To make a sourdough starter, mix 1 cup of rye or whole wheat flour with 1 cup of water in a non-metal container, and remove 1/2 of the starter the following day. Feed and halve the starter each day until it readily doubles in size, smells acidic and appears bubbly.
When making a sourdough starter, use only non-chlorinated water, unbleached all-purpose flour and a non-reactive container, such as glass, to ensure the starter develops properly. 24 hours after beginning the starter, remove and discard 4 ounces of the mixture, and add an additional 4 ounces of flour and 4 ounces of water.
On the third day, stir the starter, and set aside 4 ounces of the mixture. Discard the remaining starter, and add an additional 4 ounces of flour and 4 ounces of water to the reserved starter. Continue to remove all except 4 ounces of the starter each day, and add an additional 4 ounces of flour and 4 ounces water to the reserved 4 ounces of starter for at least seven days.
Place the starter in a warm area of the home for optimum results. The starter is ready to use when it is bubbly in appearance, smells slightly acidic and doubles in volume within 12 hours after adding additional flour and water.