Most whiskey fans know something about the grains that go into their favorite tipple, but what about whiskey yeast? The industry uses a number of different types of yeast, with practices varying by region and whiskey category.

In the bourbon industry, most distilleries dedicate a lot of energy to maintaining a proprietary yeast culture that they say makes a major impact on flavor. (Some, like Four Roses, maintain several). Those yeast cultures are propagated on an ongoing basis, with each new batch of bourbon beer inoculated with pitches from the mother culture.