GB979491A - Improvements in or relating to brewing of beer - Google Patents

Abstract

<PICT:0979491/C6-C7/1> <PICT:0979491/C6-C7/2> In a continuous fermentation process involving fermentation of a fermentable liquid (brewers wort) by yeast, the liquid is caused to flow along an ascending path through a liquid-permeable plug of yeast which is substantially unobstructed over its cross-sectional area and yeast which rises in the liquid is caused or permitted to flocculate within the flow path without being re-circulated externally thereof whereby the yeast is retained within the flow path. A strain of yeast capable of spontaneous flocculation should be employed. Wort from an inlet 25, Fig. 1, is fermented by a plug 32 of yeast in a fermenter 10 and fermented wort passes along an outlet pipe 26 to a collecting vessel 27. The fermenter, which may be inclined, for example at an angle between 9 degrees and 45 degrees to the horizontal, arranged vertically, or in the form of a helix having 3 1/2 turns or zig-zags composed of 3 or 5 straight lengths, is temperature controlled by the flow of water or air through a jacket 15 or by tape containing a resistive heating element (not shown). The outlet line 26 for the fermented wort has a branch feeding a removable sampling vessel 31. The rate of fermentation may be automatically adjusted by valves 23 and 24 in response to a detection of the quantity of carbon dioxide from the fermenter tube. Gas, such as carbon dioxide gas released from the vessel 27, is admitted through a line 22 to the fermenter wherein the bubbles 35 produced (for examples 1 - 10 ml. size for a fermenter 1 inch in diameter) serve to release gas bubbles from the yeast cells or clumps, thereby aiding flocculation. Alternatively, these bubbles may be released by applying a vibrating member to the liquid or by establishing pressure vibrations of gas adjoining the liquid in the flow path at its upper or lower ends. A substantial quantity of oxygen is admitted to the liquid when it is desired to establish aerobic fermentation promoting yeast growth; the yeast obtained may be removed continuously or periodically from either the upper or the lower end of the flow path. In a further embodiment, fermenter tubes 11. Fig. 2 and Fig. 3 (not shown), are arranged vertically in a circle and communicate with inlet and outlet chambers 43 and 44. Individual tubes may be cut out by valves 40, 41, for cleaning and sterilizing with steam. Operational examples are given.