A method for preparing a beverage such as coffee from a capsule filled with an ingredient such as ground coffee and a beverage brewing machine for preparing a beverage from a capsule filled with an ingredient such as ground coffee

Abstract

A method for preparing a beverage such as coffee from a capsule filled with an ingredient such as ground coffee using a capsule-based single-serve beverage making machine comprising a brewing chamber having an inlet and an outlet, a. The method comprises prewetting the ingredient and letting flow a fluid such as water under pressure through the capsule for brewing the beverage. The pump is of a type which, in use, is operated by a AC-voltage wherein each cycle of the AC voltage causes the pump to make one stroke wherein a predetermined amount of liquid is released by the pump, the AC-voltage having a cycle time T. The method comprises the following steps: (c) feeding a fluid such as water under pressure by means of the pump and via the fluid connection and the inlet towards and into the capsule; (d) interrupting the pump for a time period ts, wherein ts lays in a time-interval of 0.02-0.9 seconds, preferably between 0.4-0.85 seconds, more preferably between 0.6 and 0.8 seconds and wherein ts= n1*T wherein n1 is an integer larger than 1; (e) resuming the operation of the pump for a time tr wherein tr is smaller than ts and tr=n2*T wherein n2 is an integer larger than 0 and smaller than n1; (f) repeating a combination of first step (d) and subsequently step (e) for N times wherein N is an integer larger than 1; and (g) after step (f) continuing the operation of the pump.

Description

[0001] Title: A method for preparing a beverage such as coffee from a capsule filled with an ingredient such as ground coffee and a beverage brewing machine for preparing a beverage from a capsule filled with an ingredient such as ground coffee

[0002] The present invention relates to a method for preparing a beverage such as coffee from a capsule filled with an ingredient such as ground coffee using a capsule-based single-serve coffee making machine comprising a brewing chamber having an inlet and an outlet, a pump and a fluid connection extending between the pump and the inlet, the method comprising prewetting the ingredient, opening the capsule on its outlet side under the influence of fluid pressure inside the capsule if the capsule is closed on its outlet side and letting flow a fluid such as water through the capsule for brewing the beverage.

[0003] The invention also relates to a beverage brewing machine for preparing a beverage such as coffee from a capsule filled with an ingredient such as ground coffee, the machine comprising a brewing chamber having an inlet and an outlet, a pump, a fluid connection extending between the pump and the inlet and a control circuitry for controlling the pump, wherein the machine is arranged for, in use, (a) placing the capsule into the brewing chamber such that the capsule is positioned in a fluid path extending in the brewing chamber from the inlet to the outlet and (b) providing at least one opening on an inlet side of the capsule if the capsule prior to step (a) is closed at its inlet side; wherein the machine is further arranged for prewetting the ingredient, opening the capsule on its outlet side under the influence of fluid pressure inside the capsule if the capsule is closed at its outlet side and letting flow a fluid such as water through the capsule for brewing the beverage.

[0004] Such a method and beverage brewing machine is known from EP 2001343 Bl. According to EP 2001343B1 a standard and non-expensive pump is used. The pump is used for prewetting the ingredient by means of a pressurised fluid and keeping the capsule pressurised (blooming phase of the prewetting), for opening the outlet side of the capsule by means of a pressurised fluid if the capsule is of a type closed at its outlet side prior to use and for brewing a beverage by means of an increased pressurised fluid. These different phases require different fluid pressures respectively. If the fluid pressure would be too high during prewetting there is a risk that the outlet side of the capsule is opened too early if the capsule is of a type closed at its outlet side such that the brewing process starts and the prewetting phase is early terminated. If the fluid pressure during the prewetting phase is too low, prewetting may not have been sufficient on the moment in time the outlet side of the capsule is opened by means of the increased fluid pressure and brewing follows. Alternatively if the fluid pressure during the prewetting phase is too low, prewetting may not have been sufficient on the moment in time the fluid starts flowing out of the capsule after the prewetting phase if the capsule is of a type which is open on its outlet side (for example because the capsule at its outlet side is provided with filtering paper and / or a perforated foil) before being used. During prewetting the interaction between the fluid and the ingredient may not result in optimal prewetting of the ingredient itself. Also, if the fluid pressure during the prewetting phase is too low the fluid in certain known types of the brewing chamber may bypass the capsule, which is not desired.

[0005] The object of the invention is to improve the known method and machine on at least one aspect.

[0006] The method according to the invention is characterized in that the pump is of a type which, in use, is operated by a AC-voltage wherein each cycle of the AC voltage causes the pump to make one stroke wherein a predetermined amount of liquid is released by the pump, the AC-voltage having a cycle time T, the method comprising in succession the following steps: (a) placing the capsule into the brewing chamber such that the capsule is positioned in a fluid path extending in the brewing chamber from the inlet to the outlet;

[0007] (b) providing at least one opening on an inlet side of the capsule if the capsule at its inlet side prior to step (a) is closed;

[0008] (c) feeding a fluid such as water under pressure by means of the pump and via the fluid connection and the inlet towards and into the capsule;

[0009] (d) interrupting the pump for a time period ts, wherein ts lays in a time-interval of 0.02-0.9 seconds, preferably between 0.4-0.85 seconds, more preferably between 0.6 and 0.8 seconds and wherein ts= nl*T wherein nl is an integer larger than 1;

[0010] (e) resuming the operation of the pump for a time tr wherein tr is smaller than ts and tr=n2*T wherein n2 is an integer larger than 0 and smaller than nl;

[0011] (f) repeating a combination of first step (d) and subsequently step (e) for N times wherein N is an integer larger than 1; and

[0012] (g) after step (f) continuing the operation of the pump wherein the capsule at its outlet side is opened under the influence of the pressure of the fluid in the capsule if the capsule is closed on its outlet side, wherein the beverage is brewed by means of an interaction between the ingredient and the fluid in the capsule, and wherein the beverage flows from the capsule via its outlet side and the beverage is released via the outlet of the brewing chamber.

[0013] The object of step (c) is to make the ingredient in the capsule wet and the object of steps (d)-(f) (referred to as blooming phase of the prewetting phase) is to keep the ingredient wet at a desired fluid pressure. Because of the selected type of pump the desired accurate pressure control (specifically in the prewetting phase during steps (d)-(f))) can be realised.

[0014] Specifically due to the selected values for ts and tr a balance between pressurised flow and interruption is obtained which contributed to a desired prewetting and blooming. During the steps (d)-(f) (referred to as blooming phase) the ingredient is wet and pressure is maintained around a desired level in the capsule. More specifically, the object of step (d) is to keep the ingredient wet and at rest with a certain fluid pressure during a certain desired length of time. The pressure may however slowly decrease during this step (d). The object of step (e) is to slightly increase the pressure in the capsule and maintain or bring back the pressure in the capsule at a desired level. Because N is larger than 1 a prewetting phase with slightly varying pressure in the capsule is obtained which also contributed to a desired prewetting. Preferably a desired type of prewetting is not only a surrounding of an ingredient particle such a ground coffee by fluid but also an absorption of the fluid into such an ingredient particle. A desired type of prewetting is also an interaction of the fluid with the majority of the ingredients in the capsule, preferably more than 50%, more preferably more than 70%. If there is a large penetration depth of the fluid into the capsule towards its outlet side this may come with the risk that -if the capsule is closed on its outlet side- the capsule is opened at its outlet side due to relatively high fluid forces acting on the outlet side. If there is a large penetration depth of the fluid into the capsule towards its outlet side this may come with the risk that -if the capsule is open on its outlet side - an undesired amount of fluid may flow from the capsule’s outlet side during the prewetting phase. Due to a value of tr being smaller than ts the early opening of the outlet side can be avoided. Due to a value of N > 1 a sufficient penetration depth of the fluid towards the outlet side can be obtained.

[0015] Preferable nl, n2 and N are selected such that during prewetting in steps (c)-(f) the capsule is not opened at its outlet side given the value of T and the amount of fluid which is released during one stroke of the pump.

[0016] Preferably ts lays in a time-interval of 0.75-0.85 seconds. The advantage is that the forces acting on the outlet side can remain sufficiently small to avoid early opening of the capsule. Preferably tr= 0.01-0.04 seconds. Again the advantage is that the forces acting on the outlet side may remain sufficiently small to avoid early opening of the capsule.

[0017] Preferably T lays in the range of 0.01-0.04 seconds, more preferably T=0.02 seconds or 0.0167 seconds. The latter are values which can practically be derived from existing grids (such as in the EU or US).

[0018] Preferably nl= 20-45, more preferably 30-44, more preferably 35-40 such as 30, 35 or 40. Furthermore preferably n2 = 1-4, preferably 1. The selection of these values provide the advantages of the above discussed values of ts and tr. As explained the values of ts and tr together with the amount of fluid which is pumped during tr can be controlled very accurately due to the selection and the use of the type of pump as discussed. Preferably in step (c) a predetermined amount of liquid is pumped towards and into the capsule. This amount is sufficient for pre-wetting the ingredient in the capsule. It is also sufficient for building up a required pressure at the inlet of the brewing chamber. At the same time it is avoided that the capsule is opened under the influence of liquid pressure if the capsule is of a type closed at its outlet side before being used. Also it is avoided that liquid flows out of the capsule should the capsule be of a type which is open at its outlet side prior to use.

[0019] Preferably the pump is activated for a time ti, wherein ti lays in the range of 2-15 seconds, preferably 8-11 seconds. The time ti is sufficient for building up a required pressure at the inlet of the brewing chamber for subsequently starting step (d). Preferably in step (c) the pump makes 100-750, more preferably 400-550 strokes, wherein preferably during one stroke the pump pumps 0.01-0.15 ml, preferably 0.02 ml liquid. The inner volume of the capsule (this is the volume which may be filled with the ingredient and the liquid) may be in the range of 12-26 ml.

[0020] N may lay in the range of 1-80, preferably 1-30, more preferably in the range of 5-15. Steps (d)-(f) may take 3-35 seconds, preferably 6-20 seconds, more preferably 8-12 seconds. This proofs to be a length of time to allow an effective prewetting of the ingredient. During steps (d)-(f) the pressure at the inlet side of the capsule may be 2-6 bar, preferably 2, 5-4.5 bar. This proofs an effective pressure to be used in the prewetting phase. Furthermore it is preferred that during step (g) the pressure raises relative to the pressure at the inlet side of the capsule during steps (d)-(f), preferably to 5-20 bar, more preferably to 7-15 bar. This provides a good extraction of the ingredient in the form of ground coffee wherein a balanced taste and crema layer can be obtained if the beverage is collected in a cup. Preferably during step (g) the pump is operated uninterrupted. This means that during step (g) it operates preferably at full power.

[0021] The machine according to the invention is characterized in that the pump is of a type which, in use, is operated by a AC-voltage generated by the control circuitry wherein each cycle of the AC voltage causes the pump to make one stroke wherein a predetermined amount of liquid is released by the pump, the AC-voltage having a cycle time T, the control circuitry being arranged such that in use the pump is controlled by the AC voltage as follows:

[0022] (c) by means of the pump a fluid such as water is fed under pressure via the fluid connection and the inlet towards and into the capsule;

[0023] (d) the pump is interrupted for a time period ts, wherein ts lays in a time-interval of 0.02-0.9 seconds, preferably between 0.4-0.85 seconds, more preferably between 0.6 and 0.8 seconds and wherein ts= nl*T wherein nl is an integer larger than 1;

[0024] (e) the operation of the pump is resumed for a time tr wherein tr is smaller than ts and tr=n2*T wherein n2 is an integer larger than 0 and smaller than nl;

[0025] (f) a combination of first step (d) and subsequently step (e) is repeated for N times wherein N is an integer larger than 1; and (g) after step (f) the operation of the pump is continued so that the capsule is opened at its outlet side under the influence of fluid pressure if the capsule is closed at its outlet side during step (a) and a beverage is brewed from the interaction between the fluid and the ingredient wherein the beverage flows from the capsule via the outlet side and is released via the outlet of the brewing chamber.

[0026] If a capsule is used which is closed at its outlet side a desired prewetting can be performed by the machine with a reduced risk that the capsule is opened early for the same reasons as discussed above for the method. The machine can however also be used for prewetting the ingredient in a capsule from which the outlet side is already open before the capsule is loaded into the machine. In that case the desired type of prewetting as discussed above (for example penetration depth and / or, absorption of fluid into the ingredient) can also be realised with the same machine. The machine can also be used with a capsule which is already open at its inlet side before being loaded into the machine.

[0027] The invention will now be discussed further with reference to the attached non limiting drawings wherein:

[0028] Figure 1 shows schematic an embodiment of a system according to the invention comprising an embodiment of a beverage brewing machine according to the invention loaded with a capsule to carry out a method according to the invention;

[0029] Figure 2 shows schematic a pressure-time diagram wherein the pressure is a pressure of water at position P in Figure 1 during use of the beverage brewing machine of figure 1 with a first type capsule as shown in figure 1;

[0030] Figure 3 shows schematic a pressure-time diagram associated with a capsule of the second type and a modified version of the beverage brewing machine of figure 1 so that the machine can be loaded with the capsule of the second type wherein the pressure is a pressure of water at position P in Figure 1 during use of the beverage brewing machine with the second type capsule; and

[0031] Figure 4 shows a capsule of the first type and a capsule of the second type.

[0032] In figure 1 a system according to the invention is provided with reference number 1. The system is provided with a beverage preparation machine 2 for preparing a beverage from a capsule 4 filled with an ingredient such as ground coffee 6. The machine 2 comprises a brewing chamber 8 having an inlet 10 and an outlet 12. Furthermore a spout 13 is provided for collecting a beverage flowing through the outlet 12. The machine further comprises a pump 14 and a fluid connection 16 extending between an outlet side of the pump and the inlet 10. The machine comprises in this example a reservoir 18 which can be filled with water and a further fluid connection 20 extending between the reservoir and an inlet side of the pump 14. Heating means 17 are provided for heating a fluid flowing through the fluid connection 16. The machine is further provided with a control circuitry 21 for controlling the pump 14. Also the machine comprises in this example a control-panel 22 for providing instructions to the control circuitry by a user. The pump is of a type which, in use, is operated by a AC-voltage signal generated by the control circuitry 21 wherein each cycle of the AC voltage signal causes the pump to make one stroke wherein a predetermined amount of liquid is released by the pump. The AC-voltage has a cycle time (also known as repetition time or period) T. In this example T=0.02 seconds. The pump may for example be a well-known positive displacement pump. The pump which may be used is of a type also known by the name vibration pump, vibe pump and solenoid pump.

[0033] In this example the brewing chamber 8 comprises an enclosing member 23 for being loaded with the capsule 4 and a plate 24 for closing the enclosing member, the plate being provided with relief elements 26 for opening the capsule on its outlet side under the influence of fluid pressure in the capsule. In this example the outlet 12 is formed by a plurality of openings in the plate. The enclosing member 23 is provided with cutting means 30 for opening the capsule at its inlet side 32. The inlet side and the outlet side of the capsule are defined to be on the outside of the capsule.

[0034] In this example the capsule 4 comprises a capsule body 34 sealed with a lid 36 of the capsule. The capsule body 34 comprises in this example a base 38, a sidewall 40 and a flange 42. The lid 36 is sealed to the flange 42 wherein the base 38 forms the inlet side 32 of the capsule and the lid 36 forms the outlet side 28 of the capsule. The capsule body may be made from a metal such as aluminium, an aluminium alloy, tin, stainless steel etc. The body may also be made from a biodegradable material or a plastic. Laminates comprising combinations of at least two of a metal layer, biodegradable layer and a plastic layer are also not ruled out. The lid may also be made from the same selection of materials as discussed for the capsule body. In this example the capsule body is made from aluminium, optionally provided with a lacquer layer. The lid is made from aluminium. Optionally the lid is provided with a lacquer layer. The lid is sealed to the capsule body to provide an hermetically sealed capsule. The inner volume of the capsule (this is the volume which may be filled with the ingredient and the liquid) may be in the range of 12-26 ml.

[0035] In this example the enclosing member 23 and the plate 24 can be moved away from each other for positioning the capsule in the enclosing member 22. Subsequently the enclosing member and the plate can be moved towards each other. As a result the cutting means will cut open the base 38 of the capsule. The enclosing member will provide a fluid sealing contact with the flange of the capsule in a known manner. The plate including its relief elements may contact the lid of the capsule (prior to brewing or during brewing) if the plate and the enclosing member have been moved towards each other to form a closed brewing chamber comprising the capsule 4. The opening and closing of the brewing chamber may be performed manually in a known manner, for example by means of moving a pivotable lever which is mechanically connected to a mechanical closing mechanism. Alternatively opening and closing of the brewing chamber may be carried out by means of an electromotor actuated by the control circuitry 21 if for example a button of the control panel 22 is operated. The enclosing member may be provided with well-known hydraulic closing means for (further) closing the brewing chamber by (further) moving a free edge of the enclosing member (the edge of the enclosing member which faces the plate) and the plate towards each other. Such a hydraulic closing means is known from EP 2068684 Al and incorporated by reference in this application.

[0036] The working of the machine for preparing a beverage is as follows. In use, in a step (a) the capsule is placed into the brewing chamber such that the capsule is positioned in a fluid path extending in the brewing chamber from the inlet to the outlet. Subsequently in a step (b) at least one opening is provided in the capsule on an inlet side of the capsule. In this example the opening is made by the cutting means 30 in the form of knives as discussed above. Step (a) and (b) have already been discussed above in more detail.

[0037] The user activates the machine by activating a predetermined button of the control panel. In response, the control circuitry 22 controls pump 14 via the control line 21a by means of the AC voltage as follows: In a step (c) by means of the pump 14 water under pressure is fed from the reservoir 18 via the fluid connections 20 and 16 and the inlet 10 towards and into the capsule 4. As a result of the action of the pump the water pressure at point P in figure 1 will change as is shown in figure 2. Also in response to the activation by the user the control circuitry controls the heating means 17 via control line 21b so that the water flowing through the fluid connection 20 is heated to for example 90 degrees Celsius. Other values are also possible. In figure 2 step (c) starts at t=0 seconds and ends at t=8 seconds. It is noted that in this document a value of fluid pressure stream downwards of the pump is the pressure of fluid which can be measured outside the capsule close to the inlet of the brewing chamber and thereby close to the inlet side of a capsule loaded into the brewing chamber.

[0038] In this example such pressure values are defined at position P. It is assumed that this is the pressure at the inlet side of the capsule.

[0039] In a step (d) the pump is interrupted for a time period ts, wherein ts lays in a time-interval of 0.02-0.9 seconds, preferably between 0.4-0.85 seconds, more preferably between 0.6 and 0.8 seconds and wherein ts= nl*T wherein nl is an integer larger than 1. In this example nl=80. This means ts=1.6 seconds

[0040] In a step (e) the operation of the pump is resumed for a time tr wherein tr is smaller than ts and tr=n2*T wherein n2 is an integer larger than 0 and smaller than nl. In this example n2=2 so that tr=0.04 seconds. It also follows that step (d) plus step (e) takes 1.64 seconds

[0041] In a step (f) a combination of first step (d) and subsequently step (e) is repeated for N times wherein N is an integer larger than 1. In this example N=4 so that all steps (d) and (e) take 5*1.64 seconds. This makes 8.28 seconds.

[0042] In a step (g) after step (f) the operation of the pump is continued by submitting the uninterrupted AC voltage signal to the pump. This means the pump operates at full power within the machine. Thereby the fluid pressure in the capsule will increase so that the lid is pressed to the relief elements 26 and will tear open. As a result the capsule is opened at its outlet side under the influence of fluid pressure and a beverage is brewed from the interaction between the fluid and the ingredient. The beverage flows from the capsule via the outlet side and is released via the outlet of the brewing chamber via a spout 13. The above discussed control of the pump has the following result.

[0043] In this example in step (c) the pump is operated for 6 seconds. This period is indicated by arrow c in figure 2. Thus during this 6 seconds the pump receives 50 control pulses from the AC voltage signal in one second and thereby in total 6*50=300 control pulses. Each pulse has as an effect that the pump makes one stroke as discussed above. In step (c) the pump submits 300 times the predetermined amount of water relating to one stroke towards the capsule. The predetermined amount of liquid (water in the example) relating to one stroke is in this example 0.02 ml. As a result about 6 ml of water is pumped towards and into the capsule and the average pressure at position P increases. Because the pump makes 50 strokes per second during step (c) the pressure at position P has the character of a pulsating pressure with a certain bandwidth. After step (c) the ingredient in the capsule has become wet due to the water pumped towards and into the capsule. Because the inner volume of the capsule is in this example about 20 ml, the ingredient becomes wet without the capsule tearing open on its outlet side.

[0044] Step (d) starts after t=6 seconds.

[0045] In this example ts=1.6 seconds, T=0,02 seconds (50 Hz) and nl=30 and n2=2. This means that the pump is interrupted in step (d) for 1.6 seconds and that in step (e) the pump is resumed for tr= 0.04 seconds. Thus in step (e) the pump makes only one stroke. As shown in figure 2 during the first step (d), indicated with dl the pressure in the capsule slightly decreases and no water is fed into the capsule. Because the pump is in rest the pressure at position P has no longer a pulsating character. During the first step (e), indicated in figure 2 with el, the amount of water related to one stroke is submitted towards the capsule with the result that after the first step (e) the pressure is slightly increased again. Thus a combination of step (d) and (e) has as a result that the pressure on position P and thereby in the capsule is maintained and water remains in the capsule without however the lid of the capsule tearing open on the relief elements 26 because the water pressure in the capsule remains low enough to prevent tearing. A combination of step (d) and (e) has as a result that the ingredient is prewetted during step (d) and step (e), thus during 1.64 seconds.

[0046] After first step (e) the pump is interrupted again during a second step (d) indicated with d2. During this period the pressure again slightly decreases. Subsequently after the second step (d) the pump is activated again with one stroke in a second step (e) indicated with e2. Again after the second step (e) the pressure is slightly increased. Again during the combination of second step (d) and second step (e) the ingredient of the capsule is prewetted during 0.82 seconds wherein the lid stays intact.

[0047] In this example after first step (d) and (e) this sequence is repeated N=4 times. Thus 5 combinations of steps (d) and (e) and executed during 5 *0.164 = 8.2 seconds. The result is that the ingredient is prewetted during 8.2 seconds while the lid remains intact. The pressure on position P and thereby the pressure in the capsule remains in this example at a level of about 3.5 bar, which is a favourable pressure for prewetting the ingredient. After step (f) the operation of the pump is resumed in step (g) without any interruption for brewing the beverage. Thus the pump operates at full power in step (g). The pressure on position P and thereby in the capsule will increase. Again the pressure has a pulsating character during step (g). Once the pressure reaches about 8 bar the water pressure pushes the lid 36 to the plate 24 with such a force that the lid tears on the relief elements 26. The opening of the lid occurs in this example at about t=16 seconds Thus from this moment water starts to flow into and out the capsule. The pressure on position P will further increase to a level above 8 bar, for example to 12 bar. Thus within the period associated with step (g) water flows through the capsule for preparing the beverage. The beverage flows via openings 12 in the plate and the spout 13 into a container such as a cup 44. The total duration of step (g) is in this example 40 seconds. This means that in this period about 40 ml beverage will be produced (0.02 (ml) * 50 (Hz) *40 (seconds). Due to the prewetting of the ingredient during 8.2 seconds at a pressure level of about 3.5 bar the beverage will have excellent tasting characteristics. As discussed nl, n2 and N are selected such that during prewetting in steps (d)-(f) the capsule is not opened at its outlet side given the value of T and the amount of fluid which is pumped by the pump during one stroke. Also during steps (d)-(f) prewetting of the ingredient can take place during a sufficient length of time at a favourable pressure. Other values of the variables discussed above can however be selected.

[0048] According to a more general approach the following examples may be applied too. T may for example be 0.0167 seconds so that the AC voltage comprises 60 control pulses in one second. The value of ts may lay in a timeinterval of 0.6-0.8 seconds. The value of tr may lay in an interval of 0.01- 0.04 seconds. T may lay in the range of 0.01-0.04 seconds.

[0049] The value of nl may lay in the interval of = 20-45. The value of n2 may lay in the interval of 1-4. N may lay in the range of 1-80, preferably 1-30, more preferably in the range of 5-15. Steps (d)-(f) (meaning all steps (d)-(f) in combination) may take 3-35 seconds, preferably 6-20 seconds, more preferably 8-12 seconds. During steps (d)-(f) in combination the pressure at the inlet side of the capsule may be 2-6 bar, preferably 2.5-4.5 bar. In step (c) the pump may be activated for a time ti, wherein ti lays in the range of 2- 10 s, preferably 8-1 Is. In step (c) the pump may make 100-750 strokes, preferably 400-550 strokes. During steps (d)-(f) the fluid pressure may lay in the range of 2-6 bar, preferably 2.5-4.5 bar. During step (g) the pressure at the inlet side of the capsule may raise relative to the pressure at the inlet side of the capsule during steps (d)-(f), preferably to 5-20 bar, preferably to 7-15 bar. During one stroke the pump may pump 0.01-0.15 ml liquid. During step (g) 15-400 ml, preferably 20-250 ml, more preferably 20-120 ml beverage may be brewed.

[0050] In the above example the brewing chamber was loaded with an aluminium hermetically sealed capsule filled with ground coffee. The ingredient may however also comprise other substances such as tea. Also the capsule may be provided, prior to use, with openings on its inlet side and / or outlet side. For example if the capsule is open on its inlet side and outlet side the cutting means may but need not make additional openings on the capsule’s inlet side upon loading in the brewing chamber. In that case during step (c) water will also enter the capsule wherein some water may also flow out of the capsule via its open outlet side. Nevertheless the ingredient will become wet. Thus during steps (d)-(f) there will be little flow of water through the capsule and prewetting takes place, in the above example this will take 11.48 seconds. Subsequently during step (g) 40 ml beverage will be produced within 40 seconds similar as discussed above for the aluminium capsule.

[0051] In a special embodiment the machine is provided with a flowmeter 15 for measuring the flowrate of the liquid which is pumped by the pump towards the inlet 10 of the brewing chamber 8. The flowmeter is communicatively connected to the control circuitry by means of a control line 15a for submitting, in use, a signal to the control circuitry representing the measured flowrate. In this case the flowmeter 15 measures the flowrate of fluid flowing through the further fluid connection 20. This equals the flowrate of fluid flowing through the fluid connection 16 towards the inlet.

[0052] Alternatively the flowmeter 15 could have been positioned stream upwards of the pump to measure the flowrate of fluid flowing through the fluid connection 16. The control circuitry may be arranged, in use, to control, the pump based on the information provided by the flowmeter such that in steps (c)-(g) a predetermined amount of fluid is pumped by the pump towards the inlet of the brewing chamber (thus the flowmeter is part of a feedback loop). Thus the control circuitry may integrate at any time the measured flowrate to calculate the amount of fluid which has flown towards the inlet 10 for preparing a beverage. Thus this means that although during steps (d)-(f) the flow of fluid is purely time controlled without using the information provided by the flowmeter (also referred to as dead reckoning), the overall amount of fluid pumped by the pump is measured by the flowmeter and used by the control circuitry to control the total amount of fluid pumped for preparing a beverage. The use of dead reckoning for carrying out steps (d)-(f) is due to the low flow-rate during these steps more accurate than using the flowmeter to control these steps. Additionally or alternatively the control circuitry is arranged to control the pump in step (c) based on the information provided by the flowmeter, such that a predetermined amount of fluid is pumped by the pump towards the inlet of the brewing chamber (again the flowmeter and the control circuitry form a feedback loop). Thus in that case the amount of fluid which is used for prewetting is based on a measurement of the flowmeter. Additionally or alternatively the control circuitry is arranged for controlling the pump based on the information provided by the flowmeter such that in step (g) a predetermined amount of fluid is pumped by the pump towards the inlet of the brewing chamber (again the flowmeter and the control circuitry form a feedback loop). Alternatively steps (c)-(g) are each time controlled without the use of a feedback loop wherein the flowmeter may thus be deleted.

[0053] In the above examples the control circuitry is arranged such that, in use, in each of the carried out steps (d) nl has one and the same value. In this example nl=30. In the above example the control circuitry is also arranged such that, in use, in each of the carried out steps (e) n2 has one and the same value. In this example n2=2. In table 1 below the characteristics of steps (d)-(f) with respect to the value of nl and n2 in the example are summarised. Table 1: However according to the invention it is also possible that the control circuitry is arranged such that, in use, in at least two steps (d) of the carried out steps (d) nl has different values respectively. Also or alternatively it is also possible that the control circuitry is arranged such that, in use, in at least two steps (e) of the carried out steps (e) n2 has different values respectively. This is shown in a second example below. The second example is shown in table 2, wherein N=3.

[0054] The selection of mutually different steps (d) and mutually different steps (e) respectively, can be utilised to optimise in cup quality parameters such as crema quality & extraction yield. Additionally such selection can also be used to shift taste profile by influencing the density / porosity of the ingredient bed in the capsule and reducing interstitial space between the ingredient particles so as to change the balance between primary and secondary extraction in case the ingredient is ground coffee. Table 2:

[0055] In the second example in the first sequence of steps (d) and (e) nl=10. In the second sequence of steps (d) and (e) (this is the first time that steps (d) and (e) are repeated in step (f)) nl=30. In the third sequence of steps (d) and (e) (this is the second time that steps (d) and (e) are repeated in step (f)) nl=10.

[0056] In the fourth sequence of steps (d) and (e) (this is the third time that steps (d) and (e) are repeated in step (f))) nl=30. In the second example in each of the four sequences of steps (d)+(e) n2=l. In the second example n2 could also have other values such as for example n2 = 2 , 3 or 4.

[0057] In the second example the sequence with nl=10 may help -in a well- known type of brewing chamber (the type wherein the forces for providing a sealing interface between the capsule and the brewing chamber increase if the fluid pressure in the brewing chamber increases)- to enable a better initial seal between capsule and brewing chamber due to a higher pressure level in the brewing chamber. The result is less leakage around the seals and when there is no or less leakage the pressure in the capsule can be maintained high over the whole blooming phase (steps (d)-(f)). As the pressure in the capsule during the blooming can be maintained at a high level also the opening of the capsule on its outlet side (for example by topfoil burst) is more powerful (i.e. a higher burstflow occurs) leading to more ingredient bed compaction within the capsule and reducing channelling in the ingredient bed. Summarized this process can create a higher quantity of coffee crema and also a higher solid levels. In the second example the control circuitry is arranged such that, in use, in at least two steps (d) of the carried out steps (d) nl has different values respectively. As explained above also or alternatively it is also possible that the control circuitry is arranged such that, in use in at least two steps (e) of the carried out steps (e) n2 has different values respectively. This is demonstrated in a third example according to table 3, wherein N=3

[0058] Table 3:

[0059] In the third example in the first sequence of steps (d) and (e) nl=10 and n2=4. In the second sequence of steps (d) and (e) (this is the first time that steps (d) and (e) are repeated in step (f)) nl=30 and n2=l. In the third sequence of steps (d) and (e) (this is the second time that steps (d) and (e) are repeated in step (f)) nl=10 and n2=3. In the fourth sequence of steps (d) and (e) (this is the third time that steps (d) and (e) are repeated in step (f))) nl=30 and n2=l. Other variations are possible, for example the third example is changed such that nl has the same value in each of the four sequences such that only n2 may have different values in different sequences of steps (d) and (e)..

[0060] To show the variations of possibilities a fourth example is shown in Table 4. Table 4

[0061] In each of the above examples in step (c) the pump may be continuously operated at full power. It is however also possible that the control circuitry is arranged such that, in use, in step (c) the pump is at least one time interrupted. Thus for example in a first portion of step (c) the pump is operated continuously wherein in a following second portion of step (c) the pump is at least one time interrupted. Such variations also fall within the scope of the invention. It is also not ruled out that between step (c) and the first step (d) the pump is operated, optionally with at least one interruption. It is also not ruled out that between step (f) and step (g) the pump is operated, optionally with at least one interruption.

[0062] In the above examples a single size capsule can be loaded into the brewing chamber. The brewing chamber of the machine according to figure 1 may however also be of a type which can be loaded with different sized capsules. Such a loading chamber and beverage machine is for example known from WO 2018 / 026272 which document is incorporated by reference.

[0063] Thus the brewing chamber may be arranged to be selectively loaded with capsule of a first type 4 and a capsule of a second type 4’; see figure 4.

[0064] The capsule of the first type and the capsule of the second type each have in the example such as shape that each capsule has a largest diameter D, D’ at its outlet side. Also in the example, the outer volume of the capsule of the second type is larger than the outer volume of the capsule of the first type. The largest diameter D’ of the capsule of the second type is larger than the largest diameter D of the capsule of the first type. Further an inner volume of the capsule of the second type is larger than an inner volume of the capsule of the first type and wherein preferably the capsule of the first type and the capsule of the second type have a similar shape. The machine may comprise at least one sensor for generating at least one signal which indicates whether a capsule of the first type or a capsule of the second type is present in the brewing chamber, wherein, in use, the signal is submitted to the control circuitry for selecting at least the duration of step (g). Please note the at least one signal may be such that it is only generated if a capsule of the second type is detected. If no capsule of the second type is detected by means of the at least one sensor (so that the at least one signal is not generated) it may be assumed that the machine is loaded with a capsule of the first type if a user pushes a button to start brewing a beverage. This also falls under the wording that the at least one signal indicates (by means of its presence or absence) whether a capsule of the first type or a capsule of the second type is present in the brewing chamber. Alternatively it is also possible that it is indicated by the at least one signal that a capsule of the first type or a capsule of the second type is loaded in the brewing chamber (and thus that the brewing chamber is not empty) in combination with information about whether a capsule of the first type or a capsule of the second type is loaded in the brewing chamber if the brewing chamber is not empty. In that case the at least one signal can also indicate a status wherein the brewing chamber is empty. In that case the control circuitry may be arranged such that if the at least one sensor detects that the brewing chamber is empty and a user operates a button for preparing a beverage the pump is not activated. If the capsule of the first type is detected the duration of step (g) and / or step (c) may for example be smaller than the duration of step (g) if the capsule of the second type is detected. Steps (c) - (f) or (d) - (f) may be but need not be the same for both types of capsules. For example it may be that the value of N if the capsule of the first type is detected is smaller than the value of N if the capsule of the second type is detected. For figure 2 the discussed aluminium hermetically sealed capsule 4 is considered as the first capsule. In figure 3 an example is given for the use of a second type capsule, also made from aluminium and hermetically sealed. In that case the second type of capsule is used in the machine according to figure 1 wherein however the brewing chamber is modified so that it can also be loaded with the second type capsule in addition to the first type capsule. The inner volume of the second type capsule is for example twice the inner volume of the first type capsule, e.g. 40 ml. In figure 3 step (c) takes about 12 seconds, steps (d)-(f) take about 10 seconds (about same prewetting time as for the first type capsule) and step (g) takes about 65 seconds. Because as for figure 2 T=0.02 and one stroke of the pump corresponds again to 2 ml, it follows that about 65 ml beverage is prepared during step (g). Further for figure 3 nl, n2 and N which determine the prewetting process is the same as for figure 2.

[0065] In each case the capsule may however also be a well-known coffee pad comprising two foils welded to each other near its edges which are closed in itself and wherein the foils may be made from filtering paper and / or plastic and / or aluminium. Also the positions of the pump 14 and the heating means 17 may be interchanged so that the fluid which enters the pump is heated first by the heating means.

[0066] In the above example the fluid used is still water. However other fluids such as sparkling water, slightly salted water etc. may also be used.

Claims

CLAIMS1. A method for preparing a beverage such as coffee from a capsule filled with an ingredient such as ground coffee using a capsule-based single-serve beverage making machine comprising a brewing chamber having an inlet and an outlet, a pump and a fluid connection extending between the pump and the inlet, the method comprising prewetting the ingredient, opening the capsule on its outlet side under the influence of fluid pressure inside the capsule if the capsule is closed on its outlet side and letting flow a fluid such as water under pressure through the capsule for brewing the beverage, characterized in that the pump is of a type which, in use, is operated by a AC-voltage wherein each cycle of the AC voltage causes the pump to make one stroke wherein a predetermined amount of liquid is released by the pump, the AC-voltage having a cycle time T, the method comprising in succession the following steps:(a) placing the capsule into the brewing chamber such that the capsule is positioned in a fluid path extending in the brewing chamber from the inlet to the outlet;(b) providing at least one opening on an inlet side of the capsule if the capsule at its inlet side prior to step (a) is closed;(c) feeding a fluid such as water under pressure by means of the pump and via the fluid connection and the inlet towards and into the capsule;(d) interrupting the pump for a time period ts, wherein ts lays in a time-interval of 0.02-0.9 seconds, preferably between 0.4-0.85 seconds, more preferably between 0.6 and 0.8 seconds and wherein ts= nl*T wherein nl is an integer larger than 1;(e) resuming the operation of the pump for a time tr wherein tr is smaller than ts and tr=n2*T wherein n2 is an integer larger than 0 and smaller than nl;(f) repeating a combination of first step (d) and subsequently step (e) for N times wherein N is an integer larger than 1; and(g) after step (f) continuing the operation of the pump so that the capsule at its outlet side is opened under the influence of the pressure of the fluid in the capsule if the capsule is closed on its outlet side, the beverage is brewed by means of an interaction between the ingredient and the fluid in the capsule, the beverage flows from the capsule via its outlet side and the beverage is released via the outlet of the brewing chamber.

2. The method according to claim 1, wherein nl, n2 and N are selected such that during prewetting in steps (c)-(f) if the capsule is closed on its outlet side in step (a) the capsule is not opened at its outlet side given the value of T and the amount of fluid which is released during one stroke.

3. The method according to any preceding claim, wherein tr= 0.01-0.04 seconds.

4. The method according to any preceding claim, wherein T lays in the range of 0.01-0.04 seconds, preferably wherein T=0.02 seconds or T=0.0167 seconds.

5. The method according to any preceding claim, wherein nl= 20-45, preferably 30, 35 or 40.

6. The method according to any preceding claim wherein n2 = 1-4, preferably 1.

7. The method according to any preceding claim wherein N lays in the range of 1-80, preferably 1-30, more preferably 5-15.

8. The method according to any preceding claim wherein steps (d)-(f) take 3-35 seconds, preferably 6-20 seconds, more preferably 8-12 seconds.

9. The method according to any preceding claim wherein during steps (d)-(f) the fluid pressure at the inlet side of the capsule lays in the range of 2-6 bar, preferably 2.5-4.5 bar.

10. The method according to any preceding claim wherein during step (g) the pressure at the inlet side of the capsule raises relative to the pressure at the inlet side of the capsule during steps (d)-(f), preferably to 5-20 bar, more preferably to 7-15 bar.

11. The method according to any preceding claim wherein in step (c) the pump is activated for a time ti, wherein ti lays in the range of 2-15 seconds, preferably 8-11 seconds and / or wherein in step (c) a predetermined amount of liquid is pumped towards and into the capsule.

12. The method according to claims 4 and 11, wherein in step (c) the pump makes 100-750, preferably 400-550 strokes.

13. The method according to any preceding claim wherein during one stroke the pump pumps 0.01-0.15 ml, preferably 0.02 ml liquid.

14. The method according to any preceding claim wherein during step (g) 15-400 ml, preferably 20-250 ml, more preferably 20-120 ml beverage is brewed.

15. The method according to any preceding claim wherein during step (g) the pump is operated uninterrupted.

16. The method according to any preceding claim wherein the inner volume of the capsule is in the range of 12-26 ml.

17. The method according to any preceding claim wherein in steps (c)-(g) and / or step (c) and / or step (g) a predetermined amount of liquid is pumped towards the inlet of the capsule.

18. The method according to any preceding claim wherein in each of the carried out steps (d) nl has one and the same value and / or wherein in each of the carried out steps (e) n2 has one and the same value.

19. The method according to any preceding claim wherein in at least two steps (d) of the carried out steps (d) nl has different values respectively and / or wherein in at least two steps (e) of the carried out steps (e) n2 has different values respectively.

20. The method according to any preceding claim wherein in step (c) the pump is operated continuously or wherein in step (c) the pump is at least one time interrupted.

21. A beverage brewing machine for preparing a beverage such as coffee from a capsule filled with an ingredient such as ground coffee, the machine comprising a brewing chamber having an inlet and an outlet, a pump, a fluid connection extending between the pump and the inlet and a control circuitry for controlling the pump, wherein the machine is arranged for, in use, (a) placing the capsule into the brewing chamber such that the capsule is positioned in a fluid path extending in the brewing chamber from the inletto the outlet and (b) providing at least one opening on an inlet side of the capsule if the capsule prior to step (a) is closed at its inlet side; wherein the machine is further arranged for prewetting the ingredient, opening the capsule at its outlet side under the influence of fluid pressure inside the capsule if the capsule is closed on its outlet side and letting flow a fluid, such as water through the capsule for brewing the beverage, characterized in that, wherein the pump is of a type which, in use, is operated by a AC- voltage generated by the control circuitry wherein each cycle of the AC voltage causes the pump to make one stroke wherein a predetermined amount of liquid is released by the pump, the AC-voltage having a cycle time / repetition time T, the control circuitry being arranged such that in use the pump is controlled by the AC voltage as follows:(c) by means of the pump a fluid such as water is fed under pressure via the fluid connection and the inlet towards and into the capsule;(d) the pump is interrupted for a time period ts, wherein ts lays in a time-interval of 0.02-0.9 seconds, preferably between 0.4-0.85 seconds, more preferably between 0.6 and 0.8 seconds and wherein ts= nl*T wherein nl is an integer larger than 1;(e) the operation of the pump is resumed for a time tr wherein tr is smaller than ts and tr=n2*T wherein n2 is an integer larger than 0 and smaller than nl;(f) a combination of first step (d) and subsequently step (e) is repeated for N times wherein N is an integer larger than 1; and(g) after step (f) the operation of the pump is continued so that the capsule is opened at its outlet side under the influence of fluid pressure if the capsule is closed at its outlet side during step (a) and a beverage is brewed from the interaction between the fluid and the ingredient wherein the beverage flows from the capsule via the outlet side and is released via the outlet of the brewing chamber.

22. The machine according to claim 21, wherein nl, n2 and N are selected such that during prewetting in steps (c)-(f) the capsule is not opened at its outlet side if the outlet of the capsule is still closed during step (a) and given the value of T and the amount of fluid which is released during one stroke.

23. The machine according to any claim 21 or 22, wherein tr= 0.01-0.04 seconds.

24. The machine according to any preceding claims 21-23, wherein T lays in the range of 0.01-0.04 seconds, preferably wherein T=0.02 seconds or T=0.0167 seconds.

25. The machine according to any preceding claims 21-24, wherein nl= 20-45, preferably 30, 35 or 40.

26. The machine according to any preceding claims 21-25, wherein n2 = 1-4, preferably 1.

27. The machine according to any preceding claims 21-26, wherein N lays in the range of 1-80, preferably 1-30, more preferably 5-15.

28. The machine according to any preceding claims 21-27, wherein steps (d)-(f) take 3-35 seconds, preferably, 6-20 seconds, more preferably 8-12 seconds.

29. The machine according to any preceding claims 21-28, wherein during steps (d)-(f) the pressure at the inlet side of the capsule is 2-6 bar, preferably 2.5-4.5 bar.

30. The machine according to any preceding claims 21-29, wherein during step (g) the pressure at the inlet side of the capsule raises relative to the pressure at the inlet side of the capsule during steps (d)-(f), preferably to 5- 20 bar, more preferably to 7-15 bar.

31. The machine according to any preceding claims 21-30, wherein in step (c) the pump is activated for a time ti, wherein ti lays in the range of 2-15 seconds, preferably 8-llseconds and / or wherein in step (c) a predetermined amount of liquid is pumped towards and into the capsule..

32. The machine according to claims 24 and 31, wherein in step (c) the pump makes 100-750, preferably 400-550 strokes.33 The machine according to any preceding claims 21-32, wherein during one stroke the pump pumps 0.01-0.15 ml, preferably 0.02 ml liquid.

34. The machine according to any preceding claims 21-33, wherein during step (g) 15-400 ml, preferably 20-250 ml, more preferably 20-120 ml beverage is brewed and / or wherein during step (g) the pump is operated uninterrupted.

35. The machine according to any preceding claims 21-34, wherein the brewing chamber comprises an enclosing member for being loaded with the capsule and a plate for closing the enclosing member, the plate being provided with relief elements for opening the capsule on its outlet side under the influence of fluid pressure in the capsule and the enclosing member being provided with cutting means for opening the capsule at its inlet side.

36. The machine according to any preceding claims 21-35, wherein themachine is provided with a flowmeter for measuring the flowrate of the liquid which is pumped by the pump towards the inlet of the brewing chamber wherein the flowmeter is communicatively connected to the control circuitry for submitting, in use, a signal to the control circuitry representing the measured flowrate, wherein the control circuitry is arranged to control the pump, in use, such that in steps (c)-(g) a predetermined amount of fluid is pumped by the pump towards the inlet of the brewing chamber, and / or such that in step (c) a predetermined amount of fluid is pumped by the pump towards the inlet of the brewing chamber and / or such that in step (g) a predetermined amount of fluid is pumped by the pump towards the inlet of the brewing chamber.

37. The machine according to any preceding claim 21-36 wherein the control circuitry is arranged such that, in use, in each of the carried out steps (d) nl has one and the same value and / or such that in each of the carried out steps (e) n2 has one and the same value.

38. The machine according to any preceding claim 21-37 wherein the control circuitry is arranged such that, in use, in at least two steps (d) of the carried out steps (d) nl has different values respectively and / or such that in at least two steps (e) of the carried out steps (e) n2 has different values respectively.

39. The machine according to any preceding claim 21-38 wherein the control circuitry is arranged such that, in use, in step (c) the pump is operated continuously or such that in step (c) the pump is at least one time interrupted.

40. The machine according to any preceding claims 21-39, wherein the brewing chamber is arranged to selectively being loaded with a capsule of afirst type and a capsule of a second type wherein the capsule of the second type has an outer volume which is larger than an outer volume of the capsule of the first type wherein an inner volume of the capsule of the second type is larger than an inner volume of the capsule of the first type and wherein preferably the capsule of the first type and the capsule of the second type have a similar shape and wherein preferably the capsule of the first type has such a shape that it comprises a largest diameter at its outlet side and wherein preferably the capsule of the second type has such a shape that it comprises a largest diameter at its outlet side wherein preferably said largest diameter of the capsule of the second type is larger than said largest diameter of the capsule of the first type.

41. The machine according to claims 39 and 40, wherein it comprises at least one sensor for generating at least one signal which indicates whether a capsule of the first type or a capsule of the second type is present in the brewing chamber, wherein, in use, the signal is submitted to the control circuitry for controlling in dependence from the signal generated by the sensor the amount of fluid which is pumped during step (c) towards the inlet of the brewing chamber and / or the amount of fluid which is pumped during step (g) towards the inlet of the brewing chamber and / or the amount of fluid which is pumped during steps (c)-(g) towards the inlet of the brewing chamber wherein preferably the at least one signal generated also indicates the presence of a capsule of the first type and the presence of a capsule of the second type in the brewing chamber.

42. System comprising the machine according to any preceding claims 21- 41, loaded with a capsule filled with an ingredient such as ground coffee, the capsule comprising a capsule body sealed with a lid wherein the capsule body comprises a base, a sidewall and a flange wherein the lid is sealed to the flange wherein the base forms the inlet side of the capsule and the lidforms the outlet side of the capsule.

43. System according to claim 42 wherein the system is arranged, in use, to pierce at least one opening in the base for opening the capsule at its inlet side and to tear the lid open under the influence of fluid pressure in the capsule for opening the capsule at its outlet side.

44. System according to claim 43 wherein the enclosing member is arranged, in use, to pierce at least one opening in the base for opening the capsule at its inlet side and wherein the plate is arranged to tear the lid open under the influence of fluid pressure in the capsule.

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