Gelatin is a food thickener and gelling agent that has been used in savory and sweet dishes for centuries. Many people are familiar with molded fruit desserts and jiggly cutouts -- and almost no liquid is off-limits to the amazing gelling property of gelatin. Alcohol does somewhat inhibit the gelling factor of gelatin, however, and if you are trying to thicken something with alcohol there are a few rules to abide by.
Set It Up
Gelatin can gel liquids that contain up to 40 percent alcohol with no adverse effects and no ratio modifications. To make sure the percentage will work, do some simple math. If an alcohol is 120 proof it's 60 percent alcohol. That means one cup of liquor mixed with one cup of juice will be 30 percent alcohol and will set perfectly well for your sweet treats. As a standard rule of thumb, one packet of gelatin contains about 2 1/2 teaspoons and is enough to gel two cups of liquid. Decrease liquid for a firmer set, or increase if you'd like a softer gel.