Cover of FAQ: If the Yeast Ain't Happy, Ain't Nobody Happy: The Microbiology of Beer

What do microbes have to do with beer? Everything! Because the master ingredient in beer is yeast—a microbe—and every step in the brewing process helps the yeast do its job better. A new freely available report "FAQ: If the yeast ain't happy, ain't nobody happy: The Microbiology of Beer" explores the synergy between microbiology and brewing beer.

"Every time someone brews a batch of beer, in a very real sense he or she is doing a microbiology experiment. If you brew beer at home, you’re a microbiologist," says Dr. Charles Bamforth of the University of California, Davis, a member of the steering committee that produced the report.

The American Academy of Microbiology brought together some of the world’s leading experts on yeast, brewing and food science to explain how making great beer depends on creating the perfect conditions for yeast to work its magic. Keeping the yeast happy, it turns out, is what will make or break your beer batch.

"FAQ: If the yeast ain't happy, ain't nobody happy" is based on the deliberations of 18 participants who convened for a day to discuss the relationship between microbiology and beer brewing.

The FAQ answers the following 6 common questions:

  • What does microbiology have to do with beer?
  • What’s so special about brewer’s yeast?
  • Is all brewer's yeast the same?
  • How is beer made?
  • How does the yeast affect the beer?
  • Is it really all about the yeast?

All of the answers are straightforward and limited to 2 pages each for easier understanding. Important terms and concepts are introduced as needed and fully explained. Sidebars on topics like the domains of life and fermentation round out the 12-page report.

"FAQ: If the yeast ain't happy, ain't nobody happy" is part of a series of reports designed to provide easy-to-understand explanations about the roles microbes play in the world, from cleaning up oil spills to causing epidemics, to producing many useful products. The FAQ reports are based on the deliberations of 15 to 20 microbiology experts who meet for a single day to develop answers to frequently asked questions about a specific topic.


Ann Reid, Michael Ingerson-Mahar. 2013. FAQ: if the yeast ain't happy, ain't nobody happy: the microbiology of beer.

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