Two bread recipes can use identical ingredients and produce completely different loaves. The variable responsible is almost always hydration, the ratio of water to flour, and it is the single most useful thing to understand about bread.

What Hydration Describes

Hydration is expressed as a percentage of the flour weight. A dough with a kilogram of flour and seven hundred grams of water is seventy per cent hydration.

It is not a measure of how wet the dough feels, though the two correlate. It is a precise ratio, which is why it only means anything when both are weighed. Kitchen scales reading in grams, such as those in the Escali range, make the figure available; measuring by volume makes it a guess.

What Changes as Hydration Rises

• Around 60%: stiff dough, easy to handle, tight even crumb, sandwich bread
• Around 65 to 70%: standard artisan territory, manageable, open-ish crumb
• Around 75 to 80%: sticky, requires technique, irregular open crumb
• Above 80%: very difficult to shape, dramatic holes, ciabatta and similar
• Around 50 to 55%: bagels and pretzels, dense and chewy by design

Why Higher Is Not Better

High-hydration bread photographs well and has acquired a certain status, which has led a great many home bakers to attempt seventy-eight per cent doughs before they can handle sixty-eight.

Wet dough is genuinely difficult. It spreads rather than holding shape, sticks to everything, and requires shaping techniques that take practice. A well-made loaf at sixty-five per cent is far better than a flat, dense one at eighty.

Working up gradually, adding two or three per cent at a time once a dough is consistently good, is the sensible progression.

Flour Changes the Answer

Different flours absorb different amounts of water, which is why the same percentage behaves differently between recipes.

Strong bread flour with high protein absorbs more than plain flour. Wholemeal absorbs considerably more, since the bran takes up water, and a wholemeal dough at seventy per cent feels far stiffer than a white one at the same figure. Rye is different again.

This is why recipes specify the flour type, and why substituting without adjusting the water produces unexpected results.

Environmental Factors

Humidity affects flour, which absorbs moisture from the air. Flour stored in a damp kitchen contains water that is not in the recipe, and a dough made from it will be wetter than the numbers suggest.

This is a genuine effect and a small one. It explains why the same recipe can feel slightly different in summer and winter, and why experienced bakers hold back a little water and add it after assessing the dough.

Adjusting Sensibly

Change one variable at a time and record what you did. A notebook with flour weight, water weight, hydration percentage and a note on the result is worth more than any recipe collection, because it describes what works in your kitchen with your flour.

Without weighing, none of that is possible, which is the practical argument for the scale rather than any theoretical one.