COLD BREW COFFEE MAKING APPARATUS AND METHOD

Abstract

A coffee brewing apparatus and method that produces coffee using an agitation and cold brew operation. A high temperature strike stage with agitation is followed by a cold brew stage, with a displacement pump configured to transfer the coffee oils and extracts, shortening the time necessary to achieve a brew cycle. The brewing cycle of the present invention preferably uses a six stage sequence that includes introduction of strike water, agitation, bloom, brew water introduction, extraction, and dilution. The various stages are performed using a brewing system that includes an agitation system, a displacement pump, and a filtering system used to extract the oils and extracts of the coffee for brewing.

Claims

1. A beverage brewing system comprising: a non-pressurized, removable brew chamber; an agitation motor; a removable agitation paddle rotated by the agitation motor and disposed in the brew chamber; a pump configured to communicate a negative pressure to the brew chamber; a water delivery system configured to deliver both non-ambient strike water and ambient diluting water to the brew chamber; and a processor for controlling the agitation paddle and the pump.

2. The beverage brewing system of claim 1, wherein the brew chamber is open to atmospheric pressure.

3. The beverage brewing system of claim 2, wherein the brew chamber includes a porous filter disposed between the agitation paddle and a brew chamber base.

4. The beverage brewing system of claim 3, wherein the brew chamber is mounted onto the base and the pump connects with the brewing chamber through the base.

5. The beverage brewing system of claim 1, wherein the brew chamber includes a cover that rotates from a closed position to hold the paddle in place and prevent splashing, and an open position to allow removal of the agitation paddle.

6. The beverage brewing system of claim 1, wherein a beverage is evacuated from the brew chamber using the pump.

7. A cold brew beverage brewing apparatus, comprising: a housing; a brewing chamber; a base supporting the brewing chamber; an agitation system including a motor and paddle that rotates within the brewing chamber; a pump in fluid connection with the base for causing a negative pressure condition in the brew chamber; and a controller for controlling a brewing operation including initiating a wetting step, an agitation step, and an extraction step within the brew chamber.

8. The cold brew beverage brewing apparatus of claim 7, wherein the brew chamber is open to the atmosphere at some period during the brewing operation.

9. The cold brew beverage brewing apparatus of claim 7, wherein the brew chamber is clamped to a platform via a lever.

10. The cold brew beverage brewing apparatus of claim 7, wherein the controller controls a speed of the agitation paddle.

11. The cold brew beverage brewing apparatus of claim 10, wherein the agitation paddle is removable from the brewing apparatus.

12. A method for brewing coffee using a coffee brewing apparatus, the method comprising: providing a brew chamber with coffee grounds; introducing hot (strike) water to the grounds; agitating a slurry of grounds and hot water using an agitation system; introducing ambient water into the brewing chamber; introducing negative pressure into the brew chamber to accelerate the transfer of concentrated coffee extracts from the grounds; and diluting a resulting concentrate with additional water after the introducing the negative pressure in the brew chamber.

13. The method for brewing coffee of claim 13, further comprising the coffee brewing apparatus accessing recipes from a remote location.

14. The method for brewing coffee of claim 12, wherein the pump is located within the coffee brewing apparatus.

15. A beverage brewing system comprising: a non-pressurized, removable brew chamber; an agitation motor; a removable agitation paddle rotated by the agitation motor and disposed in the brew chamber and magnetically coupled to a shaft of the agitation motor; a pump; a beverage receptacle fluidly connected between the pump and the brew chamber and configured to communicate a negative pressure from the pump to the brew chamber; a water delivery system configured to deliver both non-ambient strike water and ambient diluting water to the brew chamber; and a processor for controlling the agitation paddle and the pump.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a perspective view, partially in shadow, of a first embodiment of the present invention;

[0010] FIG. 2 is an enlarged, perspective view of a brew chamber and clamping mechanism of FIG. 1;

[0011] FIG. 3 is an exploded view of the brew compartment of the embodiment of FIG. 1;

[0012] FIG. 4 is an exploded view of an alternate brew compartment;

[0013] FIG. 5 is an elevated, perspective view of an agitation paddle of the embodiment of FIG. 1;

[0014] FIG. 6 is an elevated, perspective view partially in shadow of a second embodiment of the present invention;

[0015] FIG. 7 is an exploded view of a brew chamber and pump coupling;

[0016] FIG. 8A is an exploded side view, partially in shadow, of the pump coupling;

[0017] FIG. 8B is a side view, partially in shadow, of the pump coupling of FIG. 7;

[0018] FIG. 9A is a graph showing a brewing sequence for the present invention;

[0019] FIG. 9B is a graph showing a second brewing sequence for the present invention;

[0020] FIG. 10 is an elevated, perspective view, partially in shadow, of the agitation system of the present invention;

[0021] FIG. 11 is an elevated, perspective view of the agitation system;

[0022] FIG. 12 is an exploded view of the agitation system; and

[0023] FIG. 13 is a schematic view of the beverage reservoir and pump/brew chamber arrangement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] FIG. 1 illustrates the components of a cold brew coffee brewing apparatus 10 embodying the features of the present invention. The apparatus 10 includes a sturdy housing 12 that holds and encloses the components of the brewing apparatus. A control pad 14, which may be a touch screen or other key pad device, allows a user to enter information to be used in a brewing operation, such as brew volume quantity, brew time, agitation time, extraction (pump) time, preferences (strong, weak, etc.), as well as provide information such as a timer from indicating completion of the brewing operation. On the front of the housing 12 is a lever 16 that is connected to a linkage 18 that clamps a brew chamber 20 to a chamber base 22. The brew chamber 20 is cylindrical and has a mounting block 40 on an exterior surface that engages with the linkage 18 to clamp the brew chamber 20 in place (see FIG. 2). A base 22 is mounted to first and second rails 24 so as to position the brew chamber 20 in proximity with an agitation paddle 26 (see FIG. 5). The agitation paddle 26 is seated within the brew chamber 20 and comprises first and second panels 28 that help stir the grounds for better wetting and extraction. The agitation paddle 26 includes a neck 30 having an upwardly projecting tab 32 that is received by a coupling 34 using a locking nut 36. The coupling 34 depends from a faceplate 42 which is part of the agitation motor assembly 44, which includes a motor 46 to turn the agitation paddle 26. The agitation motor assembly 44 is controlled by a processor (not shown) that may be part of the control pad 14 and sends signals to the motor assembly 44 to initiate, control, and terminate an agitation step.

[0025] FIG. 1 also illustrates a water delivery system that includes a valve 48 for filling the hot water tank 50 mounted on a shelf 51, a valve 52 that introduces ambient water to mix with the hot water, and a valve 54 used to dilute the concentrated coffee after ground extraction. Connections between the hot water tank 50 and the brew chamber 20 are omitted for clarity.

[0026] The apparatus is also equipped with a pump 56 for generating a negative pressure in the conduit that is connected to the bottom of the brew chamber 20. The pump 56 is controlled by the processor in the control pad 14, which activates and deactivates the pump 56 as part of the extraction process.

[0027] FIG. 2 is an enlarged view of the brew chamber 20. The brew chamber 20 has two elongate slots 60 that can be used to grip the brew chamber 20, and a support bracket 62 that positions the brew chamber 20 on the chamber base 22. A clamp 64 secures the brew chamber 20 to the chamber base 22 as the lever 16 is pivoted, and releases the brew chamber 20 from the chamber base 22 when the lever 16 is pivoted in the opposite direction.

[0028] FIG. 3 illustrates an exploded view of the components of the assembly 66 that fits inside the brew chamber 20. The brew assembly 66 comprises a cylindrical brew sleeve 68, a silicon or plastic base 70, a paper filter 72, a perforated metal or plastic filter 74, and a locking cap 76 having a central aperture 78. The assembly fits into the brew chamber 20 and seals the chamber to form an air tight compartment. FIG. 4 illustrates an alternative assembly comprising a brew chamber 80, a brew basket 82, a perforated plate 84, a filter 86, and cross plate 88. It can be seen that the brew chamber 80 includes a slot 90 that receives a lug 92 on the brew basket 82 to capture the basket in the chamber.

[0029] The control pad 14 may include electronics that allow the processor to be accessed by a phone or tablet in order to control the apparatus, using either a Bluetooth connection or some other wireless connection. This can be accomplished through an application downloaded onto the phone or tablet, or other graphic interface on the phone. The phone, or the device itself, can access a remote server to recall recipes, software updates, tips, and other user information.

[0030] A preferred brew sequence is now be described in detail. The first stage is a strike phase, where the brew cycle begins with the introduction of water via valve 48. The water wets the grounds in the brew chamber, initiating the extraction of the oils and extracts of the ground coffee beans. During the strike step of the brew cycle, a target strike water temperature is 201 F.+/4 degrees, as this temperature has been found to effectively target soluble acid and sugar in coffee grinds while avoiding adversely scalding of grinds. The target quantity of water is 96 ounces to 112 ounces, depending on coffee amount driven by recipe.

[0031] A few seconds after the strike water is introduced, the agitation motor is activated to initiate the agitation phase of the process. During the agitation phase, strike (hot) water is continually added from the hot water tank 50 to the brew chamber 20. During the agitation phase, the agitation paddle 26 stirs the coffee/water slurry for one to two minutes. The motor assembly 44 rotates the paddle 26, for example, at about 140 to 170 revolutions per minute, thereby fully wetting the grounds and preparing the grounds for extraction.

[0032] After the agitation phase, a thirty (30) second delay is initiated where the grounds settle and the strike water permeates the grounds. After the pause, the beginning of brew cycle phase is initiated by the introduction of ambient temperature brew water into the mixture. An exemplary target temperature is 50-80 degrees F., and coffee extraction efficiency is mostly unaffected within this ambient temperature range. An optional hot brew water phase can be used in place of the ambient brew water phase. The ambient water valve 52 remains open for one to two minutes to fill the brew chamber 20, where a typical target brew water volume is two gallons. The controller begins and ends all of the operations, and the timing can be adjusted to the tastes of the user. The introduction of the ambient water in the brew cycle phase results in a short bloom phase wherein the coffee bed settles and levels in preparation for the subsequent extraction.

[0033] Concurrently, at the initiation of the bloom phase, pump 56 (see FIG. 13) transfers liquid from the brew chamber 20, passing through a strainer 112, in the direction of conduit 93 to the open container 99. Cold or ambient water is delivered to the apparatus 10 by cold water supply 107, which is routed into either the hot water heater 50, the brew chamber 20, or via conduit 111 to the open container 99 as needed. The open container 99 is attached to a tee fitting 110. This transfer phase may take between 8 minutes to 15 minutes, depending on recipe. The range in time is driven by grind size, strike volume, and brew water volume as dictated by programmed recipe or user customized recipe.

[0034] Once the transfer process is completed, bypass water from valve 54 may be introduced directly to the open container 99 to dilute the concentrated beverage. The duration of the bypass water introduction phase is dependent on bypass water flow rate through the valve 54, where a typical volume would be on the order of two to two and one half gallons per minute. This allows the concentrated coffee from the extraction process to be diluted to yield the proper ratio of concentrate to bypass water in the beverage.

[0035] In some embodiments, a two phase brew water cycle can be employed for better mixing and cooling of the beverage. Parameters that are controllable using the apparatus of the present invention includes coffee amount (approximately 3.0 pounds to 4.0 pounds driven by recipe), flavor profiles adjusted by manipulating the extraction rates of targeted acid, sugar, and dry distillation flavors inherent in coffee grinds, and grind size (fine to medium fine, for example).

[0036] FIG. 6 illustrates a second embodiment of the present invention, where like elements repeat like reference numbers. Housing 12 encloses a brew chamber 200, pump 56, base 22, and agitation assembly. As seen in FIG. 7, the brew chamber 200 couples to its base 220 and a stem 210 in the base 220 locks into a pump's port fitting 230 (FIG. 8A,B) to communicate the negative pressure to the brew chamber. The brew chamber receives the stem like a socket and provides a fluid path from the pump to an external container, and then to the brew chamber through the base 220. In a preferred embodiment, the brew chamber 200 is slid horizontally into the base 220, causing the stem 210 to engage the fitting 230 and opening the transfer path through the stem (connected to the pump 56 in series with a keg or bag-in-box via hose) to inside the brew chamber 200. This allows the brewed beverage to be drawn from the brew chamber through the filters and interceding elements into the keg or bag-in-box to significantly reduce the overall brew time.

[0037] FIGS. 10 and 11 show the agitation system, where motor 44 turns axle 46 that rotates paddle 226. This paddle stirs the grounds and ensures adequate wetting during the various phases of the brew cycles. In a preferred embodiment, the paddle 226 is connected to the axle by a magnetic coupling 280 for easy removal and cleaning. The base 274 of the brew chamber 200 includes apertures that allow the negative pressure from the stem 210 to reach the brew area where the grounds are stirred. A cover plate 240 can be rotated using a finger slot 255 so that the wedge shaped opening 250 is closed during the agitation phase to prevent splashing, and then rotated back so that the brew chamber 200 can be easily removed from the base 220. FIG. 12 shows an exploded view of the agitation system, with motor shaft 46 connected to the paddle 226 via magnetic coupling of the paddle 281, and the cover 240 enclosing the brew chamber 200 that is seated in the base 220.

[0038] FIGS. 9A and 9B illustrate two brew operations that can be conducted with the present invention. Using the timeline on the upper bar, a twelve minute process is depicted in FIG. 9A. The strike water phase 310 occurs in two periods from zero to thirty seconds. The agitation phase 320 begins shortly after the first strike water phase is initiated and lasts for just over a minute. The agitation phase 320 is followed by a brief thirty second bloom phase 330, followed by a one to two minute brewing phase 340. The brewing phase is shortly after the brew phase 340 begins, extraction 350 begins and lasts for approximately eight minutes. Finally, after extraction 350 the dilution phase 360 begins where water is added to the concentrate to make the drinkable beverage. In FIG. 9B, the brewing phase 340A has a secondary brew water phase after a delay.

[0039] While several embodiments have been disclosed in the foregoing description and in the drawings, the invention is not limited to any described or depicted embodiment. A person of ordinary skill in the art would readily recognize and appreciate many modifications and substitutions to the embodiments described, and the present invention is intended to include all such modifications and substitutions.