Differences Between Baker's & Brewer's Yeast

Baker's yeast refers to yeast used in the baking of foodstuffs, while brewer's yeast refers to yeast used in the fermentation process of alcoholic beverages.

Species

Saccharomyces cerevisiae, the most common species of yeast, is used as both baker's and brewer's yeast. While the species of yeast is the same, different strains are often used to produce a sweeter taste in baked goods and a more bitter taste in brewed goods. Other species, such as Saccharomyces bayanus or Saccharomyces pastorianus, are generally used in alcohol fermentation only.

Function

The key function of yeast in baking is the leavening of dough, whereby the yeast turns sugars into carbon dioxide bubbles and causes the dough to rise. Yeast used to create alcoholic beverages enables alcoholic fermentation, whereby sugars are converted into ethanol.

Health Supplement

Yeast is also sold as a health supplement as a source of B-complex vitamins, selenium and chromium. Typically, these supplements are labeled as "brewer's yeast"; however, these are often non-bitter strains of yeast and can contain nutritional or flavor additives.

History

In 1859, Louis Pasteur discovered how yeast works while observing how dust on grapes reacted. He also discovered that yeast is living and that only active yeast leads to fermentation.

Fun Fact

Brewer's yeasts fall into two categories: top fermenting and bottom fermenting. Top-fermenting yeasts create a foam on the top of the wort and result in a sweeter beverage. Bottom-fermenting yeasts result in a more brisk-tasting beverage.

References

• BBC: The History of Bread Yeast
• University of Maryland Medical Center: Brewer's Yeast
• International Journal of Systematic and Evolutionary Biology: Analysis of the Constitution of the Beer Yeast Genome