Cordial: Kahlua

I was reminded today that my mom was the original cordial maker in the family, not me! She used to make Kahlua by jug, usually for my nana (her mom) periodically. I asked her today for the recipe and she told me it was originally from Jeff Smith, the Frugal Gourmet, and was shown on his show and written in one of his cookbooks:

4c sugar
4c water
2 oz instant coffee
1 vanilla bean
1 5th "of cheap bourbon"

Heat the sugar and water together, just below simmering. Add the instant coffee to create a coffee simple syrup. Get a gallon glass jug and add the bourbon and vanilla bean, then pour in the warm coffee syrup. Age at least one month. 
--Jeff Smith, "The Frugal Gourmet"

I haven't made this one yet, but it has proven excellence in my family.