Wikipedia Article About Tuaca on Wikipedia
Tuaca is a brand of Italian liqueur. It is sweet and viscous, and its ingredients include vanilla (which gives it its predominant flavor) and citrus. The recipe supposedly dates to the Renaissance; one story is that the liqueur was created for Lorenzo the Magnificent. Tuaca is produced by the Tuoni family in Livorno, Tuscany.
Tuaca's strength is 70 proof.
It is commonly mixed with red bull in a shot glass that contains two bulb shapes. The bottom section contains the red bull and the shot of tuaca floats in the top bulb due to its density. The whole lot is then taken in one shot.