12 cup plain yogurt
12 cup milk (skim, regular or buttermilk)
12 cup unbleached flour
Mix the milk and yogurt together in a glass or pottery container (Do not use metal). Place lid on it, but don't seal it (sealed starters have been known to explode). Put mixture in a warm place (80 to 90 degrees) for about 24 hours. The yogurt and milk will separate forming a large curd, when adding the flour just stir it all back together. Add the flour stir, and put back in warm place for 3 to 5 days; stirring daily. It will bubble and have the odor of fermentation--it is ready to use. Remember the starter is a living thing and needs to be fed and fed frequently when an infant. I feed the "infant" weekly by placing it on the counter for several hours and allowing it to come to room temperature. Then remove 1/2 cup starter, discarding the remainder. Feed the 1/2 cup with equal amounts of milk (buttermilk will produce a stronger sour taste) and unbleached flour; i.e. 1 cup flour and 1 cup milk plus 1/2 cup of starter. If you would like, you can feed the starter with 1/3 cup dry milk powder and 2/3 cup bottled water in place of the 1 cup milk.