When Matt and I first moved to the Boston area, we spent a lot of time at Temple Bar drinking their barrel aged negronis. They simply mixed up a large batch of negronis – equal parts gin, sweet vermouth, and Campari – and aged them for 3 months in whiskey barrels. When Matt’s birthday rolled around, I found smaller barrels on Barrels Online that can be used for aging cocktails. It was the perfect gift! They even personalize them, so I got his initials engraved on the front.
Negronis are traditionally served with an orange peel that is put under a flame and squeezed into the drink, but we were too much in a hurry to finally try the final product to even remember that.
Here are a few links to articles/websites on barrel aged cocktails that we used when trying to figure out how to use our barrel. It has become quite a trend, apparently.