Brettanomyces Claussenii was originally isolated from English stock ale by its namesake, N. Claussen. While this strain does produce the classic Brett "horse blanket" , leathery and somewhat smoky notes, they are more subdued when produced by this strain than by other Brett strains. Other aroma and flavor compounds round out the classic Brett character, with tropical fruit notes of pineapple and, to a lesser extent, peach and blueberry. Brett Claussenii can be used as the primary strain for fermenting, but is often used after a primary fermentation with an S. cerevisiae strain, and in blends to produce sour beers. It is highly attenuative, given proper time to fully ferment out, and is known to create a pellicle during fermentation.
| Brand | Wyeast |
| Beer Styles | Lambics |
| Alcohol Tolerance | 12% ABV |
| Attenuation | 80% |
| Flocculation | Low |
| Cell Count | 100 Billion |
| Temperature Range | 60-75F |