Temp Move

Terminology and Combining Techniques

The techniques used by brewers to create sour, funky, and wild beers often blur the lines between different established techniques. This makes it difficult to always put a box around a given brewer's process. For example, some brewers will use an open vessel such as a coolship to cool their wort overnight, and collect ambient microbes from the surrounding environment similar to how spontaneous fermentation is done, but also will add cultures from a laboratory afterwards. Some brewers will use a kettle souring process to create acidity up front, and then pasteurize the beer and age it in a barrel without Brettanomyces, thus creating an acidic beer with residual sugars. Some brewers may first sour wort, not pasteurize it, and then add S. cerevisiae and Brettanomyces to the beer to finish the fermentation, and then either steel ferment or barrel ferment the beer. The ways in which different techniques can be combined are too many to list, and are constantly evolving with the creativity of brewers.

In addition to the overlap of different processes, there are also other unresolved issues with labels such as "wild" or "spontaneous". For example, Is a beer only considered "spontaneous" if it is cooled in a coolship, or is it also "spontaneous" if the wort is simply transferred to a barrel that previously held a beer that was inoculated only by ambient microbes from cooling in a coolship? Are microbes that are wild caught from fruit or flowers and then isolated and cultured considered "spontaneous" or "wild" or something else? Some terminology is still up for debate and evolving as brewers continue to discuss them.

Both of these issues not only make talking about sour/funky brewing difficult between brewers, but they also make it even more challenging to communicate to consumers what it is the brewer is doing to make the beer that they are drinking, and why that process is important. Efforts by professional brewers have recently been made to begin discussing these terms, and what effects on the market various terms might have. For example, brewers who barrel age sour beers are often critical of other brewers who produce kettle sour beers within 2 weeks and charge prices that are comparable to barrel aged sour beers. On the other side of the discussion, brewers who sour wort are critical of the term "kettle souring" being portrayed as only a "shortcut" or a way to make "one dimensional sour beer", and thus causing consumers to perhaps view kettle soured beers in a negative light despite the unique beers that can be created from such a process (Gose and Berliner Weissbier are not the only styles that can be brewed with wort souring or kettle souring techniques). Indeed, brewers who are passionate about souring wort often know just as much (and sometimes more) than brewers who use only mixed cultures, and can create both desirable and very unique beers.

As an example of discussions regarding these challenges, see this panel with Jeffrey Stuffings of Jester King Brewery, Jeff Young of Blue Owl Brewing, Brandon Jones of Milk the Funk and Yazoo Brewing Company (mostly MTF), Jay Goodwin of The Rare Barrel, and Michael Lalli of Prairie Artisan Ales (audio improves around 27 minutes):