Sourdough Hydration Calculator & Percentage Guide
In sourdough baking, hydration is the single most defining variable determining your loaf's interior crumb structure, crust blistering, and dough extensibility. A dough with 68% hydration handles like modeling clay, while an 82% hydration dough feels like a living, jiggly pillow.
Yet, many beginner and intermediate bakers get confused when accounting for the water and flour already present inside the levain (sourdough starter). Below is the exact Baker's percentage math required to calculate true total hydration every single bake.
| Hydration Level | Dough Characteristics | Crumb Structure | Recommended Flour Type | Ease of Handling |
|---|---|---|---|---|
| 65% – 70% | Firm, stiff, holds shape easily | Uniform sandwich crumb, tight cell structure | All-Purpose or Standard Bread Flour (11.5% protein) | Beginner-friendly; easy shaping |
| 72% – 76% | Soft, supple, extensible | Classic open artisanal crumb with medium alveoli | High-protein Bread Flour (12.7%–13.5% protein) | Moderate; requires 3–4 stretch and folds |
| 78% – 85%+ | Very loose, glossy, sticky | Wild, custardy, translucent open crumb | Strong Hard Red Wheat, Manitoba, or High-Extraction flours | Advanced; requires coil folds and gentle pre-shaping |
The Baker's Percentage Rule
In professional baking, every ingredient weight is expressed as a percentage relative to the total flour weight (which is always 100%):
(375 ÷ 500) × 100 = 75% Hydration
How to Account for Starter (Levain) Hydration
Most standard sourdough starters are maintained at 100% hydration (equal parts flour and water by weight). To calculate the true total hydration of your dough, you must split your levain into half water and half flour:
- Suppose your recipe calls for 500g flour, 350g water, and 100g starter (at 100% hydration).
- The 100g starter contains 50g flour and 50g water.
- Total Flour: 500g + 50g = 550g.
- Total Water: 350g + 50g = 400g.
- True Hydration: (400 ÷ 550) × 100 = 72.7% True Hydration.
How Flour Absorption Limits Your Hydration
You cannot bake an 80% hydration loaf with standard low-protein all-purpose flour. Protein molecules (glutenin and gliadin) absorb water and create the structural web that traps carbon dioxide gases produced by wild yeast.
- Whole Wheat & Rye: Absorb 10% to 15% more water than white bread flour due to bran and pentosans, but produce a tighter crumb if not balanced with strong white flour.
- Autolyse Timing: For hydration above 75%, resting flour and water together for 45 to 60 minutes before adding salt and starter dramatically improves gluten extensibility.
Calculate sourdough hydration & stretch-fold intervals on iPhone
Custom Baker's percentage calculator with temperature-adjusted bulk fermentation timers and Live Activities.
Download Levain on App Store →Frequently Asked Questions
What is the best hydration for beginner sourdough bakers?
A hydration level between 68% and 72% is ideal for beginners. It provides enough moisture for good oven spring and a soft crumb, while remaining firm enough to shape without sticking to your hands or bench knife.
Why is my high-hydration sourdough dough so sticky and wet?
Sticky dough usually indicates that the flour's protein content cannot support that water volume, the gluten was not sufficiently developed through stretch-and-folds, or the dough was over-fermented during the bulk stage.
Does higher hydration mean bigger holes in sourdough?
Higher hydration facilitates a lighter, more open crumb, but giant irregular holes are primarily achieved through proper bulk fermentation timing and gentle dough handling rather than excess water alone.