There are several brewing methods that are specific to sour and wild brewing. Different methods can be used separately or in conjunction with each other to help produce a desired result, or to produce a certain style of beer. For example, Berliner Weissbier is often brewed using the sour mashing or kettle souring methods. Another example is that kettle soured beers can be barrel aged with or without Brettanomyces. By mixing different techniques for different specific reasons, brewers have created new and interesting results.
General Fermentation Techniques
- Mixed Fermentation refers to the process of fermenting a wild or sour beer with a culture that contains more than just Saccharomyces (or no Saccharomyces). These are often mixed cultures containing Brettanomyces, Saccharomyces, Lactobacillus, and Pediococcus. Mixed cultures are available from multiple yeast companies such as Wyeast, White Labs, The Yeast Bay, GigaYeast, and Omega Yeast Labs.
- Wort Souring is similar to sour mashing, except the brewer often uses a pure culture instead of adding grain to the kettle. Instead of souring the mash, the wort is transferred to the boil kettle and soured usually over the time span of 1-3 days with a pure culture, or with the wild yeast and bacteria found naturally on grain (grain is added to the kettle). Similar to the sour mashing process, the soured wort is usually boiled to heat pasteurize the wort (a process called "kettle souring").
- Sour Mashing is a method that uses the wild yeast and bacteria that is naturally present on grain to quickly create acidity in a mash usually over a time span of 1-3 days. The soured wort is afterwards generally boiled to kill off the microorganisms that were present in the sour mash.
- Brettanomyces and Saccharomyces Co-fermentation refer to processes of using Saccharomyces and Brettanomyces, and no souring bacteria. This results in a funky beer with interesting flavors from the Brettanomyces, but very low to no levels of acidity.
- Spontaneous Fermentation refers to the method of using yeast and or bacteria that is naturally present in the air, or on fruit, grain, insects, or other naturally occurring carriers.
- 100% Brettanomyces Fermentation is the process of doing a primary fermentation with only Brettanomyces yeast.
- Commercial Sour Beer Dregs Inoculation is a process where unpasteurized commercial sour beers are used to ferment a sour beer. Generally only the last half inch of a beer is used, which is sometimes called the "bottle dregs". Commercial sour beers can be used by themselves, but are more often used in conjunction with another brewing method to add diversity to a mixed fermentation.
- Solera is a fermenter management process that involves removing a portion of aged beer/wine/etc from a fermenter, and refilling that fermenter with younger beer/wine/etc. Traditionally solera systems involve multiple tiers of aging product and the refilling is accomplished from the next oldest tier. In beer production, it is more common to have only one vessel and to refill with fresh wort or young beer. The removed portion can be used in a variety of ways, including but not limited to filling up a second stage solera fermenter, blending with another beer, packaging the beer, or given additional aging on fruit or spices.
- Cereal Mashing is the process of gelatinizing adjunct grains such as corn, rice, and unmalted wheat, so that their starches may be converted during a saccharification rest.
- Turbid Mashing is a traditional mashing technique used in Lambic production that produces a very starchy wort for long term mixed fermentations with Brettanomyces.
- For other pages for specific processes used in mixed fermentation beers, see the Table of Contents.
- Raw Ale is a brewing process where wort is not boiled or boiled for a very short amount of time.