"We like to describe Thunderbolt as a neighborhood bar that just happens to have to amazing cocktails, which also applies to their simple but sneaky good espresso martini on draft. Vodka, sherry, and cold brew concentrate are mixed and kegged, then poured from a nitro tap like a pint of Guinness. The result is a velvety drink with a frothy head that takes seconds to serve, which means no waiting for a surly bartender to fire up the La Marzocco. Thunderbolt also mixes up their formula every so often: their current “mocha” martini adds in cacao-flavored rum." - brant cox, garrett snyder, nikko duren