Place all ingredients and 1/4 cup water in a heavy-bottomed pan. Cook over a low flame 2 to 3 hours, until the fruit is soft.
Remove the vanilla bean, and put the fruit through a food mill on the smallest setting. Pour into canning jars, filling them within a half inch of top. Tap filled jars on table, and run a knife around sides to remove air bubbles. Make sure the top of the jar is clean; seal.
Refrigerate immediately. The butter will keep for two to four weeks.