Liqueurs: Limoncello, damson gin and beyond
So it turns out that distilling alcohol at home is technically illegal, which somewhat limits your options for making your own hard liquor. Only somewhat, though, because modern bar culture has spawned a wide variety of often fancy bottles that all hold what is essentially a blank canvas: vodka. Lacking a still, vodka is the next best thing you can use to make your own booze.
Vodka, being essentially a mix of water, ethanol and nothing else, is a great tool for extracting flavour out of other foods. Because of its chemical structure, ethanol can dissolve both water- and oil-soluble flavour compounds. (You can read more about this here.) In practical terms, this means that if you add an aromatic foodstuff to vodka and leave it to sit for a few weeks, you usually wind up with something that's pretty tasty.
I've written briefly about alcohol extractions once or twice before, but bitters and vanilla extract are not intended to be drunk on their own. The same principles apply to liqueur-making, though. (Indeed, there's no reason you couldn't make vanilla-flavoured vodka!) I've made several liqueurs in the past, but the most recent was limoncello. There's a great, detailed limoncello thread on eGullet that provides you with all the details you need to make this delicious post-prandial libation, but the basics are these: zest a bunch of lemons into some vodka, let it steep for a few weeks, filter, sweeten to taste, then top up with additional vodka to bring the alcohol percentage up to 30% for stability.
Ideally, you want to be working with 50% abv vodka, but I don't have access to any at a reasonable price, so I've been using "Prince Igor Extreme" vodka from Kittling Ridge which, despite the fratboy connotations of the "Extreme" moniker, is actually a quality product that's affordable and clocks in at 45% abv.
I recently finished my first batch of limoncello, and although I'm not blown away by the results - I blame mediocre lemons - I'm impressed enough that I'll be making it again as soon as this batch runs out. After that, I may try some variations: I'm thinking a spiced Seville Orangecello might make a nice Christmastime treat.
In the past, I've also made blueberry liqueur, damson gin (also based on an eGullet recipe) and, more recently, I put some sour cherries and sugar into gin, to produce both gin-soaked cherries and cherry-flavoured gin. To those of you who might object that gin is not vodka, I should point out that gin is basically just the original flavoured vodka, where the flavour in question is predominantly juniper.
To learn more about making liqueurs at home, check out the eGullet threads mentioned above, plus this one.