Dough Hydration Calculator

In short Hydration is water divided by flour, expressed as a percentage — so 700 g of water on 1000 g of flour is 70%. The complication, and the reason most hydration calculators quietly give the wrong answer, is the levain. A sourdough starter, poolish or biga is itself flour and water, so a loaf built on one has two hydration figures that are not the same number. DOUGH hydration is the water you pour over the flour you weigh out. TOTAL hydration counts the levain's flour and water as well, and it is what the crumb actually experiences. A 200 g levain at 100% hydration is 100 g of flour and 100 g of water, and both belong in the sum. The two figures agree in exactly one case: when the levain sits at precisely the same hydration as the dough. Any other levain moves the total — a wetter one pulls it up, a stiffer one pulls it down — and this page works out which, rather than assuming. Which figure should you quote? Total hydration if you are describing the loaf to another baker, because that is what the dough really is. Dough hydration if you are telling someone what to put in the bowl. Both are correct and they answer different questions, and confusing them is why a recipe at "80% hydration" sometimes feels nothing like the last one you made.