Fire Tincture by Scrappy's

Scrappy's makes its bitters in small batches in Seattle and names Fire Tincture its best-selling bottle worldwide. It blends five chiles, with fresh habanero in front, so a dash gives the same heat every time.

Fresh habanero leads, with four other chiles behind it, and the heat is clean and the same from one dash to the next. It is very hot: one dash changes a drink.