What Are Sour Beers?

by Kevin on May 14, 2013

What Are Sour Beers?

The craft beer market today in America is filled with beer geeks seeking out some of the best Double IPAs, Imperial Stouts, and Sour beers available. If you are not really familiar with sours, you may have noticed that neither the name nor style states that the beer is actually a sour ale.

The sour ale category is broken down by a number of the different styles of beer:

American Sour/Wild Ale – Russian River Brewing Company Supplication
Berliner Weisse – Professor Fritz Briem 1809 Berliner Weisse
Faro – Lindermans Faro Lambic
Flanders Red Ale – Rodenbach Grand Cru
Fruit Lambic – Boon Oude Kriek
Gueuze – Boon Oude Gueuze
Oud Bruin – Liefman’s Goudenband
Unblended Lambic – Cantillon Iris

The key to making a beer taste tart, acidity, or funky is the type of yeast and bacteria a brewer may use. For most brewers, sanitation is the most important part of their brewing process. However sour beers are produced by using the same wild yeast strains and bacteria that most brewers are trying to keep out. Wild yeast strains will provide the beer with a funky taste, while it is the bacteria in a beer that will develop the sour flavor.

While brewing, some brewers in Belgium and even Allagash in the US transfer hot wort (unfermented beer) to an open-air container referred to as a koelschip to allow the wort to cool for 12 to 24 hours. While in the koelschip, wild yeast and bacteria in the air will cling to the cooled wort creating a spontaneous fermentation.


Other breweries will use certain types of canned or dried fruit during the fermenting stage to add wild yeast and bacteria into their beer. Most American brewers can purchase wild yeast strains such as Brettanomyces, Lactobacillus, and Pediococcus commercially and pitch them directly into the fermentor to add new flavors to their beer. These styles of beers are traditionally added to oak barrels where they will age and develop for several years.

Krieks and Framboises are types of Fruit Lambics that are fermented with cherries or raspberries, these types of fruits are the vessels in which wild yeasts are added to produce a more sour taste. The Linderman’s version of these styles are actually sweetened with additional sugar for this style to appeal to the American palette.

A Gueuze is a style that is a blend of several Lambic beers ranging in different ages of the same beer or blending several completely different Lambics. Cantillon’s Classic Gueuze is a blend of one, two, and three year old Cantillon Lambics that are fermented and stored centuries-old oak casks. Once blended, the beer is bottled and the combination of different years of Lambics creates a second round of fermentation inside the bottle. Oude Gueuze Tilquin à L’Ancienne is example of a Gueuze that is blended with wort from Boon, Lindemans, Girardin, and Cantillon. Gueuze Tilquin purchases the wort from these other Lambic breweries and blends them together to develop a very unique beer that is fermented and stored in oak barrels for several years.

As the craft beer industry evolves, we have seen several trends transpire over the years from hop bombs, to bourbon Imperial Stouts, and now we are witnessing the canning revolution. While most sours produced are from Belgium, American craft brewers are continuously looking at ways to innovate and produce more creative and complex beers. Sour beers are risky and take time to develop, but if their customers embrace the funk, they will brew it.

Sour Beer – Wikipedia
Gueuze – Wikipedia

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