Baker's percentages, finally explained to myself
For two years I followed recipes by weight and could not work out why I was unable to adapt any of them. Then someone explained baker's percentages in about ninety seconds and a large amount of confusion went away at once.
The rule: flour is 100%, always. Every other ingredient is expressed as a percentage of the flour weight, not of the total. So a dough with 1000 g flour and 750 g water is at 75% hydration, and it stays 75% hydration whether you make one loaf or nine.
The numbers worth memorising
- Hydration 60–65%: stiff, easy to shape, tight crumb. Bagels, sandwich tins.
- Hydration 70–75%: the useful middle. Most sourdough lives here.
- Hydration 80%+: wet, slack, open crumb, hard to handle. Focaccia, ciabatta.
- Salt 2%: essentially always. Below 1.8% tastes flat, above 2.4% slows fermentation noticeably.
- Starter 15–25%: lower for a long cool rise, higher when you are in a hurry.
The practical payoff is scaling. My tin takes 900 g of dough. At 75% hydration with 20% starter and 2% salt, the total comes to 197% of the flour weight. So flour is 900 ÷ 1.97, which is 457 g, and from there water is 343 g, starter 91 g, salt 9 g. Thirty seconds with a calculator and no recipe required.
It also makes two recipes comparable at a glance. Two loaves that look completely different on paper often turn out to be the same dough at different hydration, and once you can see that you stop collecting recipes and start adjusting one.
Rye is the exception, as rye always is. Percentages still work arithmetically, but rye absorbs water differently and a 75% rye dough behaves nothing like a 75% wheat dough. You have to learn that one by feel.