You did everything right. Fed the starter, mixed the dough, waited the hours the recipe promised, and still your loaf turned the banneton out into a sad, spreading disc. Before you blame your starter or your flour, look at your handling. Nine times out of ten, a flat loaf and a collapsing crumb come down to one thing: weak dough that never built enough structure to hold its own gas. The good news is that fixing it doesn’t mean ten minutes of white-knuckle kneading. It means stretch and folds, and they take about ten seconds each.
Stretch and folds are the quiet workhorse of modern sourdough. They’re how you turn a slack, sticky, shapeless mass into a smooth, elastic dough that rises up instead of out, all without a stand mixer and without wearing yourself out. Here’s exactly what they do, how to perform them, how many you actually need, and, just as importantly, when to stop.
What a stretch and fold actually does
When you mix flour and water, you create gluten, the protein network that traps the carbon dioxide your starter produces. Straight out of the mix, that network is disorganized and floppy. Kneading is one way to organize it. Stretching and folding is another, and it’s gentler and better suited to the wet doughs sourdough thrives on.
Each fold aligns the gluten strands and stacks tension into the dough, the same way folding a sheet of paper over and over makes it stiffer and springier. Do a set every 30 to 45 minutes during the first part of bulk fermentation and you steadily transform a dough that pools into one that domes. You’ll feel it happen: the first fold fights you and tears, and by the third the dough stretches thin and pulls back like elastic. That change is the whole point.
How to do a basic stretch and fold
You don’t need any tools, just a bowl of dough and a small dish of water to keep your hands from sticking. Here’s the move, step by step:
1. Wet one hand lightly. 2. Slide it under one side of the dough, grab it, and lift it up until it stretches, without ripping. 3. Fold that flap over to the opposite side. 4. Rotate the bowl a quarter turn and repeat. Four lifts, one from each side, is a complete set. The dough should end up as a tidier, tighter package than when you started.
Cover it and walk away for 30 to 45 minutes, then come back and do another set. Keep your touch light. You’re not punching or squeezing, you’re lifting and laying. If the dough tears every time on an early set, it just isn’t developed yet, so ease off and let time do some of the work between folds.
Coil folds: the gentler cousin
Once your dough is airy and full of gas, aggressive stretching can deflate it. That’s when coil folds take over. Instead of pulling the dough sideways, you lift it from the middle with both hands until the two ends release from the container and tuck underneath, forming a coil. Set it down, rotate 90 degrees, and lift again.
Coil folds add tension without degassing the dough, which makes them ideal for the back half of bulk fermentation and for high-hydration doughs that have gone pillowy. Many bakers start a batch with two sets of classic stretch and folds, then switch to two coil folds as the dough gets lively. Use whichever keeps the dough strong without knocking the air out.
How many folds do you actually need?
There’s no magic number, but a useful default is three to four sets, spaced 30 to 45 minutes apart, all within the first couple of hours of bulk fermentation. That’s when the dough is most receptive and gluten development pays off the most. After that, folding does little except risk tearing a gassy dough.
Read the dough, not the clock. A strong bread flour needs fewer folds than a weak all-purpose or a whole-grain blend that fights to hold structure. Higher-hydration doughs generally want more sets to firm up; stiffer doughs want fewer. If your dough is already smooth, elastic, and holding a dome after two sets, you’re done. Piling on more folds won’t make it stronger, it’ll just start deflating the gas you worked to build.
When to stop folding
This is where most flat loaves are actually lost, not from too few folds but from folding too long into fermentation. Every fold you do near the end of bulk knocks out gas the dough won’t have time to replace before shaping. Stop while the dough still has work left to rise.
Your signals to quit: the dough has grown noticeably (roughly 30 to 50 percent, depending on your process), the surface has gone smooth and slightly domed, you can see bubbles forming under the surface and around the edges, and it jiggles like a set custard when you shake the container. Once you see those, hands off. Let it finish bulk undisturbed, then move to shaping.
Fitting folds into a real schedule
The 30-to-45-minute rhythm sounds demanding, but it’s forgiving in practice. You don’t have to hover. Set a phone timer, do a 10-second fold, and go back to your day. If life gets in the way and you miss a fold by 20 minutes, the dough won’t care. If you have to leave the house, do your folds a little closer together up front and let the dough bulk on its own after.
Kitchen temperature changes the timing too. In a warm room, fermentation moves fast, so get your folds done early and expect the whole bulk to finish sooner. In a cold kitchen, everything stretches out and you have more slack to work with. When in doubt, watch the dough’s strength and rise rather than counting minutes.
Common stretch-and-fold mistakes
Folding a dough that’s already strong. More is not better. Once it’s elastic and domed, extra folds just degas it.
Being too rough. Ripping the dough tears the very gluten you’re trying to build. Lift slowly and let it stretch on its own.
Dry hands. Sticky dough tears and frustrates you into overworking it. A quick dip in water fixes it instantly, without adding flour that would stiffen the dough.
Folding too late. Doing a hard stretch-and-fold set an hour before shaping undoes your rise. Front-load the folds and finish bulk hands-off.
Why this fixes flat, collapsing loaves
Come back to that spreading disc from the beginning. A dough with a weak gluten network can’t cage the gas from fermentation, so instead of pushing the loaf upward it leaks out sideways the moment you turn it out to bake. Stretch and folds build the strength that holds that gas in place, so the loaf rises tall, springs in the oven, and sets with an even, open crumb instead of a dense, gummy pancake.
If you’ve been chasing better bread through fancier flour or a more elaborate starter routine, try fixing your handling first. A few well-timed folds are usually the difference between a loaf that slumps and one that stands up proud.
Want to see exactly what a strong dough looks and jiggles like at each stage? The full stretch-and-fold walkthrough, including the coil-fold hand motion and the poke test for when to stop, lives on the LoafLovers YouTube channel, and our free sourdough troubleshooting guide breaks down the rest of the flat-loaf fixes. No hard sell, just the answers you need mid-bake.