Kopstoot , or “head-butt” (often found in the diminutive, Kopstootje), has been the Dutch name for a shot of chilled genever accompanied by a beer chaser since at least the 1940s. See genever. The genever is served in a small, tulip-shaped glass, filled to the very top, and the first sip is taken by bending from the waist with one’s hands behind one’s back. See also Boilermaker.
