Split the 3 vanilla beans with a sharp paring knife. Add vanilla beans and alcohol to a clean bottle that has a sealable cap or canning jar with lid. Seal bottle or jar. Keep in a dark, cool place. Shake bottle a couple times a week so that the vanilla evenly extracts into the alcohol. Store for 2 to 3 months, the longer the better. Use extract to flavour cookies, cakes and other sweet confections. Makes 2 cups.