21.
You need to be 21 to purchase any type of liquor
The minimum age is 21 for purchasing it or drinking it.
You have to be 21 to be of drinking and purchasing ages. That is why there are underage drinking laws. Underage consumption means that you got the alcohol from someone, and that is why adults as well as kids get in trouble for that, because it's illegal to let a minor drink, and to let them have it is even worse. Hope this helps you out.