What does hydration mean in bread dough, and how much water do I need?

Hydration is the weight of water as a percentage of the weight of flour, and it is the single number that predicts how a dough handles and what crumb it bakes into. What each band on the scale actually feels like.

Difficulty: intermediate
Time: 10 min
Read: 4 min

Short answer

Divide the water weight by the flour weight and multiply by 100. Around 60 per cent gives a firm easy dough; 65 per cent is the standard forgiving tin loaf; 70–75 per cent gives an open crumb and needs stretch-and-folds rather than kneading; above 80 per cent needs a banneton, strong flour and confidence.

Recipes that say 'add water until it feels right' are useless to someone who has never felt right dough. Hydration turns that into a number you can repeat, compare between recipes, and adjust deliberately. It is the reason two recipes with identical ingredients produce completely different bread, and the reason your dough behaved differently when you changed flour brands. The drawing puts four doughs from 55 to 85 per cent side by side with the crumb each produces underneath.

What you'll need

Digital scales that weigh water as well as flour

Bread dough hydration from 55 to 85 per cent and what each end produces

Step by step

Weigh the water rather than measuring it.One millilitre of water weighs one gram, so 325ml is 325g — which makes the arithmetic trivial once you are weighing everything. Baker's percentages are always by weight, never by volume.
Do the division.Water weight ÷ flour weight × 100. 500g flour with 325g water is 65 per cent. Everything else in a baker's percentage — salt, yeast, fat — is expressed against the flour weight the same way, which is why flour is always 100 per cent.
Place your recipe on the scale.55–60 per cent is bagel, pretzel and enriched-roll territory: firm, dry-surfaced, easy to handle, slow to rise. 65 per cent is the standard white tin loaf, kneadable by hand and forgiving. 70–75 per cent is open-crumb bread needing a scraper and folds. 80 per cent and above is a slack dough that will spread flat if the shaping is weak.
Adjust for the flour you have, not the number on the page.Absorbency varies between brands and dramatically between types. Wholemeal and rye need noticeably more water than white to reach the same feel, because the bran and the pentosans hold water that white flour does not. A 70 per cent wholemeal dough handles like a 62 per cent white one.
Hold a little water back and add it at the end.Mix at 90 per cent of the stated water, let it sit for ten minutes, then work the rest in if the dough feels tight. This is far easier than trying to add flour to a dough that is already too wet.
Change your handling, not just the number.A 75 per cent dough is not kneaded on a floured worktop — it is mixed in a bowl, rested, and given a series of stretch-and-folds every half hour. Trying to knead a wet dough conventionally is what makes people believe they cannot handle high hydration.

Tips

Write the percentage on every recipe you like. It is the fastest way to build a mental scale of what a dough should feel like.
Milk, egg and any other liquid count towards hydration; butter and oil do not, because fat does not hydrate flour.
A dough left to sit for twenty to thirty minutes after mixing — an autolyse — absorbs water it could not take up immediately, so a dough that felt too wet often firms up on its own.
Preferments, starters and poolish carry their own flour and water, and both have to be counted in the totals if you want the percentage to mean anything.

Common mistakes

Adding flour to fix a sticky dough — It lowers the hydration you deliberately chose and gives a drier, tighter loaf. Wet hands, a scraper and time are the answer.
Chasing high hydration for its own sake — An open, holey crumb is not better bread, it is different bread — and it is worse for sandwiches. Choose the hydration for what you want to eat.

If it doesn't work

Dough sticks to everything and spreads across the worktop

Cause: Higher hydration than your handling method suits, or the gluten is not yet developed. — Fix: Wet hands and a dough scraper instead of flour, and stretch-and-folds in the bowl. See `handle-sticky-dough`.

Dough is stiff, tears when stretched, bakes short and dense

Cause: Under-hydrated for the flour — very common when a white-flour recipe is made with wholemeal. — Fix: Add 5–10 per cent more water for wholemeal or rye and expect a softer dough.

Same recipe, different result after changing flour

Cause: Flours differ in protein and absorbency. The same percentage is not the same dough. — Fix: Adjust water to the feel you know, and record the new percentage for that flour.

High-hydration loaf spreads flat in the oven

Cause: Shaping tension, not hydration itself — wet dough needs more shaping strength, not less. — Fix: See `sourdough-loaf-flat-and-spread`.

Crumb is gummy despite a long bake

Cause: Very high hydration under-baked. Wet doughs need longer and a lower finishing temperature. — Fix: Bake to an internal temperature rather than a time. See `fix-gummy-bread`.

Questions people ask

Does hydration include the water in a sourdough starter?

It should. A starter at 100 per cent hydration is half flour and half water by weight, so 200g of starter adds 100g to the flour total and 100g to the water total. Recipes that ignore this understate the real hydration, sometimes by several percentage points.

What hydration should a beginner start at?

Around 65 per cent with strong white bread flour. It kneads on a lightly floured worktop, holds its shape, is hard to ruin, and gives a good tin loaf. Move up in five-point steps once that is reliable.