Sourdough Bulk Fermentation: Mixing the Dough and Reading the Rise
Mixing, autolyse, a few folds, and then the long wait while the culture works through the dough. This is where the bread is made, and the only variables that matter are time and temperature.
ON THIS PAGE · 6 SECTIONS
Bulk fermentation is the first rise of sourdough dough, done as a single mass before shaping. At 22°C it takes around five hours after mixing; every 6°C warmer roughly halves that, and every 6°C cooler roughly doubles it. The dough is ready to shape when it has grown by half to three-quarters, feels airy and domed, and a wet finger pressed into it springs back slowly. Judge the dough, not the clock.
The formula
One loaf. Everything is weighed — a cup of flour can vary by 30% depending on how it was scooped, and this is a process that punishes that.
| Ingredient | Weight | Baker's % | Notes |
|---|---|---|---|
| White bread flour | 500 g | 100% | Strong white, 12–13% protein. Not wholemeal — the bran is where the phytate lives. |
| Water | 375 g | 75% | Filtered. Warm (about 28°C) in a cold kitchen, room temperature otherwise. |
| Ripe starter | 100 g | 20% | Fed 1:5:5 the night before, used at its peak. |
| Sea salt | 10 g | 2% | Added after the autolyse, not before. |
Mixing and the autolyse
Mix the flour and water only, by hand, until there is no dry flour left. Cover and leave it for an hour. This is the autolyse: the flour hydrates fully and the gluten begins forming on its own, without any kneading, which is why sourdough needs so little handling later.
After the hour, add the starter and the salt. Squeeze and fold the dough in the bowl for two or three minutes until both have disappeared into it. It will feel shaggy and slightly tacky. That is correct.
The whole day, re-timed to your kitchen
Move the slider to your kitchen's temperature. Everything before the fridge scales; the fridge, the bake and the cooling do not. A schedule copied from someone else's kitchen is the single most common reason a first loaf fails.
- Mix & autolyse
- Bulk ferment
- Shape & bench
- Cold retard
- Bake
- Cool
Total:
Folds, not kneading
During the first two hours of the bulk, give the dough a set of stretch-and-folds every thirty minutes — four sets in all. Wet your hand, reach under one side of the dough, stretch it up and fold it over the top; turn the bowl a quarter and repeat, four times per set. Each set takes twenty seconds.
After the fourth set, leave it alone. The rest of the bulk is the culture's work, not yours, and every time the bowl is uncovered the dough loses heat and the clock resets a little.
Reading the dough
The timeline above is a forecast. The dough is the evidence. When they disagree, the dough wins.
| Sign | Under-fermented | Ready | Over-fermented |
|---|---|---|---|
| Volume | Barely grown | Up by half to three-quarters | Doubled or more, then sinking |
| Surface | Flat, tight | Domed, a few large bubbles at the edge | Flat again, many small bubbles, wet-looking |
| Poke test | Springs back fast and fully | Springs back slowly, leaves a shallow dent | Does not spring back; the dent stays or the dough deflates |
| Feel | Dense, heavy | Airy, holds together when lifted | Slack, tears, will not hold a shape |
Before Part 4
Stop the bulk when the dough is ready, not when the timer says so. Ready is: grown by half to three-quarters, domed, slow to spring back from a poke. If in doubt, stop slightly early — an under-fermented dough still makes decent bread, an over-fermented one makes a flat sour disc that no shaping can rescue.
