MANUFACTURING OF YEAST.
Sugar is the favourite food for yeast, in the production of yeast; molasses is used to provide this sugar source. Cane molasses or beet molasses can be used however some manufacturers prefer the mixture of the two.
Yeast is first clarified and sterilized before molasses are fed to it so s to assure the final yeast colour and also to prevent bacteria and other organisms from being introduced during manufacturing process.
The molasses is diluted with water, adjusted for acidity and heated until almost boiling then filtered.
The seed yeast is a maintained laboratory culture so as to avoid contamination by wild yeast present in the air then they are selected to according to the yeast that is going to be produced and specific characteristics that are required.
The seeds are normally placed in small flasks where they are given time to grow, then transferred in different steps from these small flasks to tanks of about 4000 litres in volume.
It is now known as stock yeast where it is separated from the alcohol generated by fermentation and stored in refrigerated tanks for subsequent fermentation cultivation.