Lesson 3 of 11 · 10 min
Fermented beverages
NCERT §8.2, §8.2.1
Tuesday: a chemistry teacher shows the class a photo of steel tanks as tall as a house at a factory. They hold nothing but yeast, sugar and water, and they are working.
The lesson in notes
In short
Industrial production needs microbes grown in very large vessels called fermentors.
Yeasts have been used since ancient times to make wine, beer, whisky, brandy and rum.
The yeast used is Saccharomyces cerevisiae, the same species used in bread-making; in brewing it is called brewer's yeast.
It ferments malted cereals and fruit juices, producing ethanol.
The kind of drink depends on the raw material fermented and on whether the fermented broth is distilled.
Wine and beer are made without distillation. Whisky, brandy and rum are made by distilling the fermented broth.