What does 78% hydration mean in sourdough?

78% hydration means the dough contains 78 grams of water for every 100 grams of flour, by weight. It is a baker's-percentage convention: flour is always 100%, and other ingredients are expressed as a percentage of the total flour weight.

Which sourdough styles use 78% hydration?

Miche, Rye 40 Percent. See each style's page for the full recipe formula.

How do I convert 78% hydration into grams of water?

Multiply total flour weight by 0.78. For example, 500g flour × 0.78 = 390g water. Use the calculator below to handle salt, levain, and starter-discount math automatically.

Hydration reference · intermediate

Sourdough at78% hydration

Noticeably open, shiny crumb. Irregular medium-to-large holes. Glossy cell walls. Moist texture.

Typical styles: Miche · Rye 40 Percent

What does 78% hydration look like?

Noticeably open, shiny crumb. Irregular medium-to-large holes. Glossy cell walls. Moist texture.

Technique for 78% dough

Upper range of 'standard' hearth hydration. Benefits from high-extraction flour which tolerates the hydration. Use coil folds instead of stretch-and-folds to build structure without deflating. Cold retard mandatory.

Try the calculator at 78% hydration

Adjust the target hydration, salt, and levain below. All outputs update as you type, with starter discount applied.

Total flour(g)

Target hydration(%)

Salt(%)

Levain of flour(%)

Levain hydration(%)

Flour to add: 450 g
Water to add: 340 g
Salt: 10 g
Levain @ 100%: 100 g
Total dough: 900 g
Effective hydration: 78%

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.

Open 80% hydration guide →

Popular recipes at 78% hydration

How to convert 78% to grams of water

Multiply total flour weight by 0.78. For a 500g flour dough at 78% hydration, that is 390 g of water.

Remember that the levain contributes some of the flour and water. The calculator above subtracts the levain's contribution automatically so the numbers you weigh on the counter are the real ones.