Kettle Sours, also called ‘quick sours’, are tart beers that feature lactobacillus, or “lacto”. This bacterium is a probiotic that converts sugars to lactic acid. It’s the same live culture you’ll find in unsweetened yogurt. “Kettle” refers to the brew kettle, meaning the beer is soured in a stainless-steel brewing vessel and fermented in a similar tank. This denotes the key difference between kettle sours and traditional sours: there are no barrels involved in the making of kettle sours.
The fact that kettle sours never see a barrel is advantageous to many brewers. You can get a tart flavor in just a few days, versus months or years, and therefore for a fraction of the price of barrel-aged sour beers. This also makes kettle souring slightly controversial in the brewing world. Kettle souring “is very one-note,” Chad Yakobsen, founder of Crooked Stave Artisan Beer Project, told the Denver Post. “It doesn’t have the time and artistry in it [that a traditional sour does].” In short, Yakobsen said, “it is not my thing.” Others view this technique, which is a version of souring that has been used for centuries, as just another tool that brewers have at their disposal to add flavor to beer. It affords them more creativity, it’s cheaper, and a much faster process.
No matter what type of kettle sour you’re having, the flavors are bright, acidic, tart, lemony, and refreshing!
Gose (pronounced “goh-zuh”) and Berliner Weisse have both seen recent revivals in the U.S. craft brewing scene. While both are German wheat ales that have been soured by Lactobacillus, they each have their own unique characteristics. Gose, which gets its name from the town in which it was first created, Goslar, is brewed with salt and coriander. Those flavors are subtle, and match the level of sourness in this highly refreshing beer.
Berliner Weisse expresses more acidity, but is even lower in alcohol (traditionally between 2.8 and 3.8% ABV) than Gose (4.2 to 4.8%). When served in bars and restaurants, Berliner Weisse is often served “mit schuss,”; literally “with a shot” of woodruff or raspberry syrup. American brewers have taken to short-cutting this step by making fruited variants in the brewery.
There are many examples of craft Berliner Weisse styles being brewed today; Jack’s Abby Craft Lagers has a Cranberry Berliner Weisse, Off Color makes Fierce Berliner Weisse, Professor Fritz Briem’s 1809 is a widely available Berliner Weisse from Germany, but clocks in a higher than average ABV (5.0%). And Bayerischer Bahnhof also makes a high quality and widely available, imported Berliner Weisse that has recently been canned for the first time. And if you’re looking for a schuss, Jo Snow Syrups makes an authentic Woodruff syrup available at some Craft Beer Cellar stores, as well.
For the Gose style, Anderson Valley Brewing makes a series of Goses, including Briney Melon, Blood Orange, and Framboise Rose, and Two Roads Brewing has their Tanker Truck series of Goses, including Passionfruit, Persian Lime, and Sauvignon Blanc. Other examples include Avery Brewing El Gose, Victory Kirsch Gose, Left Hand Wheels Gose Round, Boulevard Hibiscus Gose, Union Craft Brewing Old Pro Gose, and Off Color Troublesome Gose. In addition to their Berliner, Bayerischer Bahnhof makes a high-quality, widely available Gose from Germany. Ritterguts also makes an excellent imported Gose.
There are also beers like the fast-growing Dogfish head Seaquench; described as a cross between Gose and Berliner Weisse, and have dubbed it a “session sour”. Another example of a Kettle Sour not called a Gose or Berliner is Penrose Brewing Company’s Session Sour.
Kettle sours afford brewers around the world a way to make a refreshing, tart, drinkable beer pretty quickly and economically. Have you had one this summer?