the emulsion chamber interior, wherein sweetening means can be introduced into the interior of the emulsion chamber through the opening and wherein the opening can be closed after the sweetening means has been introduced in preparation for a frothing process. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    Exemplary embodiments of a milk-frothing apparatus, in particular for use in a method according to the invention for automatically producing milk froth, will be explained in more detail below by means of a drawing, in which: 
           [0020]      FIG. 1  shows a sectional view onto a first exemplary embodiment of a milk-frothing apparatus; 
           [0021]      FIG. 2  shows a sectional view onto a second exemplary embodiment of a milk-frothing apparatus; and 
           [0022]      FIG. 3  shows a sectional view onto a third exemplary embodiment of a milk-frothing apparatus. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]      FIG. 1  shows a sectional view onto a first exemplary embodiment of a milk-frothing apparatus  100 , in particular for carrying out a method for automatically producing milk froth according to the invention. According to  FIG. 1 , the milk-frothing apparatus  100  encompasses a hollow space  10 , into which steam, in particular steam from water, can be introduced through a steam-inlet channel  11 , so that said steam flows through the hollow space  10 . A further channel, which branches into a milk-inlet channel  13  and an air-inlet channel  12 , is furthermore directly connected to the hollow space  10  and is illustrated in  FIG. 1  so as to be located to the right of the hollow space  10 . The air-inlet channel  12  allows for air to flow into the hollow space  10 , while the milk-inlet channel  13 , at its end, which faces away from the hollow space  10 , leads into a storage container for milk, which is not shown in  FIG. 1 . 
         [0024]    Provision can furthermore be made for a regulating valve  60 , which partially closes the milk-inlet channel  13  for the purpose of adding the milk. In the event that steam is introduced into the steam-inlet channel  11 , a low pressure is created based on the Venturi effect when flowing past the mouth area of the channel system with the air-inlet channel  12  and the milk-inlet channel  13 , whereby milk and air are sucked in and are introduced into the hollow space  10 . This introduced and sucked-in mixture of milk, air and steam (“milk-air-steam mixture”) is then mixed in the hollow space  10 , which contributes to the production of the milk froth. The milk-air-steam mixture then reaches into an emulsion chamber  50 , in which the turbulent flow, which is still present in the hollow space  10 , is slowed down and the milk-air-steam mixture is homogenized, so that an emulsion of milk (drops), steam (bubbles) and/or air (bubbles), which form the milk froth, is produced in the emulsion chamber  50 . 
         [0025]    In the shown first exemplary embodiment according to  FIG. 1 , the further mixing of the milk, which is sucked in, with the steam and the air, which is also sucked in, takes place in the emulsion chamber  50 , whereby the milk froth is produced or its structure is influenced or densified, respectively. 
         [0026]    As is suggested in  FIG. 1 , the emulsion chamber  50  in the example at hand is divided into two partial spaces—the first partial space  50   a  and the second partial space  50   b -, wherein the partial spaces  50   a  and  50   b  are connected by means of a connection channel  51 . The partial space  50   a  is thereby connected to the hollow space  10  such that the respective mixture of milk, steam and air, which is produced in the hollow space  10 , is introduced into the first partial space  50   a  of the emulsion chamber  50  and can subsequently reach into the second partial space  50   b  of the emulsion chamber  50  only via the connection channel  51 . As is suggested in FIG.  1 —the connection channel  51  has a cross sectional surface, which is considerably smaller (e.g. by more than a factor of 2) than a cross sectional surface of the first partial space  50   a.  Due to the fact that the connection channel  51  is accordingly relatively narrow as compared to the partial space  50   a  and to the partial space  50   b,  it is attained that the mixture of milk, steam and air, which is in each case introduced into the first partial space  50   a  of the emulsion chamber  50 , backs up initially, before it can flow into the second partial space  50   b  of the emulsion chamber  50 , so that the mixture of milk, steam and air can initially mix or homogenize and calm down, respectively, in the first partial space  50 . When the mixture of milk, steam and air, which is backed up in the first partial space  50   a,  finally flows through the connection channel  51  into the second partial space  50   b  of the emulsion chamber  50 , it is typically accelerated in the connection channel  51  in the longitudinal direction of the connection channel  51 , so that the mixture of milk, steam and air flows through the connection channel  51  in the form of a flow, the flow speed of which encompasses a gradient, which is oriented substantially parallel to the flow speed (that is, in longitudinal direction of the connection channel  51 ). This flow has the effect that milk drops or bubbles of steam and/or air, respectively, are deformed in the flow in the direction of the gradient of the flow speed, wherein the deformation of the respective milk drops or bubbles of steam and/or air, respectively, is greater, the greater the speed gradient is. In the example at hand, the length and the cross sectional surface of the connection channel  51  can be chosen such that milk drops or bubbles of steam and/or air, respectively, which flow through the connection channel  51 , are deformed in the connection channel  51  to the extent that individual milk drops are in each case divided into a plurality of smaller milk drops, and individual bubbles of steam and/or air are in each case divided into a plurality of smaller bubbles of steam and/or air. Accordingly, the division of the emulsion chamber  50  into the partial spaces  50   a  and  50   b  and the connection of the partial spaces  50   a  and  50   b  by means of the connection channel  51  a ensures that the mixture of milk, steam and air, which flows via the connection channel  51  into the second partial space  50   b  of the emulsion chamber  50 , comprises particularly small milk drops and particularly small bubbles of steam and/or air and accordingly forms a particularly fine-pored milk froth. 
         [0027]    As is suggested in  FIG. 1 , a sweetening means  80 A has been introduced into the emulsion chamber  50  (into the first partial space  50   a  of the emulsion chamber  50  in the example at hand) in the example at hand—even before steam is introduced into the steam-inlet channel  11 , so as to suck milk and air into the hollow space  10  and so as to allow the steam to flow into the hollow space  10  together with the milk, which has been sucked in, and the air, which has been sucked in. In the example at hand, the sweetening means  80 A is present in the form of a lump of sugar, which encompasses a continuous hole  80 - 1  (suggested in  FIG. 1  by means of two dashed lines, which identify the surface of the lump of sugar, which defines the hole  80 - 1 ). 
         [0028]    When steam is finally introduced into the steam-inlet channel  11  after introducing the sweetening means  80 A into the emulsion chamber  50 , so that milk and air is sucked into the hollow space  10  and the steam flows into the emulsion chamber  50  in the form of a milk-air-steam mixture together with the milk, which is sucked in, and the air, which is sucked in, the respective milk-air-steam mixture flows around the surface of the sweetening means  80 A and can thereby also flow through the hole  80 - 1 , resulting in the sweetening means  80 A being dissolved at least partially or completely, if applicable, in the respective milk-air-steam mixture, whereby a milk froth, which is homogenously sweetened and the structure of which is fine and dense, is embodied, which subsequently flows through the connection channel  51  and reaches into the second partial space  50   b  of the emulsion chamber  50 . An outlet channel  70  in the form of an outlet ring gap, through which the automatically produced sweetened milk froth is subsequently output from the emulsion chamber  50 , is embodied in the lower area of the milk-frothing apparatus  100 , which is shown in  FIG. 1 . 
         [0029]    It is pointed out that, in the case of the sweetening means  80 A, which is illustrated in  FIG. 1 , the continuous hole  80 - 1  is not absolutely necessary. The sweetening means  80 A illustrated in  FIG. 1  can be embodied so as to be cylindrical, cube-shaped or rectangular-shaped or can also be replaced with a lump of sugar, comprising any other form, for example a ball-shaped lump of sugar. Each of the above-mentioned lumps of sugar can be arranged in the emulsion chamber  50 , preferably in the first partial space  50   a  of the emulsion chamber  50   a , before the milk-air-steam mixture is introduced into the emulsion chamber  50 , whereby the milk-air-stream mixture, which is in each case introduced into the emulsion chamber  50 , flows around the respective lump of sugar in the emulsion chamber  50  and thereby dissolves it. The respective lump of sugar can comprise 1-3 grams of sugar, for example (that is, the quantity of sugar, which is contained in a standard sugar cube). 
         [0030]    To make it possible for the sweetening means  80 A in the exemplary embodiment according to  FIG. 1  to be introduced into the emulsion chamber  50 , the milk-frothing apparatus  100  is designed such that it is comprised of two parts—an upper part  100 - 1  and a lower part  100 - 2 , wherein the lower part  100 - 2  can be moved relative to the upper part  100 - 1  between different positions. In one of the respective positions (as is illustrated in  FIG. 1 ), the upper part  100 - 1  and the lower part  100 - 2  together define the emulsion chamber  50 . In the example at hand, the upper part  100 - 1  comprises the hollow space  100 , the steam-inlet channel  11 , the milk-inlet channel  13  and the air-inlet channel  12 , among others. 
         [0031]    On a side, which faces the upper part  100 - 1 , the lower part  100 - 2  encompasses a recess  105 - 2 , which forms at least a part of the emulsion chamber  50 . As is suggested in  FIG. 1 , the upper part, on a side facing the lower part  100 - 2 , can encompass a recess  105 - 1 , which is connected to the hollow space  10 , so that—when the lower part  100 - 2  has been brought into the position illustrated in  FIG. 1  relative to the upper part  100 - 1 —the recess  105 - 2  together with the recess  105 - 1  form the first partial space  50   a  of the emulsion chamber  50 . Based on the position illustrated in  FIG. 1 , the lower part  100 - 2  can be moved relatively to the upper part  100 - 1  into another position (not illustrated in  FIG. 1 ), in which the lower part  100 - 2  is separated from the upper part  100 - 1  such that the emulsion chamber  50  can be accessed from outside and is thus open, so that the sweetening means  80 A (in the form illustrated in  FIG. 1 ) can be introduced into the emulsion chamber  50  (e.g. into the first partial space  50   a  of the emulsion chamber  50 ). When the lower part  100 - 2  is separated from the upper part  100 - 1 , the sweetening means  80 A (as a whole in one piece) can be arranged in the recess  105 - 2 , for example, in the lower part  100 - 2 . The lower part  100 - 2  can subsequently be brought back into the position illustrated in  FIG. 1 , wherein the emulsion chamber  50  is closed. The sweetening means  80 A in the emulsion chamber  50  is thus encased between the upper part  100 - 1  and the lower part  100 - 2 , when the lower part  100 - 2  is brought back into the position illustrated in  FIG. 1 . 
         [0032]    To be able to move the lower part  100 - 2  relative to the upper part  100 - 1 —as mentioned above—between different positions in a simple manner, the lower part  100 - 2  and the upper part  100 - 1  can be connected by means of suitable coupling elements, for example. Such coupling elements can be realized in a variety of ways, for example as screw coupling or plug-in coupling. The lower part  100 - 2  and the upper part  100 - 1  can be connected such, for example, that the lower part  100 - 2  and the upper part  100 - 1  can be connected to one another or separated from one another by means of a plug-in/rotary movement. For this purpose—as suggested in FIG.  1 —the upper part  100 - 1  can be equipped at its lower end with a thread  102 - 1  and the lower part  100 - 2  can be equipped at its upper end with a thread  102 - 2 , wherein the thread  102 - 2  is adapted to the thread  102 - 1  such that a screw connection between the lower part  100 - 2  and the upper part  100 - 1  can be established or such a screw connection can be released via the threads  102 - 1  and  102 - 2 , respectively, by rotating the lower part  100 - 2  about a longitudinal axis L. In this case, the lower part  100 - 2  can be unlocked by means of a manual rotation and can subsequently be removed downward in axial direction and can thus be separated from the upper part  100 - 1 . The respective inclines of the threads  102 - 1  and  102 - 2  can be chosen such, for example, that the lower part  100 - 2  must in each case be rotated by approx. 90° about the longitudinal axis L for establishing or releasing the mentioned screw connection, respectively. 
         [0033]    After separating the lower part  100 - 2  from the upper part  100 - 1 , the user can manually place the sweetening means  80 A, in the case at hand in the form of the lump of sugar illustrated in  FIG. 1 , into the lower part  100 - 2  or into the recess  105 - 2 , respectively, which is embodied in the lower part  100 - 2 . The lower part can subsequently be fastened to the upper part  100 - 1  again by means of an axial lifting movement and rotation (according to the arrangement of the lower part  100 - 2  illustrated in  FIG. 1 ). In the case at hand, the axial lifting movement is advantageously made automatically with the rotation (due to the embodiment of the threads  102 - 1  and  102 - 2 ). 
         [0034]    In the alternative, the lower part  100 - 2  can also be connected to the upper part  100 - 1  by means of a bayonet closure, so that—when the bayonet closure is open—the lower part  100 - 2  is separated from the upper part  100 - 1  and the sweetening means  80 A can optionally be arranged in the recess  105 - 1  or in the recess  105 - 2 , before the lower part  100 - 2  is connected again to the upper part  100 - 1  by means of the bayonet closure. 
         [0035]    In a further alternative, the lower part  100 - 2  can be arranged on a guide, which provides for a guided relative movement of the lower part  100 - 2  relative to the upper part  100 - 1  (in each case between the position of the lower part  100 - 2  illustrated in  FIG. 1  and another position of the lower part  100 - 2 , said position making it possible to optionally arrange the sweetening means  80 A in the recess  105 - 1  or in the recess  105 - 2 . The guide can be a linear guide, for example. In the alternative, the lower part  100 - 2  can also be rotatably supported on a pivot axis, so that the lower part  100 - 2  can be moved in a rotation about the pivot axis relative to the upper part  100 - 1 . The pivot axis can thereby be oriented horizontally or vertically, for example. 
         [0036]      FIG. 2  shows a sectional view of a second exemplary embodiment of the milk-frothing apparatus  100  wherein the same reference numerals illustrate the same elements or elements acting in the same manner, as in  FIG. 1 . In addition to the first exemplary embodiment from  FIG. 1 , a first sweetening means inlet channel  15 , which leads into the hollow space  10 , is present in the case of the second exemplary embodiment according to  FIG. 2 . It is illustrated schematically that a storage container  20  for liquid sweetening means  80 B is connected to the other end of the first sweetening means inlet channel  15 . In response to a frothing process and the introduction of steam into the steam-inlet channel  11  associated therewith, a lower pressure is also generated in this first sweetening means inlet channel  15  due to the Venturi effect, which causes the liquid sweetening means  80 B to flow into the hollow space  10  through the first sweetening means inlet channel  15 . An early mixing of the components steam, milk, air, which are introduced or sucked in, respectively, as well as of the (liquid) sweetening means  80 B thus already takes place here. In a similar manner as in the first exemplary embodiment according to  FIG. 1 , this mixture subsequently reaches into the emulsion chamber  50 , wherein provision is made in this second exemplary embodiment according to  FIG. 2  at the emulsion chamber  50  for an additional second sweetening means inlet channel  16 , which leads into this chamber. Due to the fact that a noteworthy low pressure is not generated within the emulsion chamber  50 , provision is made for an active introducing device  21  for liquid sweetening means, advantageously a pump, which introduces liquid sweetening means  80 B from a storage container  20  through this second sweetening means inlet channel  16  into the interior of the emulsion chamber  50 , for transporting the liquid sweetening means  80 B through this second sweetening means inlet channel  16 . Analogously to the first exemplary embodiment from  FIG. 1 , a further mixing with the liquid sweetening means  80 B, which is introduced into the emulsion chamber  50 , then takes place here, before the mixture, that is, the sweetened milk froth comprising a fine and dense structure, is introduced into the connection channel  51  and is output through the outlet channel  70 . 
         [0037]    It goes without saying that, modeled after the second exemplary embodiment according to  FIG. 2 , it is also possible in each case to provide only one of the two sweetening means inlet channels  15 ,  16  with an assigned storage container  20  for liquid sweetening means, and, if necessary, with an introducing device  21 . This means that it goes without saying that it is likewise possible to introduce sweetening means  80  only into the hollow space  10  or only into the emulsion chamber  50 , respectively. 
         [0038]    In contrast to the second exemplary embodiment according to  FIG. 2 , not a liquid, but solid sweetening means  80 C is introduced into the interior of the emulsion chamber  50  in the third exemplary embodiment shown in  FIG. 3 , through the second sweetening means inlet channel  16 , which is also provided at that location. Instead of the storage container  20  for liquid sweetening means, provision is made for this purpose for a storage container  40  for solid, if necessary powdery sweetening means  80 C, which can be introduced into the interior of the emulsion chamber  50  by means of an introducing device  41 , where, analogously to the two above-described exemplary embodiments, a mixing with the sweetening means  80 C, which dissolves, if necessary, takes place. As in the case of the introducing device  21  for liquid sweetening means according to the second exemplary embodiment illustrated in  FIG. 2 , the introducing device  41  for solid, if necessary powdery sweetening means  80 C according to the third exemplary embodiment illustrated in  FIG. 3 , can be operated manually or can also work automatically. In particular in the case of an automatic embodiment, it is possible to add a predetermined quantity of sweetening means in a simple manner.