They bring a crisp bitter complexity to any cocktail, the perfect additional oomph to a whiskey on the rocks in the dead of fall. Tuthilltown Spirits (the guys behind the award-winning Hudson Whiskeys) did good with Bitter Frost Basement Bitters, which has actually been available since last fall — but only if you made the trek to the distillery in New York state or stumbled across it at their smalltime online store. The 92 proof mix-in is now widely available through a number of distributers, for $20. Their bottling crew brought together a special blend of unaged rye spirit, Sarsaparilla, and fourteen other herbaceous and botanical goodies for a spice-heavy yet somehow-light base, then balanced it with sweet local maple syrup before aging it in one of their cured barrels. That's a process that dumbed down for our purposes reads: "damn tasty."