Step 1

Step 1: Prepare Your ToolsGet a clean glass jar, a digital kitchen scale, a spoon or spatula, and your ingredients: sourdough starter, flour, and water.

Step 2

Step 2: Weigh Your StarterPlace your jar on the scale and tare it (zero it out). Then add 50 grams of your active starter to the jar.

Step 3

Step 3: Add FlourAdd 50 grams of unbleached all-purpose or bread flour to the starter.

Step 4

Step 4: Add WaterNow pour in 50 grams of room temperature filtered water. If using tap water, let it sit overnight first to let the chlorine evaporate.

Step 5

Step 5: Mix ThoroughlyUse a spatula or spoon to stir everything together until fully combined. The texture should be like thick pancake batter with no dry flour left.

Step 6

Step 6: Mark the LevelPlace a rubber band around the jar or use a marker to note the starting level of your starter. This helps you track its rise.

Step 7

Step 7: Cover LooselyCover the jar with a loose lid, cloth, or plastic wrap. It needs airflow — avoid sealing it tightly.

Step 8

Step 8: Let It RestLeave the jar at room temperature (ideally 70–75°F). Allow it to rest undisturbed for 6 to 18 hours, depending on the temperature.

Step 9

Step 9: Check for ReadinessThe starter is ready when it has doubled in size, is full of bubbles, and has a light, sponge-like texture. It should smell mildly tangy and fresh.

Step 10

Step 10: Use or StoreUse your active starter in a recipe, or store it in the fridge if you’re not baking. If refrigerating, feed it first and allow it to sit at room temperature for a few hours before chilling.