Beer milkshake

From Tongue Tied

A beer milkshake is a special type of milkshake invented by Dave Lister. In basics it is a milkshake that tastes like beer, it is never revealed how (it is probably just a milkshake with beer poured on it). It is not known whether or not it is a truly alcoholic beverage. Lister has taught at least one of the Red Dwarf vending machines how to create it. It is mentioned several times in Series I. Confidence listed it as one of Lister's greatest inventions with the quote "another great idea from the man who invented beer milkshakes!"