My best friend and I had some out-of-this-world margaritas a few months ago at National Mechanics in Philadelphia made with jalapeno-infused tequila. I thought making him some would make a fun Christmas gift (and party?). Plus, it's so easy it should be illegal. You can use any tequila you want as long as it's 100% agave. I personally prefer silver, but that's just personal preference. For this batch, I opted for 1800 since it's a gift and the bottle caught my eye. Also, it's delicious. NOTE: While you should use quality tequila for this, please don't spring for a bottle of Patron. Sauza works just fine. —ixshelle
Cut the stems off the peppers and slice them lengthwise. scoop out all of the seeds and slice into strips.
Open your tequila and drop in the jalapeno strips. You may need to pour a little of the tequila out if the peppers displace more room than the bottle allows. If so, take a jigger--you deserve it. No, I'm kidding. No drinking until your capsaicin-infected gloves are in the trash and you wash your hands. Go on now.
Now you wait. However long you want, really. Taste every 24 hours or so until you reach the desired amount of spiciness. After it's hot to your liking, strain the tequila into the pitcher and funnel it back into the bottle and toss the peppers. This method can also be done with fruits and herbs, and it'll last just as long as un-infused liquor.