Sourdough hydration math, solved.
Exact flour, water, salt, and starter weights for any hydration, any flour, any style. Starter discount applied automatically. Temperature-adjusted fermentation timing cited from Modernist Bread.
- Flour to add
- 450 g
- Water to add
- 325 g
- Salt
- 10 g
- Levain @ 100%
- 100 g
- Total dough
- 885 g
- Effective hydration
- 75%
How the math works
Total water = flour × hydration %. Your levain contributes 50 g flour + 50 g water — both count toward the totals. You add only the remainder as fresh flour and water.
Salt % is computed on total flour weight, not final-dough flour.
What hydration should I use?
Browse all 12 levels →Sourdough hydration runs from 55% (bagels, pretzels) to 95%+ (Pan de Cristal, expert-only). The sweet spot for artisan hearth loaves is 72–78%. Lower means tighter crumb and easier handling; higher means more open crumb but demands more technique.
- 55–65%Tight crumb
- 65–75%Balanced
- 75–85%Open crumb
- 85%+Extreme
Popular recipes
Hydration targets cited from Hamelman, Robertson, AVPN, and King Arthur Baking.
Find a recipe by flour
Absorption multipliers from King Arthur, Central Milling, Jovial, Caputo.
Temperature changes everything
Your 4-hour bulk at 76°F becomes 6 hours at 68°F — and under 3 hours at 82°F. Multipliers from Myhrvold, Modernist Bread vol 3.