Controlling alcohol fermentations

Abstract

In the initial stages of a fermentation of carbohydrate to form alcohol, the growth of the yeast is controlled by monitoring the pH value of a fermenting liquid or wort and controlling the supply of oxygen to the fermenting liquid or wort in accordance with the pH value. Preferably the temperature of the fermenting liquid is also controlled in dependence upon the pH value of the fermenting liquid or wort. It is particularly preferred that the control of the fermentation process is carried out automatically by an apparatus including a fermentation vessel 1, a pH sensor 8, 9, 10 arranged to provide an output signal representative of the pH of the liquid in the vessel 1, memory means to store information on the required pH with regard to the fermentation time, means 11, 12, 13 to inject oxygen into the fermenting liquid and control means 15 to compare the output signal of the pH sensor at a particular time with that of the required pH at that time, and, in the event of the pH of the fermenting liquid lagging behind that required, actuate the means 11, 12, 13 to inject oxygen into the fermenting liquid to increase the oxygen content of the fermenting liquid.