According to a label filed with the Alcohol and Tobacco Tax and Trade Bureau (TTB), Allagash Brewing Co. is working on releasing the newest version of Coolship La Mûre, a 7.7 percent ABV spontaneously fermented ale aged in oak barrels with blackberries that will be packaged in 375ml bottles. The sour will be the latest in Portland, Maine-based brewery’s Coolship Series, which also includes Coolship Red, Coolship Cerise and the recently debuted Coolship Pêche.

A koelschip—or coolship, as it is more commonly known in America—is a large, shallow steel pan about a foot deep that is used to both cool down wort after it is brewed and to expose the resulting concoction to naturally occurring yeasts and bacteria that are in the air. A number of U.S.-based breweries incorporate coolship beers into their lineups, including Jester King Brewery, Allagash and The Collective Brewing Project.

An email sent to the brewery for additional information was not immediately returned.