100% Brettanomyces Fermentation

100% Brett fermentations typically create a fruit forward beer that is less funky than if the Brettanomyces is pitched into a beer that has first been fermented with Saccharomyces.

General Information

The method of fermenting wort with only Brettanomyces was popularized by Chad Yakobson's Brettanomyces Dissertation on the Brettanomyces Project blog. While primary fermentation with Brettanomyces is a complex subject due to the wide range of characteristics of different species and strains of Brettanomyces, in general beer that is fermented with Brett in primary usually produces a surprisingly clean, fruity beer. For this reason, wort that is characteristic of American IPA has been found to create wonderful beers when primarily fermented with Brett.

Typical characteristics of Brett primary fermentations (these are generalizations, and may not be true for every strain):

• Lack of the typical "horsey", "funky", "barnyardy" flavors due to the lack of Saccharomyces esters/phenols (see the Brettanomyces Metabolism page for more information).
• Light fruit characteristics.
• A longer lasting hop aroma and flavor due to Brett's ability to constantly metabolize micro-oxygenation.
• A lack of glycerol, which is a compound that Saccharomyces produces which gives beer it's slick mouthfeel. Malts such as oats or flaked wheat are often used to make up for the lack of glycerol.
• Since Brett generally does not flocculate as well as Saccharomyces, cloudier beers are often produced if filtering is not used.
• Slightly longer primary fermentation in general (3-6 weeks).
• Perceived bitterness may be quite a bit lower than the same wort fermented with a clean ale yeast.

Brewing Techniques

Starter Information

When relying on a Brettanomyces culture for primary fermentation, a starter will often be necessary due to the fact that most yeast labs provide a small cell count for their Brettanomyces cultures. See the Brettanomyces Starter Information section for more information on Brett starters.

Wort Production

American IPA or American Pale Ale recipes are a tried and true general approach to making wort that is favorable to 100% Brett fermentations. Fruitier hops such as citra, mosaic, galaxy, etc. tend to compliment the light fruity characteristics of a Brett primary fermentation. The addition of body-increasing malts such as oats or carapils may assist with the lack of glycerol that is typical of Brett, but isn't always necessary. Otherwise, wort production can remain the same as it is for an American IPA/Pale Ale recipe.