Source: Stuart Mennitt (firstname.lastname@example.org), r.c.b., 12/14/94
[what works better is to make the coffee Turkish style in a big sauce pan, bring it up to 190-200F, let it steep for a while, then strain it into a collander lined with cheesecloth and a giant paper filter, available at places that use those giant brew urns]
Immediately dissolve the sugar in the hot concentrate. Add the vodka and the reserved vanilla bean, and refrigerate in a sterilized , stoppered bottle for a few days. Taste: when you can begin to distinguish the vanilla flavor, discard the vanilla bean and store the liqueur in a second bottle, or pour and serve. If you're impatient, substitute vanilla extract for the bean. Add 2 or 3 drops per cup of vodka any time after you've brewed the coffee. If you want your liqueur to have the very heavy body of the commercial product, add the glycerine before refrigerating. Variations: Substitute light rum for the vodka, or add a dash of tequila to every cup of rum or vodka.
The simple addition of chocolate turns coffee liqueur into Mocha Liqueur. Thoroughly mix one part hot water and one part unsweetened cocoa powder. Add 1/2 tablespoon of this mixture to every cup of the finished coffee liqueur, and mix thoroughly.
 Styles of coffee liqueurs differ. Before making your own, I suggest you determine which style you prefer: Kahlua, for example, is heavy-bodied and based on a dark-roast coffee; others, like Tia Maria or liqueurs based on Kona coffee, use a lighter roast. If you prefer Kahlua, use a dark-roasted coffee and go a little heavier on the vanilla and (if you use it) glycerin; if you prefer one of the liqueurs based on a lighter roast, use a medium-roast, acidy coffee, like a Costa Rican