Great Divide Brewing Co. knows that 21 years in business is a big deal in the alcohol world, and is celebrating the best way it knows how: by releasing a new beer.

The Denver, Colo.-based brewery will be releasing 21st Anniversary, a 6.2 percent ABV “American sour” that is brewed with both lactobacillus and brettanomyces before being aged in wine barrels for nine months.

“This American sour is a celebration of 21 years of brewing with Bold Character,” says a press release. “This commemorative release opens up with bright, tart, kiwi and citrus notes before mellowing out with a hint of oak and subtle white wine-like character.”

According to a press release and a label filed with the Alcohol and Tobacco Tax and Trade Bureau (TTB), the new limited release will be packaged in 750ml bottles and will be available for sale at Great Divide’s 21st Anniversary event on June 13. An email sent to the brewery for additional details was not immediately returned.