Yeast are rarely the focus of any spirits conversation.
Commercial distiller’s strains are the go-to, and they’re not typically one of the components considered open to interpretation. They promise consistency, acting as a control for any variables in raw materials, distillation choices, and botanicals or other additions. Even in-the-know drinkers are more likely to be interested in factors such as the grain or fruit base or the aging process (if there was one).
However, for some spirits still made with traditional methods—such as rum or tequila—differentiation of yeast via the cultivation of wild strains and open-top fermentation has always been on the table. Plus, a small number of whiskey distillers have more recently been embracing ambient yeast as another lever to pull for distinguishing their spirits.
When you’ve nailed down your malt, your distillation process, and your aging, fermentation is a major remaining field of opportunity. It contributes unique flavors beyond what drinkers are used to from the grain or aging. It can also impart some terroir—some character that comes from your distillery’s location.
Wild yeast require a significant level of quality control, but they can yield a spirit quite literally like no other on any shelf. Let’s look closer at how today’s distillers are managing these cultures.