Many whisky connoisseurs seek out single malts produced by now-defunct Scottish distilleries, endeavoring to find rarities of exceptional quality. In 2014, William Grant & Sons capitalized on this predilection by launching Rare Cask Reserves, a venture spearheaded by master blender Brian Kinsman that bottles and blends the company’s stock of mature whiskies sourced from bygone distilleries. The most recent offering, Rare Cask Reserves Ghosted Reserve 26 Year Old (williamgrant.com, $400), is a blend of malted whiskies from two shuttered distilleries: Inverleven, which operated from 1938 to 1991, and Ladyburn, which operated from 1963 to 1975. Aged in oak casks, the whisky imparts sweetness on the nose and the palate. The blend also marries fruity and floral notes from the Inverleven with the Ladyburn’s great depth of flavor. Rare Cask Reserves produced 4,100 bottles of the spirit; 2,000 were recently released in the United States.