Technical Field of the Invention

The present invention generally relates to apparatus and methods for producing brewed drinks, in particular from roast and ground coffee beans and other related products reguiring soluble solids extraction into water.

Background

Brewed beverages such as coffee, chocolate and tea have been very popular around the world for thousands of years. These drinks are usually brewed quickly in hot (boiling) water and much more slowly in ambient or cold water.

Experts agree that cold brewed beverages display significant benefits of taste, appearance, mouth feel, nutrition as well as significantly improved pharmacological and physiological effects over hot brewed beverages.

T raditionally , cold brew coffee is made by immersing ground roasted coffee beans in water at room temperature over 18 to 24 hours. This process is time consuming and is subject to variations in extraction as well as low extraction rates, all of which make it expensive for manufacturers of these beverages.

Further, the carbon dioxide gas formed during the roasting process, and retained within the ground coffee beans, can cause the brewing water to become acidified, which adversely affects the brewed beverages and impedes hydration of the solids. The long brew time in the presence of air can also cause unwanted oxidation of the beverage. ln attempts to reduce the brewing time and improve the extraction yield, a variety of systems have been developed over the past 40 years, the most noteworthy of which comprises applications of vacuum before and during the brewing stage.

JPH0678678A describes an apparatus that uses vacuum to accelerate the extraction of coffee in water and US 2020/0170440 A1 discloses pulsing the vacuum on and off. Systems described in these patent documents and other more recent systems have enabled the cold brewing time to be reduced to less than an hour as well as improving the % extraction rate, but they have not addressed the problem of acidification of the brewing water.

Further, these prior art apparatuses have other drawbacks, including large volumes to evacuate in industrial applications as the brewing vessel starts off empty, loss of fine solids and the more volatile flavours if vacuum is applied to the solids before water addition, or from the surface of the water from unhydrated solids if the water is added first or in stages, and during the de-bagging operation.

These drawbacks adversely affect the yield and flavour of the finished beverage and increase the time and energy required to create the required vacuum within the brewing vessel.

Summary of the Invention

Aspects of the present invention aim to eliminate the above mentioned problems during the accelerated vacuum extraction of beverages based on roast ground coffee and other bean or leaf solids as well as simplify the transport and hydration of the coffee grounds in large scale industrial vacuum brewing systems.

According to the invention, there is provided an apparatus for brewing beverages comprising a first vessel part fixed in the apparatus and a second removeable from the apparatus, and connectable with the first vessel part to form a brewing vessel in use, a sealing means between said vessels a first inlet port configured to provide liquid into said first vessel part; a first exit port configured to transport gas out of said first vessel part connectable to a vacuum means; a second inlet port configured to provide solid material and gas into said first vessel part; a second exit port configured to transport liquid out of said second vessel part; a hopper configured to collect solid material; a conduit configured to connect said hopper with said first vessel part of said two part vessel.

Preferably, the first vessel part comprises an agitating means which acts to rotate the water and aid mixing.

Preferably, the second vessel part comprises a removeable filter allowing the filter to be changed when required.

Preferably, the first and second parts are vertically alignable to facilitate the collection of waste ground solids after extraction has taken place, the second vessel part beneath the first vessel part, in use, the apparatus further comprising means for raising the second vessel part towards the first vessel part to releasably connect said parts forming the brewing vessel. A sealing mechanism such as a gasket or sealing ring to provide a hermetic seal between said first and second vessels

Optionally, said conduit comprises a non-return valve.

Optionally, said conduit comprises a control valve to allow the fluid flow rate to be controlled.

Preferably, said conduit comprises a curved section such as a ‘swan neck’ to provide a continuously open top section of conduit above the upper level of liquid in the first vessel to allow solids to enter the apparatus without allowing liquid to exit via said conduit.

Preferably, the apparatus further comprises lifting means operable to raise or lower the removeable filter and facilitating access to the filter.

Preferably, the removeable filter is a filter basket and includes doors allowing the waste coffee grounds to be emptied without the need to rotate the basket. Optionally, the removeable filter is a filter basket and includes a rotating means to allow emptying of waste coffee grounds without the need for doors.

Optionally, the lifting means comprise a gantry and a hoist enable the basket to be traversed laterally.

Optionally, said gantry is configured to allow rotation of said filter basket.

Preferably, the apparatus further comprises a means of heating a liquid within said formed brewing vessel.

Preferably, the apparatus further comprises a controller for automatically controlling the pressure and temperature within said formed brewing vessel.

Preferably, the apparatus further comprises a means of transferring liquid from the second vessel part to the first vessel part.

Preferably, the apparatus further comprises a means of applying positive pressure within the first vessel part.

Brief Description of the Drawings

The invention is described with respect to the accompanying Figures which show by way of example only, an embodiment of an apparatus for brewing beverages. In the drawings:

Figure 1 illustrates one embodiment of an apparatus for brewing beverages;

Figure 2 is a sectional view of the apparatus showing a discharge from the hopper, the swan neck conduit, and the tangential solids entry into the upper brewing vessel;

Figure 3 is another sectional view of the apparatus showing a vertical paddle mixer located within the upper brewing vessel and the filter located within the lower brewing vessel;

Figure 4 shows the first stage of operation of this embodiment of the apparatus;

Figure 5 shows the second stage of operation of this embodiment of the apparatus; Figure 6 shows the third stage of operation of this embodiment of the apparatus of;

Figure 7 shows the fourth stage of operation of this embodiment of the apparatus;

Figure 8 shows the fifth stage of operation of this embodiment of the apparatus;

Figure 9 shows the sixth stage of operation of this embodiment of the apparatus;

Figure 10 shows the seventh stage of operation of this embodiment of the apparatus;

Figure 11 shows the final stage of operation of this embodiment of the apparatus;

Figure 12 shows a further embodiment of apparatus; and

Figure 13 is a further view of the embodiment of Figure 12.

Detailed Description of the Invention

Figure 1 shows an example apparatus X for producing brewed coffee, where a is a hopper comprising a sieve above a bottom outlet. The apparatus X comprises a vertically aligned two-part vessel having a fixed upper part f and a removeable lower part s. A conduit c with a curved section known as a swan neck z, a non-return valve d and a control valve e is connected to the upper brewing vessel f incorporating vacuum/water port g, spray ball connection h and vertical paddle mixer I functioning as agitating means.

The lower mobile brewing vessel s, which can be raised and lowered by lever arm b. The lower mobile brewing vessel s further comprises screw clamps n, flexible seal r and a discharge conduit t. Filter p within basket m is removable using a spreader bar I and a chain hoist k suspended from a gantry j to enable the basket m to be traversed laterally to a location q located on spigot u where the basket m can be rotated through 360 degrees about the sleeve or pivot arm o.

Figure 2 is a sectional view of the apparatus shown in Figure 1 , illustrating the discharge from the hopper a, the conduit c, and the tangential solids entry into the upper brewing vessel f.

Figure 3 is another sectional view of the apparatus shown in Figure 1 , illustrating the vertical paddle mixer i located within the upper brewing vessel f and the filter p located within the lower brewing vessel s.

Figures 4 to 11 show, in sequence, operating stages of the apparatus x. Figure 4 shows the apparatus at the start of a production cycle with the filter basket m suspended from the overhead gantry j ready to be lowered into the lower brewing vessel s. Figure 5 shows the filter basket m in place within the lower brewing vessel s ready to be pushed under the upper brewing vessel f with the seal control lever arm b in the unsealed position.

Figure 6 shows the lower brewing vessel s in place under the upper brewing vessel f ready for the sealing control lever arm b to be rotated downward as shown in Figure 7, which acts on the lower brewing vessel supports (not shown) to raise said lower brewing vessel s into direct contact with the upper brewing vessel f flange.

As soon as the lower brewing vessel s is in the raised position, all the screw clamps n are tightened compressing the seal r and thereby creating an airtight seal between upper and lower brewing vessels f, s and the discharge conduit t is connected to a discharge valve (not shown). The discharge valve is closed ready for the start of brewing.

The required quantity of water is then injected into the upper brewing vessel f through the connecting port g. The vertical paddle mixer i is activated which, in this example, rotates the water in a counter-clockwise direction when viewed above, and the pressure in the vessel is reduced to create air movement from the hopper a through the conduit c. The non-return valve d stops water from entering the conduit c.

Advantageously, the amount of air to be removed from the brewing vessel to create a vacuum is minimal as most of the vessel’s volume is taken up with the water, unlike the prior art apparatuses.

Coffee grounds are transferred from previously sealed bags directly into the hopper a through a sieve. The airflow towards the brewing vessel is insufficient to cause the coffee grounds to be transferred but is sufficient to stop the finest particles of coffee as well as the volatile flavourings from escaping into the atmosphere - instead they are retained within the coffee in the hopper a or drawn into the brewing vessel through the conduit c. Once all the required coffee grounds have been transferred into the hopper a the rate of evacuation of the brewing vessel is increased which starts to draw the coffee from said hopper a into the upper brewing vessel f via the tangential entry point of the conduit c into the brewing vessel as shown in Figure 2.

This tangential entry assists the rotation of the water mass and maximises the time that the coffee grounds are in contact with the water held within the brewing vessel f before the combination of air from the brew room and carbon dioxide from the coffee grounds reaches the top surface of the water and both gases are evacuated through the vacuum pump.

Advantageously, the task of transporting the coffee grounds into the water mass and the subsequent hydration of the coffee grounds, fine and dissolving of coffee volatiles is greatly simplified compared to the prior art, and the production yields and coffee flavours are also much improved. Additionally, there is no need to prefilter the vacuum pump as all the fine solids are retained within the water mass. Finally, the mixing of air with the carbon dioxide naturally stored within the roast coffee granules and the very short contact time for both oxygen and carbon dioxide with the water the acidification problems with the water and oxidation of the coffee are minimised.

As soon as all the coffee grounds have been transferred, the control valve e is closed, the vacuum pressure inside the upper brewing vessel f is increased to the required set point and is thereafter controlled by a programable logic controller.

The minimum vacuum pressure is kept above 20 mmHg to eliminate boiling of the water at ambient temperature and thereby eliminate the need to heat the water to retain ambient water temperature during brewing due to the evaporation of water vapour at lower pressures.

Once the required extraction has taken place the coffee concentrate is drained via the discharge conduit t with all the waste coffee grounds being retained as a bed on top of the filter in the bottom brewing vessel s. The rate of drainage can be controlled using over pressurization of the brew vessel using hygienic compressed air through the connector port g. Typically, an overpressure of from 0.2 - 2.0 bar is applied. If required, a stage of pre-fi Itration can be carried out by pumping a small quantity of coffee concentrate from the discharge conduit t back into the upper part of the vessel to entrap all of the very fine particles of coffee that bypassed the filter prior to the formation of a bed of extracted coffee grounds within the filter basket m.

With reference to Figure 8, as soon as all the coffee concentrate has been drained the discharge valve is closed and the extract conduit c is disconnected. The screw clamps n are undone and the lower brewing vessel s is lowered to the floor by raising the lever b such that said lower brewing vessel s can be moved under the gantry j to enable the filter basket and waste coffee grounds can be lifted out of said lower brewing vessel s using the hoist k and spreader bar I (as shown in Figure 9).

With reference to Figure 10, as soon as the filter basket m is clear of the lower vessel s, the lower vessel s is moved back under the upper vessel f and the filter basket m is lowered to allow the rotational spigot u and sleeve o to be aligned after it is moved laterally along the gantry beam j.

With reference to Figure 11 , the spreader bar I is then disengaged from the filter basket m and moved out of position to allow a waste container to be placed under said filter basket m, which can then be rotated 180 degrees about the axis of the spigot u allowing the waste coffee to be easily removed from the filter p, which in turn can be cleaned by water spray from the underside.

Once cleaned the filter basket m is returned to the lower brewing vessel s by reversing the above actions and the lower brewing vessel s is then placed in position under the upper brewing vessel f ready to repeat the production cycle.

Advantageously, the task of emptying the waste coffee and cleaning the filter are greatly facilitated compared to the prior art.

Figures 12 and 13 show an alternative embodiment of the Brewing Apparatus Y wherein the lifting pulley k is directly mounted on the upper brewing vessel f and the brewing basket m has two hinged bottom doors w unlocked by clamps v allowing the waste coffee grounds to be emptied without the need to rotate the basket m as shown in the Brewing Apparatus X.

Although the above detailed descriptions refer to preferred embodiments of the invention and coffee as the beverage, it will be appreciated that aspects of the invention have alternative applications, and can be used for a whole range of brewed beverages.