My original starter was 1 cup of milk warmed to 90-100 degrees, 3 tablespoons plain yogurt mixed in a jar and covered. Put it in a warm place for 24 hours (top of the water heater!) until thick like yogurt. Stir in 1 cup of flour till smooth. Let sit, lightly covered, for 2-5 days till bubbly and sour smelling. Keep in refrig., feeding with equal parts water and flour every few months, letting it sit on counter overnite till bubbly each time. If you feed it milk instead of water, it will be a stronger sour taste. Once I got it to the taste I liked, I stopped giving it milk and switched to water. I made it while camping in a tent one summer, kept it warm to get it started by putting the jar inside my sleeping bag!