INGREDIENTS
600 grams (about 1 pound) all-purpose flour, plus more as needed to feed the starter (see NOTES
600 grams (about 2 1/2 cups) water, plus more as needed to feed the starter (see NOTES)
RELATED RECIPES
Sourdough Bread (Due Pane)
DIRECTIONS
DAY 1: Into a 2-quart storage container, add 113 grams (4 ounces/scant 1 cup) of flour and 113 grams (4 fl ounces/1/2 cup) water. Stir together: This is your starter. Place the cover but do not seal. Set the container aside for 24 hours, out of the sun and off any cool surface. If the counters are cold, place the container on a wooden cutting board or a stack of towels.

DAY 2: Stir down the starter. Into a medium bowl, weigh 113 grams (4 ounces) of the starter, discarding the balance, known as discard, castoff or spent starter. Clean the storage container.

Into the starter, stir in 113 grams (4 ounces) of both flour and water. This is feeding. Scrape the fed starter back into the storage container. Place the cover on top, but do not seal. Set the container aside for 24 hours. Repeat on DAYS 3 and 4.

DAY 5 (Or when the starter is both actively bubbling and increasing in volume): The bubbles will begin to get larger and there will be strands of gluten evident when stirring the starter. Discard all but 113 grams and then feed with 113 grams of both flour and water. Scrape the fed starter back into the storage container and use a piece of tape to indicate its level in the container. In 12 hours, evaluate the starter. If it has doubled, feed the starter again (discard all but 113 grams and stir in 113 grams each flour and water.)

THE NEXT 2 OR 3 DAYS: Feed the starter every 12 hours until it begins to reliably double in 4 hours. Feed once or twice to reassure yourself that it is indeed doubling in 4 hours. Cover the starter tightly and refrigerate, or use the starter to bake bread or crackers, leaving 113 grams to continue to feed your starter.

Feed the starter once every week or when baking bread. If you're planning to bake bread and your starter has been ignored for more than 1 week, feed the starter first, letting it ferment on the counter for about 4 hours to confirm the leavening strength (doubled in size and topped with big, lazy bubbles).

If your starter has been ignored for more than a month it may take up to 4 feedings at 12 hour intervals to revive it.

TO FEED OR MAINTAIN YOUR STARTER: Stir down the active starter. Into a medium bowl, weigh 113 grams (4 ounces) of the active starter. Clean the storage container.

Into the starter, stir in 113 grams (4 ounces) of both flour and water until fully incorporated -- this is feeding. Scrape the fed starter back into the storage container. Place the cover on top, but do not seal. Set the container aside for 4 hours, at which point it should have doubled in size. When ready, the starter should be topped with large bubbles and have a strong wheat scent.