I think like 16/17...my friend's mom would let us have wine. She was from Spain and thought the 21 drinking age threshold in the US was ridiculous.
I don't think I tried any hard liquor until I was 18. After gradfest, to be exact.
Edit: I just remembered the time I drank some of my stepdad's open beer when I was 6.
He had one of those stay cool can sleeves over it and I thought it was a soda.