Source: gizmodo

Technique 1: So Fresh and So Clean Clean

Generally speaking, Granny Smith apples are the tartest apples you can find year-round (thanks, South America!). Grab four large grannies and a 750ml bottle of the bourbon of your choice (we went with Woodford Reserve). Chop the apples up into small cubes, which increases the total surface area and speeds the process up, then toss them into a large glass jar. A two quart jar should do nicely if you’re just doing one bottle’s worth at a time. Pour in the whiskey, seal the lid, and let it rest.

If you’ve ever bobbed for apples you’ll recall that they’re pretty buoyant, which isn’t ideal for keeping them submerged in alcohol. There are a couple of fixes, though. You can put a wide weight (like a small plate) on top of the apples in the jar to help keep them pushed down. Or you can just give the jar a little shake a few times a day to make sure the apples on top get rotated down.

How long you leave the apples varies depending on the type you use and your personal preference. I would suggest five days at a minimum, especially if you’re working with something as tart as a Granny Smith. That said, some suggest leaving the apples in for as much as six weeks. We recommend you start tasting after a few days; when it gets to a place you like, strain the liquid through a paper coffee filter, which will restore the whiskey’s clarity.

Technique 2: Sweet n’ Dry

Tim Laird over at Bourbon Buzz suggests using dried apple slices. Just crazy enough to work! One of the advantages of this technique is that you don’t need a big jar—you can just stuff the dried apple slices into the bourbon bottle—which actually looks really cool. Laird suggests using one liter of Woodford Reserve and five ounces of dried apple slices (I had a 750ml bottle, so I scaled the apple slices back to 3.75 ounces). I poured out a few ounces of the whiskey (into a glass; waste not, want not), stuffed the dried apple slices in, poured a little whiskey back in to cover, and corked it.

There are some pros and cons to this technique. On the positive side, it’s faster, taking just three days to mature. This is due to the concentrated flavors and the more porous nature of the dried apples. You also aren’t diluting the whiskey at all, because there’s virtually no juice to leak out of dried apples. And again, it just looks really cool.

On the con side, the resulting taste is a little more like dried apples than fresh apples. Use dried granny smiths if you can find them, which will help cut the sweetness a little. Also, you’re going to lose some volume because dried apples are like little strips of sponge—they’re going to absorb some of your precious nectar.