About SourdoughHydration
SourdoughHydration is a calculator-first reference for home sourdough bakers. The math is the product: baker's percentage for any hydration, any flour, any recipe style, at any kitchen temperature. Starter discount applied automatically.
Every data point on this site traces back to a named source — Jeffrey Hamelman (Bread, 3rd ed.), Chad Robertson (Tartine Bread), Peter Reinhart (The Bread Baker's Apprentice), Nathan Myhrvold et al. (Modernist Bread vol 3 on fermentation), and publisher spec sheets from King Arthur Baking, Central Milling, Jovial Foods, and Mulino Caputo.
No AI-generated recipes. No user reviews or ratings. No newsletter capture. The site is free to use and funded by display ads plus a small, clearly-marked set of Amazon links to the baking gear the calculator assumes (a gram scale, a Dutch oven). See how this is funded below.
How this site is funded
SourdoughHydration is free. Running it (hosting, the database behind every flour and recipe page, the time keeping figures cited and current) is paid for two ways: display ads, and a short list of Amazon links to the gear the math depends on.
As an Amazon Associate, SourdoughHydration earns from qualifying purchases — at no extra cost to you. We only point to categories the calculator actually relies on: a 0.1 g scale (baker's percentage is by weight), a Dutch oven for steam, a banneton, a lame, high-protein bread flour. We don't accept payment to feature a specific brand, and gear links never appear inside the calculator or a recipe's formula — only in a clearly-labelled section below it. Affiliate links carry rel="sponsored"per Google's guidelines.
Data update policy
- Flour specifications: verified quarterly against publisher data sheets.
- Recipe hydration targets: verified against original cookbook editions.
- Temperature multipliers: fixed (derived from Modernist Bread vol 3 research — constants, not observational).
- Source URLs on every data-backed page; last-verified date in the page footer.
What this site is not
- Not a recipe blog — we provide math + formulas, not photo-led recipes.
- Not a baking course — we assume basic sourdough familiarity.
- Not a professional reference — for scaling to commercial production, consult Hamelman directly and your specific flour supplier.
- Not medical or dietary advice — consult a dietitian for celiac or gluten-sensitivity questions.
Who runs this
SourdoughHydration is operated by Paulo de Vries from the Netherlands. The site follows EU privacy law (GDPR) by default — see the privacy policy for data-processing details and your rights.