The Sweet Tart of Beer

Lemon drops, Sour Patch Kids, Warheads, and more, sour flavors are popular for all kinds of treats. And while sauerkraut and kimchi are also sour, their flavor is quite different from Sour Patch Kids. You'll also often see sour beers, which are different than everything else mentioned so far. So what do all those things have in common?

What makes them sour?

Acid!

But not just any type of acid...

Citric acid and malic acid are types of acid used in food to give that puckering sensation, and you can even buy bags of pure food-grade acid to make your own tart treats. Fermented foods, like sauerkraut, make use of wild bacteria to produce lactic acid, which gives them that classic sour "twang." Sour beer uses a very similar bacteria process, but with malt instead of cabbage.

To brew a sour beer, we actually start the brew like normal. We steep the grains in hot water and strain the liquid into the boil kettle and we even boil that liquid for about 20 minutes to make sure there are no foreign bacteria strains that we do not want in our brew. Then we cool the liquid to a tolerable temperature and add a special strain of bacteria to produce acid in the brew. This occurs when the bacteria lowers the pH level and the brew becomes more acidic. After it's reached an appropriate pH level, the beer brewing process continues and the wort is boiled to kill off any bacteria and hops are added before a normal brewing yeast is pitched, finishing out the flavors and turning any remaining sugar into alcohol.

This process typically takes 48-72 hours!

Our rotating sour beer, "FruiTart," is a "kettle" sour. In addition to using bacteria that's been selected to ferment with a sour flavor, we also add lactic acid directly into the brew kettle during the process. This helps us control exactly how tart the final beer is, and means we can make the same beer taste the same each time. With the addition of fruit to balance out that sour taste, you get a crisp and refreshing brew!

You can also "wild ferment" sour beer, which is just what it sounds like: allowing wild yeast found in nature to ferment with a unique taste. (This is typically how sourdough bread starts!) That process is a bit more art than science, and requires a lot of safeguards to make sure the wild yeast doesn't spread around the whole brewery and make every beer sour! Wild fermented beers can also have more unique flavors, with some descriptions like "horse blanket" and "damp straw"...YUMMY!

Whether you're a sour fan or just dipping your toe in the mouth-puckering world of tart beer, you've got both yeast AND bacteria to thank for your favorite sour brews!

CHEERS!