Write short notes on the following.
Brewer's yeast

Explanation

Brewer's yeast :
(i) Saccharomyces cerevisiae commonly called brewe's yeast is used for fermenting malted cereals and fruit juices to produce various alcoholic beverages. Wine and beer are produced without distillation, whereas whisky, brandy and rum are obtained by fermentation and distillation.
(ii) Oenology is the science and study of wine and wine making. Wine is made from the fermentation of grape juice. Grape juice is fermented by various strains of Saccharomyces cerevisiae into alcohol.
(iii) Beer is produced from germinated barley malt grain by Saccharomyces cerevisiae. Rum is made from fermented sugarcane or molasses or directly from sugarcane juice by Saccharomyces cerevisiae. Whisky is made from fermented grain mash by Saccharomyces cereivisiae.
(iv) Saccharomyces cerevisiae is the major producer of ethanol `(C_(2)H_(5)OH)`. It is used for industrial, laboratory and fuel purpose.