The all-in-one Sourdough| Calculator

Baker's percentage (also called baker's math) expresses each ingredient as a percentage of total flour weight. Flour is always 100%. To calculate: divide the ingredient weight by the flour weight and multiply by 100. For example, 1000g flour and 650g water gives 65% hydration. This system makes it easy to scale any recipe up or down while keeping ratios perfectly consistent.

Divide total water by total flour and multiply by 100 — but the key is to include the water and flour inside your sourdough starter. A 100% hydration starter at 200g contains 100g flour and 100g water. So for 800g flour, 200g starter, and 550g added water: total flour = 900g, total water = 650g, hydration = 72%. Forgetting the starter's contribution is the most common calculation mistake.

At room temperature (20–25°C), feed every 12–24 hours. In the refrigerator, once a week is enough. The standard ratio is 1:1:1 (starter:flour:water by weight). Signs your starter needs feeding: it has collapsed, smells strongly of acetone or alcohol, or has a layer of liquid (hooch) on top. After feeding, it should double in size within 4–8 hours at room temperature.

A preferment is a portion of dough mixed and fermented before the final mix to develop complex flavor and improve texture. The main types: Poolish (100% hydration, equal flour and water, small amount of yeast — adds mild sweetness and open crumb), Biga (50–60% hydration, drier and stiffer — adds nutty flavor and chewy texture), and Levain/Sourdough Starter (wild yeast, no commercial yeast — adds tang and depth). Each works best with different bread styles.

Three steps: 1) Add up all flour in the recipe — that's your 100% base. 2) Divide each other ingredient's weight by the total flour weight. 3) Multiply by 100. Example: 1000g flour, 700g water, 20g salt, 200g starter = 100% flour, 70% water, 2% salt, 20% starter. Once in percentages, you can scale to any batch size by choosing a new flour weight and multiplying.

It depends on the style and your experience. Neapolitan: 60–65% (easy to shape, classic chewy crust). New York: 62–68% (slightly more open crumb). Roman/al taglio: 70–80% (light, airy, harder to handle). Start at the lower end of each range and increase as your shaping skills improve. Higher hydration dough needs gentler handling, longer fermentation, and well-floured surfaces.

DDT is the target temperature of your dough right after mixing, usually 24–26°C (75–78°F) for most bread. Temperature controls fermentation speed — even 2°C difference can change your timeline by hours. The formula: Water Temp = (DDT × 3) − Room Temp − Flour Temp − Friction Factor. The friction factor (usually 20–40 for stand mixers, 0–6 for hand mixing) accounts for heat generated during kneading.

With baker's percentages, scaling is straightforward: pick your target flour weight and multiply each percentage by it. For example, at 70% hydration and 2% salt: 500g flour → 350g water + 10g salt, or 1500g flour → 1050g water + 30g salt. The ratios stay identical regardless of batch size. For very large batches, slightly reduce yeast to keep fermentation manageable.