The Italian digestifs known as amari date back to the thirteenth century, when monks began making them for medicinal purposes. These bracing after-dinner liqueurs—“amaro,” the singular of “amari,” means “bitter”—are at once ubiquitous and highly localized in Italy, with towns creating proprietary mixes of macerated herbs that are then fermented in neutral liquor. Consumption of amari, whether it’s mixed into drinks or served neat, gained traction in the United States during the craft-cocktail boom of the early aughts, with brands such as Aperol, Campari, and Fernet-Brancabecoming especially popular. Eventually, distillers in the U.S.—and Texas—began to make their own versions. “Amari give the distiller free rein,” says Brian Meola, the chief executive officer of Revolution Spirits Distilling Co., which debuted the first Texas amaro, Amico Amaro, in…