Sourdough hydration explained

Sourdough hydration is the weight of water in a dough expressed as a percentage of the flour weight. If a loaf uses 500 g flour and 375 g water, that is 75% hydration. Higher numbers mean a wetter, slacker dough; lower numbers mean a stiffer one. The figure is a baker’s shorthand for how the dough will feel and how the crumb tends to open.

How to calculate it

The formula is simple: water weight divided by flour weight, times 100.

• 500 g flour, 350 g water = 70%
• 500 g flour, 400 g water = 80%

Count every source of flour and water, including the flour and water already in your starter. If you add 100 g of starter at 100% hydration, that brings 50 g of flour and 50 g of water to the total. Skip that step and your real hydration runs higher than the number on paper. To check a recipe or work backward to a target, use the hydration calculator.

Typical ranges

Most home loaves land between 65% and 85%. Where you sit depends on the flour, the result you want, and how much wet dough you are willing to handle.

Hydration	Feel	Typical use
60-65%	Stiff, easy to shape	Bagels, sandwich loaves, beginners
68-75%	Supple, holds shape	Everyday country loaf
78-85%	Slack, sticky	Open ciabatta-style crumb
85%+	Pourable, hard to handle	Focaccia, experienced bakers

These are starting points, not rules. A strong bread flour can carry more water than a weaker all-purpose flour at the same number, and whole grain flours drink more, so a 75% whole wheat dough feels drier than a 75% white one.

What hydration does to the crumb

Water gives the crumb room to expand. A wetter dough traps gas in larger, more irregular holes, the kind you see in a rustic open loaf. A drier dough sets up a tighter, more even crumb that slices cleanly and holds a filling without tearing. Crust changes too. Higher hydration tends to blister and crackle more, while lower hydration bakes to a thinner, smoother shell.

It is not the only factor. Fermentation time, shaping, and oven heat all shift the result. But if your crumb is dense and you want it more open, adding water is usually the first lever to pull.

What it does to handling

This is where the trade-off bites. Wet dough is harder to shape, sticks to everything, and spreads if your gluten or your technique is not up to it. That is the real reason to move up slowly rather than jumping to 85% on your second bake.

A few habits make high hydration manageable:

1. Build strength with stretch and folds during bulk instead of early kneading.
2. Wet your hands rather than flouring the bench, which keeps the dough from drying and tearing.
3. Give it a longer rest after mixing so the flour fully absorbs the water before you shape.

If you are new to this, start around 70%, get comfortable, then add 2-3% at a time. You will feel the difference long before you see it in the crumb.

A realistic starting point

For a first proper sourdough, 72% to 75% is a forgiving target with most bread flours. It shapes without fighting you and still bakes up with a decent, open crumb. Once a dough at that level feels routine, push higher. The numbers here are estimates, so judge the dough by how it behaves in your hands and adjust from there. Getting your culture strong first helps, so it is worth dialing in feeding your starter before you chase a wetter loaf.