Are you a fan of sour or gose style beers? With sour beers rising in popularity and a few of our sours being among our top requested beers, many have asked – what is it that makes a sour beer sour? We are here to tell you just that!
First, let’s talk about yeast. When beer is made, the wort is fermented with a species of Saccharomyces yeast. During this process, the yeast consumes the sugars in wort to produce alcohol and carbon dioxide, as well as a variety of different flavor characteristics. Traditionally, fermentation is temperature controlled so that the beer being made has a consistent taste. When it comes to sour beers however, they are fermented with an acid producing bacteria called Lactobacillus. Lactobacillus produces the tart lactic acid that is what makes the beer sour. Depending on the process, a wild yeast Brettanomyces and another bacteria, Pediococcus, can also be found in the fermentation. Brettanomyces, often referred to as “Brett” yields complex flavors from earthy and funky to tropical fruit all developed during the fermentation process. Pediococcus also produces lactic acid, but it is much slower and fermentations can take months.
Second, process is key to creating a sour. There are a couple of popular production processes in the United States that can produce a beer sour.
The first process, which is probably the most common and is also how we produce our sours, is kettle souring. In typical beers, the souring bacteria and yeast are undesirable. So, to protect the other beers, the wort is soured in the kettle by pitching in Lactobacillus and letting it ferment for about a day. The sour wort is boiled to kill all the bacteria and then the wort is fermented by Saccharomyces and ready for packaging just like all our other beers in about 2 weeks.
A second process is a secondary fermentation. The wort is fermented normally with Saccharomyces and then it is transferred to wood barrels or fermenters called foeders. Fruit or another source of sugar is added and any combination of Brettanomyces, Lactobacillus, and Pediococcus is pitched. Secondary fermentations can take 12-18 months.
A third process is a mixed fermentation. The wort is pitched with any of or all four microbes at the same time or allowed to “naturally” ferment in open-top fermenters, also known as coolships. Again, these fermentations can take months and require large rooms dedicated to just that beer.
While sour beers are more difficult to brew, they have become a staple brew in many breweries today, including at Ignite. Our Women on the Rise, a blackberry lime gose that was originally brewed in March 2019 on International Women’s Day, falls into this category, and has been a crowd favorite ever since. Since then, we’ve expanded our rotating sour line to include many seasonal favorites including:
- Women on the Rise – Blackberry Lime Gose (as mentioned!)
- Don’t Stand So Gose – Blueberry Lemon Gose
- Staycation Sunset – Tangerine Pineapple Gose
- Cherry Gose with Anything – Cherry Lime Gose
- THA BLESSING – Cranberry Pomegranate Gose
Stay tuned for tapping news and can releases of some of your favorite Ignite goses throughout 2021!