Batch-Brewing Coffee System

Many coffee brewers and systems have been designed to brew coffee in small and large quantities. These systems range from small home-style brewers to large commercial brewers found in restaurants. Likewise, a large variety of coffee is available on the market from raw coffee beans of varying types to freeze-dried and other instant blends.

It is generally accepted that the best, most flavorful and desirable coffee is fresh batch-brewed coffee as is served in coffee houses and restaurants. Single-cup brewers such as found in some vending machines produce a coffee that is considered far less desirable.

There are many fresh batch-brewer systems which include a holding tank in which the brewed coffee is stored, mainly at the proper drinking temperature, and then dispensed on demand. This type of brewer, common in coin-operated machines, is also used in office coffee service and related systems. The quality of coffee from the hot coffee holding reservoir is good right after brewing, but continually decreases overtime until it becomes very strong and unpleasent tasting, which only takes about an hour.

The continual degrading in quality is primarily attributable to the need to keep the brew at an elevated temperature (approximately 170.degree. F.) in order to dispense the coffee at drinking temperature. The temperature is ordinarily maintained by added heaters or by designing a holding tank so that it holds a temperature over the required period because of its insulation. In any event, while the coffee is being held in this reservoir the elevated temperature causes an undesirable cooking of the coffee resulting in the evolution of an unpleasant taste.

Taste tests have shown that if the coffee is cooled after brewing to an ambient temperature, and then stored in the holding reservoir, and not heated until needed, the storage life is significantly increased. The strong, harsh taste is not present even after hours of storage. The only apparent degradation of flavor and aroma takes place only gradually, and even then does not start until more than three hours after the coffee has been brewed.

The present invention provides a means for fresh batch-brewing of coffee, holding the brew within the reservoir where it is cooled, and then heating it cup-by-cup, and only when the coffee is dispensed. This is acheived by a primary holding tank into which the fresh brewed coffee is poured, and a subsequent stage in the dispensing passageway of the coffee in which approximately a one-cup quantity is quickly re-heated, but not boiled, such as by a heat exchanger disposed in a hot water reservoir, with the hot water being used to brew the next batch of coffee.

FIG. 1 is a diagrammatic illustration of the entire brewing system;

FIG. 2 is diagrammatic view of a heat exchange coil which would be found in the cooling tank;

FIG. 3 is a heat exchange system utilizing a hot water jacket around the storage reservoir;

FIG. 4 illustrates yet another embodiment of the coffee cooling reservoir wherein the reservoir is fitted with heat dissipation radiator fins;

FIG. 5 is a somewhat diagrammatic section taken through the hot water reservoir;

FIG. 6 is a section taken along line 6--6 of FIG. 5; and

FIG. 7 is a perspective view of the heat exchanger element used for reheating the coffee.

The invention is described as a coffee brewing system and coffee grounds are mentioned in the specification and claims, because coffee is by far the preferred hot brewed beverage in the United States. However, the system might also be used with tea, chicory, or any other brewed beverage involving the passage of hot water into contact with the flavoradding elements. To the extent that this system is usable to brew other beverages, the term "coffee" and "coffee grounds," used throughout this text for convenience, is hereby defined to include any brewed beverage brewed from any flavoring stock in which the system is useful.

Turning now to the illustrated embodiments, FIG. 1 illustrates the basic operation of the system wherein a hot water reservoir 10 provides hot brewing water for the brewing basket 12 through the head 14. After the coffee is brewed, it flows into the holding and cooling tank 16. A valve 18, operated by the user, causes one cup of coffee to be dropped into the heat exchanger 20, shown in FIG. 5, allowing it to absorb heat from the hot water reservoir 10, as it flows down to the dispensing outlet 21. Although any type of heat exchanger could be used which would ensure against boiling, the heat exchanger 20, better seen in FIG. 7, comprises a flat, hollow, thin chute operated under action of gravity to permit the coffee to contact the hot water in the tank from both above and below.

By utilizing the valve 18, the coffee is not heated until the moment it is demanded, at which time it is dumped into the heat exchanger 20. As an alternative method, a spigot 22 could be used without the valve 18, which would permit approximately one cup's worth of coffee to stand in the heat exchanger 20 until it is drawn off by the user. This would not defeat the purpose of the system, inasmuch as although the cup of coffee would be standing at drinking temperature for a period of time, it would only be the period of time between uses, generally just a few minutes, as opposed to several hours between the time the coffee is first brewed and the time the last cup is drawn off.

Several alternative means of cooling the fresh brewed coffee are shown. FIG. 2 illustrates a heat exchanger 24 which passes fresh, cold water through the pipes on its way to the hot water reservoir 10, inside the holding and cooling tank 16. This same concept could be implemented by the heat exchange system shown in FIG. 3, wherein the incoming water forms a cooling water jacket 24 around the coffee to be cooled. FIG. 4 illustrates a vaned heat radiator 26, which could be used by itself, or in conjunction with either of the systems shown in FIGS. 2 and 3.

Although when using the incoming cold water in a heat exchanger as shown in FIGS. 1 through 3 the water will pick up some heat, it must be heated further, as is accomplished in the illustrated embodiment by the use of the electric heater element 28 extending into the hot water reservoir.

The system as illustrated and described herein provides a whole new technique of brewing and storing coffee, and will be a blessing in restaurants and offices and other environments in which coffee drinkers play Russian roulette with the coffee quality as the day wears on.

While the preferred embodiments of the invention have been described, other modifications may be made thereto and other embodiments may be devised within the spirit of the invention and the scope of the appended claims.