What does OESO stand for in bourbon?

Answered by John Watkins

When it comes to , there are many factors that contribute to its unique flavor profile. One of these factors is the strain used during the fermentation process. In the case of Four Roses Distillery, they use different yeast strains to create their various bourbons, and one of these strains is denoted by the term OESO.

The term OESO is an abbreviation that provides specific information about the yeast strain used in the production of a particular bourbon. The first letter, O, indicates that the bourbon is made at Four Roses Distillery. This is significant because each distillery has its own distinct production methods and techniques, which can greatly influence the flavor of the final product.

The second letter, E, denotes the specific yeast strain used in the fermentation process. In the case of OESO, this particular yeast strain imparts its own unique characteristics to the bourbon. Yeast is responsible for converting the sugars in the mash into during fermentation, and different yeast strains can produce different flavors and aromas.

The third letter, S, is common to all bourbons produced at Four Roses Distillery and simply indicates that the bourbon is Kentucky Straight Bourbon . This designation signifies that the bourbon meets the legal requirements for being labeled as a straight bourbon, including being aged for a minimum of two years in new, charred oak and meeting specific criteria for its mash bill.

It's important to note that the OESO yeast strain is just one of several strains used by Four Roses Distillery. Each yeast strain brings its own unique characteristics to the bourbon, and the combination of different yeast strains used in Four Roses' recipes allows for a wide range of flavor profiles to be created.

The OESO yeast strain, in particular, is known for contributing fruity and floral notes to the bourbon. These flavors can range from ripe berries and stone fruits to delicate floral aromas. The use of this yeast strain adds complexity and depth to the bourbon, creating a truly unique drinking experience.

As a sommelier and brewer, I have had the opportunity to taste bourbons made with different yeast strains, including those using the OESO strain. The differences in flavor that can be attributed to the yeast strain are truly remarkable. It's fascinating to see how something as seemingly small as the choice of yeast can have such a significant impact on the final product.

The term OESO in bourbon stands for the yeast strain used in the fermentation process. It indicates that the bourbon is produced at Four Roses Distillery and that the specific yeast strain used contributes its own unique flavors and aromas to the final product. The use of different yeast strains in bourbon production allows for a wide range of flavor profiles to be created, making each bourbon truly distinct and special.