Cutty Sark Prohibition Edition was created to celebrate Captain William McCoy who supposedly smuggled Cutty Sark into the the USA during prohibition. He was renowned for never cutting his liquor and always delivering the good stuff which was dubbed “the real McCoy”. There’s no way to validate whether Captain McCoy ever smuggled in Cutty Sark, but he was an actual rum-runner during prohibition (bootlegger). However the term “the real McCoy” is more often accredited to a story involving an early 1900’s bare knuckle boxer named Kid McCoy, though even that’s in dispute and term could originate even earlier.
So what’s the difference between this and regular green bottle Cutty? According to their site: “whilst our regular Cutty Sark blend is 40% ABV. This is a “small batch” blend of the finest single malts and top-quality grain whiskies. Hand-selected American oak casks give subtle signature flavors of vanilla and citrus fruits…” Which isn’t super helpful , but the press release basically says it’s supposed to have more malt in the blend and married in 100% ex-Bourbon casks.