According to a label filed with the Alcohol and Tobacco Tax and Trade Bureau (TTB), Bruery Terreux is working on releasing Rum Barrel-Aged Tart of Darkness, a 9.7 percent ABV sour stout aged in rum barrels before being packaged in 750ml bottles. As its name suggests, new beer uses the Placentia, Calif.-based brewery’s Tart of Darkness as its base that debuted in 2013.

There have been multiple incarnations of the sour stout since 2013, including Tart of Darkness with Black Currants (6.2 percent ABV), Tart of Darkness with Cherries & Vanilla (7.1 percent ABV) and Tart of Darkness with Raisins (6.6 percent ABV.)

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