Step 1 / 10

warm, 24-26°C, covered

20 g mature starter + 40 g of the flour + 40 g of the water = levain. Use it when it has domed, smells of yogurt rather than vinegar, and a spoonful floats — the float is trapped gas, the only honest proof the culture is at peak. Past peak the sugars are spent, the pH has dropped, and bacterial proteases start cutting the gluten you have not built yet