Louis Pasteur · Science

Fermentation Is Life

How Pasteur overturned the reigning chemical theory of his age by proving that fermentation - the turning of sugar into alcohol, of milk into sour, of wine into vinegar - is not a dead chemical breakdown but the work of living microorganisms. It was the discovery that launched microbiology and led him straight to the germ.

What you'll be able to recall

You learned that Pasteur showed each kind of fermentation is caused by a specific living microorganism, against the chemical orthodoxy that fermentation was mere chemical decay. In your own words, explain the evidence Pasteur gathered - yeast cells, the souring organism, the role of air - and why this discovery is the…

Leads to Justus von Liebig.

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