IE20110230A1 - A method of brewing coffee and a coffee grinding and brewing device employing the method - Google Patents

Abstract

A coffee grinding and brewing device (10) for brewing coffee from roasted coffee beans comprises a grinder (11), a water distribution system (25) for supplying water to the grinder (11) and a brewing chamber (13). In use roasted coffee beans and a volume of water are added to the grinder (11) and the beans are wet ground with the resulting ground coffee/water mixture exiting the grinder (11) directly into the brewing chamber (13). Further water is added and the coffee is allowed to brew for a preset time following which the brewed coffee exits the brewing chamber (13) through a brewed coffee outlet (34). The wet grinding of the coffee beans results in a uniform ground particle size, which improves extraction during brewing. The wet grinding also traps flavours and aromas, which are normally lost where coffee beans are dry ground. This results in a brewed coffee with improved organoleptic properties.

Description

’“iTIT II ____ TRUE COPY AS LODGED ...... nf broking coffee and a coffee grinding and brewing device Ig <1 1 ft 9 g ft employing the method This invention relates to a method of brewing coffee and, in particular, to a method of brewing coffee using freshly ground, roasted coffee beans.

This invention also relates to a coffee grinding and brewing device employing the method and, in particular, to a device, in which coffee beans may be ground and delivered to a brewing chamber to brew the coffee.

It is essential that roasted coffee beans are ground properly, if proper extraction of the beans is to be achieved when brewing coffee. Freshly grinding the beans before brewing coffee is one of the most important steps for achieving a cup of coffee of high quality.

Coffee grind particle size is one of the key factors governing the quantity of soluble solids, which are extracted from the ground coffee during brewing. This quantity of solids extracted, called yield or extraction percentage, directly affects the flavour of the final beverage and ideal ranges for this value have been established within the Specialty Coffee Industry.

Due to the dry, brittle nature of a roasted coffee bean, the grinding process produces a mixture of particle sizes as the beans fracture and fragment. Much effort has been made within the industry to produce OPEN TO PU&UC INSPECTS UfiDER SECTION 28 APW RULE 23 W .....

IE 1 1 0 2 3 0 grinders, which output less variable particle size distributions, resulting in a more uniform yield from all of the ground coffee.

During the grinding process, some of the volatile aromatic compounds contained in the roasted beans are released to the atmosphere, where they are oxidised. Thus, these aromatic compounds are either lost or the oxidised compounds are incorporated into the coffee brew, which impart a stale taste to the brewed coffee.

Thus, space saving coffee making devices have been developed, which combine a grinder with a brewer, so that the coffee beans are ground and delivered to a brewing chamber, where the brewing is immediately initiated.

An example of such a device is the Grind’n Brew, Model GNB1 IH coffee machine manufactured by the Grindmaster-Cecilware Corp., 4003 Collins Lane, Louisville, KY 40245 USA. This machine has a hopper for roasted coffee beans, which are fed to a grinder when required. The ground coffee is delivered by an auger to a brewing chamber and the brewed coffee is delivered through a filter to a coffee jug.

The machine includes a shutter mechanism which keeps water vapour separated from the grinder and auger. This shutter mechanism is included as during the grinding process, as well as ground coffee being produced, a fine powder, primarily bean husk, called chaff fines is also produced. These chaff fines tend to float and separate from the main JE 11 Ο 2 3 Ο stream of ground coffee that emerges from the coffee grinder. During grinding and the associated creation of electrostatic energy, some of the chaff fines adhere to the surfaces of the grinder and other internal components of the machine. Steam, rising from the brewing chamber, mixes with the chaff fines resulting in a gummy substance, which adheres to the machine surfaces. The addition of the shutter mechanism reduces the production of this gummy substance.

However, such shutter mechanisms can often stick, remaining open or closed due to the gummy substance adhering to the mechanism.

US Patent No. 6,988,444, assigned to Grindmaster Corporation, addresses the problem of chaff fines mixing with moistened air from the brewing chamber to form a gummy substance on the auger/grinder mechanisms in a different way. A fan is included for creating a positive pressure air blanket at the interface between the ground coffee delivery system and the brewing chamber so as to minimize movement of moistened air from the brewing chamber into the auger/grinder mechanisms.

A side effect of the operation of the fan is that aromas generated from the grinding and brewing processes are dispersed into the surrounding air, resulting in the production of a powerful olfactory stimulant that greatly assists in the marketing of the brewed coffee to potential customers. However, increased dispersal of such aromas implies that flavours and aromas are not being incorporated into the brewed coffee but are being lost to the atmosphere.

IE 110 2 3 0 US Patent No. 4,226,175 discloses an apparatus for making hot coffee and other beverages, which attempts to save aromas and fragrances originally contained in coffee beans from being lost to the environment. To achieve this, the roasting and grinding of the coffee beans take place inside an enclosed flask in which the coffee is subsequently brewed. The beans are first roasted in a perforated basket suspended in the flask. The beans are then ground using a grinder blade located in the basket. Once ground, hot water is introduced into the grounds to initiate the brewing step. During this stage the blade is operable at low speed to stir the brew, which exits the basket and collects in the flask.

It is an object of the present invention to overcome the disadvantages of the coffee grinding and brewing devices hereinbefore described.

Thus, the invention provides a method of brewing coffee using freshly ground, roasted coffee beans, the method comprising the steps of: a) adding a preferred quantity of roasted coffee beans to a coffee grinder; b) dispensing a volume of water into the grinder, the volume of water being sufficient to form a paste with the coffee beans as they are ground; IE 1 1 Ο 2 3 Ο c) initiating the grinding of the coffee beans in the presence of the water; d) collecting the ground coffee and water paste, as it exits the grinder, in a brewing chamber; e) dispensing a volume of water sufficient to bring the total volume of water in the brew chamber up to a preferred volume for the particular quantity of coffee beans; f) allowing a set time for the coffee to brew; and g) dispensing the brewed coffee into a receptacle.

An advantage of the method in accordance with the invention is that wet grinding the coffee beans reduces bean fracturing during grinding due to the brittleness of the dry beans. This results in ground coffee which has less variability in particle size than the same coffee beans ground in the dry state, resulting in a brewed coffee having improved organoleptic properties.

Another advantage is that volatile aroma molecules, which are lost when the beans are ground dry, are captured in the wet paste during wet grinding.

Another advantage of the method is that the chaff fines are incorporated into the wet paste and will enter the brew chamber with the ground coffee. So the problems associated with chaff fines production are avoided.

Preferably, in the method the following steps are included after step a); IE 1 1 0 2 3 0 a’) dispensing a volume of water into the grinder, the volume of water being sufficient to wet the coffee beans; and b’) allowing a short dwell time for the coffee beans to soften.

The wetting of the coffee beans prior to grinding allows the beans to soften, which further reduces the incidence of bean fracturing during grinding.

In one embodiment of the method the brewed coffee is dispensed through a filter.

Use of a filter will trap any undissolved particles, including the chaff fines in the filter thus providing a more palatable brew and facilitating cleaning of the device.

Preferably, the water temperature in the brewing chamber is in the range of 90 to 98 °C.

This is the temperature range which is known to produce the best quality brewed coffee, as most of the flavour and aroma producing IE11 ο 2 3 0 compounds in the coffee bean will dissolve in water within that temperature range.

In a further aspect of the invention there is provided a coffee grinding and brewing device for brewing coffee from roasted coffee beans, the device comprising a grinder, a water distribution system for supplying water to the grinder, and a brewing chamber, having an inlet directly connected to the grinder and a brewed coffee outlet, such that, in use, the coffee beans are wet ground and the resulting ground coffee/water mixture is introduced into the brewing chamber, together with additional water, as required, to brew the coffee.

An advantage of the coffee and brewing device in accordance with the invention is that the roasted coffee beans are wet ground resulting in coffee grounds having a uniform particle size. This is because the wet grinding reduces the incidence of bean fracturing during the grinding process.

A further advantage of the device is that the organoleptic properties of coffee is improved as flavour and aroma producing compounds, normally lost in a dry grinding process, are trapped in the ground coffee/water mixture.

Another advantage of the device is that any chaff fines produced in the grounding process are also trapped in the ground coffee/water mixture. Thus, fouling of the device with chaff fines is eliminated.

IE 11 Ο 2 3 ο Finally, in contrast to similar prior art grinder and brewer combination devices, there is no requirement for transporting means, such as an auger, to deliver the ground coffee to the brewing chamber. In the device according to the invention the ground coffee/water mix is delivered directly into the brewing chamber.

It will be apparent to the skilled person that once water is added to the coffee beans in the grinder the extraction process will commence. Thus, it is important to deliver the ground coffee/water mixture to the brewing chamber without delay.

Preferably, the grinder is located within the inlet of the brewing chamber.

An advantage of this arrangement is that the ground coffee/water mixture is delivered to the brewing chamber immediately of production thereof. This is important as the brewing process has already begun on addition to the water to the coffee beans, as explained above.

Further, preferably, the water distribution system includes a supply conduit connected directly to the brew chamber.

An advantage of this arrangement is that additional water, at the correct temperature for proper extraction of the coffee grounds, may be added directly to the brewing chamber, as the ground coffee/water mix from the grinder is delivered thereto.

IE 1 1 Ο 2 3 Ο In one embodiment of the device according to the invention, a filtering means is provided for filtering the brewed coffee prior to delivery thereof.

Use of a filter will trap any undissolved particles, including the 5 chaff fines in the filter thus providing a more palatable brew and facilitating cleaning of the device.

Preferably, the filtering means is located in the brewing chamber.

An advantage of this arrangement is that the brewing chamber and filter may be removed for cleaning between brews.

In a further embodiment of the device according to the invention, a hopper for storing coffee beans is located adjacent the grinder.

An advantage of including a hopper is that it speeds up the production of coffee in a commercial setting.

In a further embodiment of the device according to the invention, the water distribution system includes means for rinsing out the grinder and brew chamber between brews.

One of the principal requirements for the production of good quality brewed coffee is cleanliness of the equipment. With the device according to the invention it is a simple task to clean the grinder after use. All that is required is to flush water through it.

IE 1 1 02 30 The grinder can be operated at a slow speed to facilitate the cleaning cycle.

Preferably, an atmospheric boiler is connected to the water distribution system for supplying hot water therefor.

An atmospheric boiler is an efficient source of hot water for both brewing the coffee and for cleaning the device between brews.

The invention will be further illustrated by the following description of an embodiment thereof, given by way of example only with reference to the accompanying drawing, which is a schematic representation of a coffee grinding and brewing device in accordance with the invention.

Referring to the drawing, there is illustrated generally at 10, a coffee grinding and brewing device for brewing coffee from roasted coffee beans in accordance with the invention. The device 10 includes a grinder 11 located within an inlet 12 of a brewing chamber 13. The brewing chamber 13 is cylindrical in shape with a top section 14 and a bottom section 15 connected together by a cylindrical wall 16, part of which has been removed so that the grinder 11 can be seen.

The grinder 11 has a pair of grinding plates 17, 18, connected to a grinder motor 19 by a drive rod 20. The grinder 11 includes an inverted, frusto-conical inlet 21, for receiving coffee beans, in use.

IE 1 1 Ο 2 3 Ο A water distribution system, illustrated generally at 25, includes an atmospheric water boiler 26 having a water delivery tube 27 attached at one end 28 to a side 29 of the atmospheric boiler. The other end 30 of the water delivery tube 27 is located over the inlet 21 of the grinder 11.

A top-up water tube 31 is connected between position 32 on side 29 of the atmospheric water boiler 26 and position 33 on the cylindrical wall 16 of the brewing chamber 13.

A brewed coffee outlet 34 is located in the bottom section 15 of the brewing chamber 13. A filter (not shown) is located within the brewing chamber 13 at the brewed coffee outlet 34.

A hopper 35 for storing coffee beans has a conically shaped storage space 36 with a delivery schute 37 located at the narrow end 38 thereof. The schute 37 directs coffee beans into the inlet 21 ofthe grinder 11, in use. A cover 39 fits on the broad end 40 of the hopper 35.

The operational controls for the device 10 have been omitted from the drawing for clarity. Such controls include coffee dose, water dose and brew time selection, size of grind and brewing water temperature, together with controls for a cleaning cycle.

The method of brewing coffee using freshly ground, roasted coffee beans, in accordance with the invention, will be described with reference to the drawing.

The operator selects the coffee dose, water dose, brew time, size of grind and brewing water temperature. When the brew is initiated the IE 11 ο 2 3 0 operator places a receptacle below the brewed coffee outlet 34. The selected dose of coffee beans is released from the hopper 35 into the inlet of the grinder 11.

A dose of water, which will make up part of the total brew 5 volume, is then dispensed into the inlet 21. A preset dwell time commences allowing the coffee beans to soften in the presence of the water.

A further volume of water is added to the beans, the volume being sufficient to form a paste with the coffee beans as they are ground, and grinding commences.

The beans and water are forced through the grinder plates 17, 18 and exit the grinder 11 as a paste.

The paste drops into the brewing chamber 13 and a further volume of water is added through the top-up water tube 31. The volume of water added at this stage is sufficient to bring the total volume of water up to the water dose set at the start.

After the preset brew time has elapsed the brewed coffee is allowed to drain through the filter and out of the brewed coffee outlet 34 into the receptacle.

Claims (13)

1. Claims: 1. A method of brewing coffee using freshly ground, roasted coffee beans, the method comprising the steps of: a) adding a preferred quantity of roasted coffee beans to a 5 coffee grinder; b) dispensing a volume of water into the grinder, the volume of water being sufficient to form a paste with the coffee beans as they are ground; c) initiating the grinding of the coffee beans in the 10 presence of the water; d) collecting the ground coffee and water paste, as it exits the grinder, in a brewing chamber; e) dispensing a volume of water sufficient to bring the total volume of water in the brew chamber up to a preferred 15 volume for the particular quantity of coffee beans; f) allowing a set time for the coffee to brew; and g) dispensing the brewed coffee into a receptacle.

2. A method according to Claim 1, wherein the following steps are included after step a); IE 1 1 0 2 3 0 a’) dispensing a volume of water into the grinder, the volume of water being sufficient to wet the coffee beans; and b') allowing a short dwell time for the coffee beans to 5 soften.

3. A method according to Claim 1 or 2, wherein the brewed coffee is dispensed through a filter.

4. A method according to any preceding claim, wherein the water temperature in the brewing chamber is in the range of 90 to 98 °C. 10

5. A coffee grinding and brewing device for brewing coffee from roasted coffee beans, the device comprising a grinder, a water distribution system for supplying water to the grinder, and a brewing chamber, having an inlet directly connected to the grinder and a brewed coffee outlet, such that, in use, the coffee beans are wet ground and the 15 resulting ground coffee/water mixture is introduced into the brewing chamber, together with additional water, as required, to brew the coffee.

6. A coffee grinding and brewing device according to Claim 5, wherein the grinder is located within the inlet ofthe brewing chamber.

7. A coffee grinding and brewing device according to Claim 5 20 or 6, wherein the water distribution system includes a supply conduit connected directly to the brew chamber. IE 1 1 ο 2 3 Ο

8. A coffee grinding and brewing device according to any one of Claims 5 to 7, wherein a filtering means is provided for filtering the brewed coffee prior to delivery thereof.

9. A coffee grinding and brewing device according to Claim 8, 5 wherein the filtering means is located in the brewing chamber.

10. A coffee grinding and brewing device according to any one of Claims 5 to 9, wherein a hopper for storing coffee beans is located adjacent the grinder.

11. A coffee grinding and brewing device according to any one 10 of Claims 5 to 10, wherein the water distribution system includes means for rinsing out the grinder and brew chamber between brews.

12. A coffee grinding and brewing device according to any one of Claims 5 to 11, wherein an atmospheric boiler is connected to the water distribution system for supplying hot water therefor.

13. 15 13. A coffee grinding and brewing device according to Claim 5 for brewing coffee from roasted coffee beans, substantially as hereinbefore described with particular reference to and as illustrated in the accompanying drawing.