Hydration, explained plainly

Hydration is the baker’s word for how wet a dough is. It is not a feeling and it is not a cup measure. It is the weight of all the water divided by the weight of all the flour, written as a percentage.

Take a simple dough: 1,000 g of flour, 650 g of water, 20 g of salt. Hydration is 650 ÷ 1,000 = 65%. The salt is not part of that sum. Salt is its own line, here 2%. At 65% the dough feels like a soft earlobe once the flour has had time to drink. It kneads without sticking much, holds a shape, and suits a sandwich loaf or a beginner’s boule.

At 75%, as in the classic boule, the dough slumps more and traps larger holes if the fermentation and the folds are right. At 80% and above it clings to the hands. Bakers stop adding flour to fix that. They wet their hands, fold the dough, and give it time. Extra flour would lower the hydration and make the crumb tighter, which is a different bread, not a rescued one.

The number is only honest if every flour and every water is in it. A levain of 100 g at 100% hydration is 50 g flour and 50 g water. Leave those out and a dough that is really 75% will be written down as something drier, and it will not match next time. This is the mistake the formula on each recipe, and the calculator, are built to prevent. Mark a starter as a starter and type the flour and water inside it. The percentage does the rest.

Whole-grain flour drinks more than white flour, and a humid day wets the sack before you do. Two doughs at “75%” can feel different. Trust the percentage as the record, and trust your hands for the last spoon of water. Write down what you actually poured. That note is the recipe you will be glad to have in a month.