I think that no explonations is the way to go here, but sometimes you might want to give some kind of explonation for whatever social reason. Something like "I used to drink every now and then, but the way it feels just didn't work for me".
Maybe you don't have to figure out the reason for aversion at all. Couldn't you just start choosing the option that feels less forced?
edit. I just broke my habit of NOT taking all the best candy from a candybag when being the first person to choose. :)