Eierlikör

Eierlikör descends from Advocaat, a Dutch egg liqueur whose own roots trace to a Brazilian drink called abacate, made by indigenous peoples with avocado, sugar and spirit and carried back to Europe by Dutch colonists in the 17th century. Avocados being scarce and costly in Europe, makers replaced the rich fruit with egg yolks, arriving at the thick yellow liqueur known today. The commercial German product is bound up with the firm Verpoorten, founded in 1876 in Heinsberg by Eugen Verpoorten, which industrialised egg liqueur and remains by far the dominant German producer. German law sets a minimum egg-yolk content for anything sold as Eierlikör, which is what gives the genuine article its body.

Opaque and glossy, the colour of thick vanilla custard, pouring slow and coating the glass. It is sweet and unmistakably eggy, rich with yolk and sugar, the alcohol warm but tucked under the creaminess, with vanilla running through. Sipped neat from a small stemmed glass it drinks like a dessert; spooned warm over vanilla ice cream it half-melts into sauce. The texture is the whole point — pourable but viscous, somewhere between a liqueur and a custard.

The drink is an emulsion held together by egg yolk. Yolks are beaten with sugar until pale and thick, which both dissolves the sugar and starts the foam; spirit, and usually cream and vanilla, are then blended in. The lecithin in the yolk is the emulsifier that keeps the fat, water and alcohol bound into one smooth, stable liquid rather than separating. Homemade versions are sometimes warmed very gently over a water bath to thicken the yolks toward a custard, but the heat must stay low — too hot and the yolks scramble, breaking the emulsion. The alcohol also acts as a preservative, letting the egg-rich liqueur keep far longer than a fresh custard would.