Day 1: In a glass jar, mix 1 cup of whole wheat flour and 1 cup of water. Stir well, cover with a cloth, and let it sit at room temperature for 24 hours.
Day 2: Discard half of the starter. Add 1 cup of all-purpose flour and 1 cup of water to the remaining starter. Stir well, cover, and let it sit for another 24 hours.
Day 3-5: Repeat the process of discarding half and feeding the starter with 1 cup of flour and 1 cup of water every 24 hours. By day 5, the starter should be bubbly and ready to use.
Notes:
Keep the starter in a warm place for best results. If your kitchen is cold, it may take longer to develop.