1. Assess Your Starter’s Current State: Before feeding, check for bubbles and a pleasant yeasty, slightly sour smell. If flat or smelling strongly of acetone, it needs feeding.

2. Prepare for the Feed: Gather a clean jar, your active starter, flour, and water. A kitchen scale is recommended for precise measurements.

3. Discard Most of the Starter: Scoop out all but about 1-2 tablespoons (20-30 grams) of your active starter. Discard the excess or use it in discard recipes.

4. Add Fresh Water: To the remaining starter, add an equal weight of room temperature filtered water (e.g., 20 grams water to 20 grams starter). Stir well until dissolved and no lumps remain.

5. Incorporate the Flour: Add an equal weight of flour (e.g., 20 grams flour) to the mixture. Mix thoroughly until all flour is incorporated and there are no dry spots. The mixture should be thick but stirrable.

6. Scrape Down the Sides and Mark the Level: Use a spatula to scrape down any flour or starter clinging to the sides of the jar. Mark the current level with a rubber band or dry-erase marker to track its rise.

7. Cover Loosely and Let It Rest: Place a lid loosely on the jar or cover with plastic wrap or a clean kitchen towel. Do not seal tightly. Leave at room temperature (ideally 70-75 F or 21-24 C) for 4-12 hours until bubbly and doubled in size.