You can start with an inexpensive balsamic vinegar. Just cook it until it is reduced by half and has become thick enough to coat the pan. The rest is quite simple, producing a special vinegar that's thick, slightly creamy, and perfect for drizzling over ice cream or warm fruit.
Chocolate Balsamic Vinegar
Yields 16 fl. oz., or (4) 4 oz. gift bottles
For the balsamic vinegar (yields 1 cup)
2 cups balsamic vinegar
For the chocolate syrup (yields 1 cup)
1 cup water
1/2 cup sugar
2/3 cup Dutch process cocoa powder
1/4 teaspoon salt
1 teaspoon vanilla
For the balsamic vinegar
Reduce the vinegar by half (from 2 cups to 1 cup) over low heat. This will take approximately 20 minutes, stirring often. The vinegar will thicken and coat its pan. Set aside to cool once reduced. If you start with a better balsamic vinegar, you can skip this step and simply use 1 cup of balsamic straight from the bottle.
For the chocolate syrup
Dissolve sugar and salt into water. Bring to a boil in a small sauce pan. Reduce the heat to low and add cocoa, stirring until a syrup begins to thicken. Remove from heat and add vanilla. Set aside to cool.
Once completely cooled, mix the vinegar and chocolate syrup thoroughly and divide among four 4 oz. sterile glass bottles. I corked the bottles shut and hand-printed labels on adhesive strips to stick on over the top of each bottle for gift-giving.