Process and apparatus for preparing a beverage under controlled pressure
A process of preparing a beverage from a beverage preparation chamber includes the steps of feeding water to the preparation chamber ( 2 ) until a first pressure (P 1 ) of at least 3 bar is reached, interrupting the flow of water to the preparation chamber, holding said preparation chamber ( 2 ) in a closed condition for a first time interval (t 1 ), opening said outlet ( 3 ) of the preparation chamber ( 2 ) and delivering the thus prepared beverage whereas the pressure is decreased at least once during said time interval (t 1 ).
1. A process of preparing a beverage, comprising:
feeding water to a closed beverage preparation chamber until a first pressure (P 1 ) of at least 3 bar is reached, wherein the preparation chamber is a closed rigid capsule selected from a closed rigid cartridge and a brewing chamber, the closed rigid capsule avoids deformation of the cartridge while it is pressurized at the first pressure, and the beverage preparation chamber includes an outlet valve:
interrupting at least once a flow of water to said preparation chamber (t pump );
maintaining said preparation chamber in a closed condition at said first pressure (P 1 ) for at least a pressure holding time (t pump −t 1 ) within a range of 1-60 seconds;
opening said outlet valve of the preparation chamber; and
dispensing the prepared beverage from the outlet valve of the preparation chamber.
2. The process according to claim 1 , further comprising:
resuming said flow of water to the said preparation chamber at least once during or at an end of said pressure holding time (t pump −t 1 ).
3. The process according to claim 1 , wherein pressure of the preparation chamber is increased at an end of said pressure holding time (t pump −t 1 ).
4. The process according to claim 1 , wherein pressure of the preparation chamber is decreased at an end of said pressure holding time (t pump −t 1 ).
5. The process according to claim 1 , wherein said pressure (P 1 ) is decreased at least once during said pressure holding time (t pump −t 1 ).
6. The process according to claim 1 , wherein said first pressure (P 1 ) is within the range of 3 to 20 bar.
7. The process according to claim 1 , wherein said first pressure (P 1 ) is within the range of 5 to 17 bar.
8. The process according to claim 1 , wherein said pressure holding time (t pump −t 1 ) is within the range of 5 to 20 seconds.
9. A process for preparing a brewed beverage, comprising:
brewing a beverage in a closed beverage preparation chamber, wherein the preparation chamber is a closed rigid capsule selected from a closed rigid cartridge and a brewing chamber, the preparation chamber includes an outlet valve; and
opening said preparation chamber and dispensing said brewed beverage,
wherein a ratio P open /P disp , for which P open is a pressure at which the beverage preparation chamber is opened and P disp is the pressure at which the brewed beverage is dispensed from said beverage preparation chamber, is set according to characteristics required for a final beverage.
10. The process according to claim 9 , wherein said ratio generally is within a range of 4:1 to 1:4.
11. The process according to claim 9 , further comprising:
interrupting a flow of water to said preparation chamber.
12. A beverage dispensing apparatus, comprising:
a beverage preparation chamber, including an outlet valve;
means for feeding water to the preparation chamber;
means for interrupting at least once a water flow to said preparation chamber once a first pressure (P 1 ) of at least 3 bar is reached and maintaining said first pressure (P 1 ) for a preset pressure holding time (t pump −t 1 );
means for resuming said water flow after said preset time (t pump −t 1 ); and
means for opening said chamber after said preset time (t pump −t 1 ) has lapsed to provide an outlet for the prepared beverage, wherein
the preparation chamber is selected from a closed rigid cartridge and a brewing chamber,
the outlet valve keeps the preparation chamber closed and at a first pressure (P 1 ) for the preset time (t pump −t 1 ) before said preparation chamber is opened, and
the preparation chamber comprises an expansion element for reduction of pressure in the closed preparation chamber during brewing of the beverage.
13. The apparatus according to claim 12 , further comprising:
a controller to operate said interruption, resumption and opening means.
14. The apparatus according to claim 12 , further comprising:
means for detecting pressure within the preparation chamber.
15. The apparatus according to claim 12 , further comprising:
a timer.
16. The apparatus according to claim 12 , wherein said beverage preparation chamber is the closed ridge cartridge and said means for opening is selected from a piercing element and a means of biasing a portion of the cartridge wall.
17. The apparatus according to claim 12 , wherein said beverage preparation chamber comprises at least one piston, a cylinder and a valve.
18. The apparatus according to claim 12 , wherein the preparation chamber is the brewing chamber and the outlet valve is a piezoelectric valve to keep said preparation chamber closed and at the first pressure (P 1 ) for the preset time (t pump −t 1 ) before said chamber is opened.
19. The process according to claim 1 , wherein said pressure holding time (t pump −t 1 ) is within the range of 2 to 40 seconds.
20. The process according to claim 9 , wherein the brewing includes decreasing pressure at least once in the closed beverage preparation chamber.