Mix equal parts flour and water in a clean jar
Use 50 g flour and 50 g water to start
Stir until no dry flour remains
Cover loosely with a lid or cloth
Leave at room temperature for 24 hours
Discard half of the mixture
Feed with equal parts flour and water again
Repeat discarding and feeding once every 24 hours
Keep the starter in a warm place
Use unbleached all-purpose or whole wheat flour
Continue feeding for 5 to 7 days
Look for bubbles and a sour smell
The starter is ready when it doubles in size within 4 to 8 hours after feeding
Store in the refrigerator once active
Feed weekly if refrigerated
Use clean utensils and a clean jar