4 cups water
1 2/3 cups dry milk

Heat water in top of double boiler. Dissolve milk in water. Continue heating at 180°F for 1 minute. (If no double boiler, use low heat setting.) Place pan with milk mixture in cool water until temperature reaches 115-120°F. Take starter from refrigerator. (I use 2 tablespoons of Dannon's as my original starter.)

Mix about 2 tablespoons of warm mixture into starter. Pour into rest of mixture and stir well. Pour into tall baby food jars, making sure to put 2 tablespoons of mixture in one jar to save for starter. Fill a quart jar with hot water, and place it in center of Styrofoam or chest cooler. Place jars of mixture around jar of water. Cover cooler, and leave undisturbed for 4-5 hours. Refrigerate. To add flavors, stir in fruit or preserves before serving.