Mix together in a glass or plastic bowl the above ingredients. Do not use metal utensils. Cover the bowl with a tight fitting lid and allow to sit in a warm, draft-free location for 4 to 7 days, gently stirring once a day.
You may use your starter after 4 days.
To use your starter, simply remove the amount called for in the recipe and add to the other ingredients. Replace the amount removed with equal amounts of water/milk and bread/unbleached all purpose flour.
After feeding your starter, leave on counter for 24 hours. At the end of that period you may refrigerate your starter. You must refeed at least once every 7 days. If you do not plan to use it, then take one cup out and throw away and feed.
If you will be away on vacation you may freeze your starter, thaw it in the refrigerator upon your return. As soon as it is thawed, remove at least one cup and feed as above.
Alternate feedings, one week with milk, the next with water.