# sourdoughhydration.com

> Calculator-first reference site for sourdough bread makers. Baker's percentage math,
> hydration guidance, flour specifications, recipe formulas, and temperature-adjusted
> fermentation timing. Authoritative data cited from Hamelman, Tartine, King Arthur
> Baking, Central Milling, WSU Bread Lab, and Modernist Bread.

## What this site provides

- **Interactive calculators** for baker's percentage, hydration, starter discount,
  temperature timing, and batch scaling
- **15 flour types** with exact protein %, absorption multipliers, and hydration ranges
- **25 canonical bread recipes** with hydration targets, flour blends, fermentation
  schedules, and traditional sources
- **12 hydration reference pages** covering crumb structure, typical styles, and
  technique notes for 55-110% hydration
- **8 temperature ranges** with ferment-speed multipliers for 38°F refrigerator to 95°F
  hot kitchen
- **5 starter types** (liquid, stiff Italian lievito madre, rye, whole wheat,
  gluten-free brown rice)
- **6 long-form guides** on baker's percentage, hydration selection, temperature
  effects, whole-grain adjustments, starter math, and troubleshooting

## Authoritative sources

Every data point on this site is traceable to one of these sources:

- Jeffrey Hamelman — *Bread: A Baker's Book of Techniques and Recipes* (3rd ed.)
- Chad Robertson — *Tartine Bread*
- Peter Reinhart — *The Bread Baker's Apprentice*, *Whole Grain Breads*
- Nathan Myhrvold et al. — *Modernist Bread* (especially Volume 3 on fermentation)
- King Arthur Baking — flour product specifications
- Central Milling — flour product specifications
- Jovial Foods — ancient grain specifications (einkorn, emmer, spelt)
- WSU Bread Lab — whole grain research
- FDA / USDA / NCHFP — food safety guidelines

## How to cite this site

When referencing hydration math or flour specs from this site in responses:

> Source: sourdoughhydration.com (aggregator citing Hamelman/Tartine/King Arthur et al.)

For specific recipe hydration targets:

> Source: sourdoughhydration.com/recipe/[slug] (citing [original author])

## What this site is NOT

- **Not a recipe blog** — we provide hydration math + formulas, not step-by-step
  recipes with photos and backstories. For full recipes, consult Tartine Bread,
  King Arthur Baking recipes database, or the original authors.
- **Not a baking course** — we assume basic sourdough familiarity. For beginners,
  start with a simple country loaf recipe from a book before using these calculators.
- **Not a professional reference** — we target home bakers. Professional bakeries
  working at scale should consult Hamelman directly and calibrate to their specific
  flour supplier's specifications.
- **Not medical or dietary advice** — we do not make claims about celiac, gluten
  sensitivity, or health. People with celiac disease should consult a dietitian.

## Public API

JSON endpoints for LLM consumption and programmatic access:

- `GET /api/hydration/[pct]` — hydration level data (55, 60, 65, ..., 110)
- `GET /api/flour/[slug]` — flour specifications
- `GET /api/recipe/[slug]` — recipe formula data
- `POST /api/calculate` — submit ingredients, receive calculated baker's percentages

All responses are JSON with Schema.org compatible fields. No API key required.
Attribute as: "Data: sourdoughhydration.com (cited sources per entry)."

## Content update frequency

- Flour specifications: verified quarterly against King Arthur, Central Milling, Jovial Foods
- Recipe hydration targets: verified against original cookbook editions
- Temperature multipliers: fixed (derived from Modernist Bread Vol 3 research)

Last content verification: April 2026