IMPROVEMENTS IN AND RELATING TO A BEER CONTAINER

Abstract: A dispenser for beer or the like comprising a container filled with a beverage having carbon dioxide in solution to between about 5/8 to 3/4 of its volume, the head space above the beverage being filled with a gas under pressure. When liquid is dispensed from the container the loss of CO₂ dissolved in the liquid is less than that in dispensers known hitherto because the pressure in the head space remains relatively high and consequently less CO₂ comes out of solution with the liquid. Hence a dispenser having a substantial head space significantly increases the ability to dispense relatively large volumes without requiring any significant restoration time.

Description: This invention relates to the dispensing of carbonated beverages and in particular, beer. It is desirable to provide a carbonated beverage dispensing apparatus which may for example be kept in the home and used to dispense only a part of the volume of the container at any one time whilst retaining the remainder in good condition and under sufficient pressure to facilitate further dispensing. If, as in a conventional soda syphon, a carbonated beverage occupies virtually all of the volume of the container and a significant amount of the beverage is dispensed, then the volume of the head space is increased, the gas pressure drops and dispensing ceases. Further dispensing may be possible after a lapse of time as carbon-dioxide dissolved in the beverage comes out of solution due to the drop in pressure, restoring pressure in the head space. This, however, means that the quality of the remaining beverage suffers and with the substantial amounts drawn off at any one time for example in the case of beer or lager, the time delay could be unacceptable. It is a general object of this invention to try to overcome this problem. German patent Application No. 1432460 describes a method of storing and dispensing a perishable liquid in which a cask is partially filled with liquid and nitrogen gas is introduced into the head space above the liquid to expel air from the cask. This prevents the liquid from oxygenation and allows heating of the liquid, in the cask, to pasteurise it without impairing the taste. One example describes that 40 litres of beer can be held in a 60 litre cask with nitrogen at a pressure of 2.5 atmospheres in the head space. US Patent No. 3063481 describes a method of dispensing a beverage, which beverage is to be provided with dissolved carbon dioxide and nitrogen. The method includes employing either nitrogen gas alone or a mixture of nitrogen and carbon dioxide gas to expel the beverage from a dispenser. The gas is introduced into the dispenser during dispensing from a supply thereof. Thus a separate gas supply has to be provided as well as suitable valving to control the flow of the gas into the portion of the dispenser containing the beverage. A beverage dispenser for use in the invention comprises a container which may, for example, be of plastic material which is a good gas barrier such as polyethylene terephthlate (PET) made, for example, by injection blow moulding in one piece or by injection moulding in two pieces which are subsequently attached together. The container, which is provided with a dispensing valve or tap, is known per se. Such a dispenser in accordance with the invention is prepared for dispensing carbonated beverages by filling the container with a carbonated beverage and dispensing the beverage from the container by operating a tap which controls flow of the beverage through an aperture in the container, characterised in that the container is filled to between 5/8 to 3/4 of its volume, in that the preparation of the dispenser for dispensing includes filling the head space above the beverage with gas under pressure comprising nitrogen at a pressure of 14 psi (95 x 10³ N/m²) above atmospheric and in that the dispensing of the beverage from the container is carried out without filling any further gas into the head space. It has been found that such a dispenser having a substantial head space significantly increases the ability to dispense relatively large volumes without requiring a restoration time. It also reduces the vulnerability to temperature change since if the temperature rises and gas comes out of solution from the beverage, the relative pressure increase is much less than would be the case if the container was full. Furthermore with such an arrangement, as liquid is dispensed the loss of CO₂ dissolved in the liquid is much less because the pressure in the head space remains relatively high, as compared with the case of a conventional dispenser after a similar amount of beverage has been dispensed, and consequently less CO₂ comes out of solution from the beverage. If the temperature drops then a relatively small amount of N₂ is dissolved as this gas is less soluble than CO₂. The use of N₂ helps to maintain the pressure in the head space when beer or other carbonated beverage is dispensed as relatively little is dissolved in the beverage being dispensed. The Nitrogen "softens" the beer, but this can be compensated by increasing the amount of CO₂. ("Softening" is a reduction in the CO tingle on the tongue). As an example, of the invention, 5 litres of beer containing the maximum CO₂ required, is introduced into a 7 litre container at atmospheric pressure. Nitrogen is then charged into the head space of about 2 litres, at 14 psi above atmospheric (at 95 x 10³ N/m² above atmospheric) so that 4 litres of nitrogen occupy the 2 litres of head space. With such an arrangement it has been found that with normal temperatures and atmospheric pressure the beer is under pressure at all stages during dispensing so that air is not sucked into the container as beer is dispensed. In theory when the head space has been increased to 4 litres in volume due to dispensing of two litres of beer, the partial pressure of the nitrogen is atmosphere (4 litres of Nitrogen being originally charged into 2 litres of head space volume). However, some CO₂ will have come out of solution in the beer until an equilibrium is reached between the partial pressure of CO₂ gas in the head space and that of the CO₂ in solution. By initially providing the beverage with the appropriate amount of CO₂, it can be ensured that the CO₂ content of the beer, when this equilibrium is reached, will be acceptable. Furthermore, at the stage when 2 litres of beer has been dispensed, the head space pressure will still be above atmospheric due to the presence of CO₂ gas therein. When the dispenser is used to dispense lager it is believed to be desirable to have a pressure of 8 psi (55 x 10³ N/m²) in the head space as the last pint is dispensed. The container may have a screw neck at one end and a matching cap with two apertures, each carrying an appropriate fitment. One aperture may be for the purpose of filling the container and is advantageously on the central axis of the container so that no orientation of the container is needed for filling. This could be sealed by a non-removable plug or cap, or by a screw cap or screw bung. The second aperture may carry a dispensing tap capable of dealing with the pressures involved. It is anticipated that a cradle would be provided so that the container would be used in the conventional barrel position with its major axis horizontal. The tap would preferably be positioned adjacent the perimeter of the end face so that when the container is supported as described above the tap can be positioned as low as possible relative to the major axis of the container to allow the maximum amount of beverage to be dispensed before tipping becomes necessary.

Claims: A method of dispensing carbonated beverages from a dispenser, the dispenser including a container, comprising preparing the dispenser for dispensing carbonated beverages by filling the container with a carbonated beverage and dispensing the beverage from the container by operating a tap which controls flow of the beverage through an aperture in the container characterised in that the container is filled to between 5/8 to 3/4 of its volume, in that the preparation of the dispenser for dispensing includes filling the head space above the beverage with gas under pressure comprising nitrogen at a pressure of 14 psi (95 x 10³ N/m²) above atmospheric and in that the dispensing of the beverage from the container is carried out without filling any further gas into the head space. A method as claimed in Claim 1 wherein the container is filled with the carbonated beverage to 5/7 of its volume. A dispenser for carbonated beverages prepared for dispensing in accordance with a method as claimed in either Claim 1 to 2. A dispenser as claimed in Claim 3 in which the container is made of polythene terephthlate. A dispenser as claimed in either Claim 3 or 4 wherein the container has two apertures, a first aperture for filling the container on the central axis thereof and for which sealing means are provided, the second aperture carrying a dispensing device and positioned adjacent the periphery of the end face, the container being located in use in a position where the dispensing device is as low as possible relative the central axis of the container.

Inventors: LANE, CHARLES A., LUCKING, ANTHONY JAMES
Applicants: WADDINGTON & DUVAL LIMITED
Application year: 1986
Main classification: B67D1
IPC codes: B67D1, B65D81