BJCP 28B · American Wild Ale
Mixed-Fermentation Sour Beer
A mixed-fermentation sour beer with yeast, Brett and lactic bacteria: complex and dry, with acidity that blends into the base.
This is a specialty category, so it has no numbers of its own. Gravity, bitterness, color and alcohol are those of the base style you choose, plus whatever the special ingredient or process adds.
What Mixed-Fermentation Sour Beer is like
A sour beer fermented with a mix of yeast, Brettanomyces and lactic bacteria, with low to high acidity and a funky character that adds complexity. It starts from a base style that doesn't have to be a classic one.
Appearance
Varies with the base. It may be a little hazy. The head often doesn't last long.
Aroma
Lactic sourness with Brett notes such as fruit, leather or barnyard over the base. Acetic sourness, if present, should be very subtle.
Flavor
Clean, low to high lactic sourness, with Brett complexity and the base style's malt in the background. Dry finish. No strong vinegar, no ethyl acetate and no fermentation faults.
Mouthfeel
Light to medium body, usually dry. Moderate to high carbonation.
Where Mixed-Fermentation Sour Beer comes from
American craft breweries started imitating Belgian sours with mixed fermentations and barrel aging, and ended up developing their own style. Today it's brewed all over the world.
Ingredients
Those of the base style, with Saccharomyces yeast, Brettanomyces, Lactobacillus and Pediococcus, often from mixed cultures or bottle dregs. Low hops so they don't hold back the bacteria.
Brew it yourself
How to brew Mixed-Fermentation Sour Beer at home
Use a commercial mixed culture or the dregs of unpasteurized sour beers, and be patient: it usually takes anywhere from six months to more than a year. Limit oxygen during aging to avoid vinegar. State the base style when you enter it; judges look for sourness and funk that are integrated with the base rather than covering it up.
Food pairing
Mussels, goat cheese salad and dry-cured sausage.
Glassware: Teku glass, a tasting glass that works with almost any style.
Frequently asked questions
What food pairs well with Mixed-Fermentation Sour Beer?
Mussels, goat cheese salad and dry-cured sausage.
Which styles are similar?
If you like it, also try Brett Beer, Flanders Red Ale and Lambic.
If you like Mixed-Fermentation Sour Beer, try these
Classification and statistics: official Mixed-Fermentation Sour Beer guidelines from the BJCP, 2021 edition. Original text by Hacer Cerveza Casera.