What’s Really Happening Inside Your Dough When You Stretch and Fold

The stretch and fold method is a technique many sourdough bakers follow simply because it’s written into a recipe. But understanding why it works can completely change how you approach your dough—and ultimately, your bread.

At its core, stretch and fold is about developing gluten, the protein network that gives bread its structure. When flour and water first mix, the dough is shaggy and disorganized. Stretching and folding creates order in that chaos. Each round helps to align and strengthen the gluten strands, forming the internal scaffolding that supports the dough as it ferments and rises.

Unlike traditional kneading, which can be aggressive, stretch and fold is a more deliberate and gentle process. Think of it less as "working" the dough and more as coaxing it into form. Stretching gently elongates the gluten strands, improving the dough’s extensibility—its ability to stretch without tearing. Folding then layers these aligned strands, bringing them close enough to form stronger bonds, especially disulfide bonds. These tiny molecular connections give the dough its elasticity—its ability to spring back.

This dual action—stretch for extensibility, fold for strength—is what transforms a wet, sticky mass into a cohesive, buoyant dough capable of holding the gas produced during fermentation.

Timing is just as important as the motion itself. Dough has a unique combination of elastic and viscous properties, a concept called viscoelasticity. Right after a fold, the gluten network tightens and becomes resistant to more movement. Resting between folds allows the dough to relax, making it more pliable for the next round. These rest periods aren’t downtime—they’re essential moments when the gluten reorganizes, the dough smooths out, and you set yourself up for even more effective development in the next stretch.

This carefully built structure becomes critical during bulk fermentation. As yeast activity ramps up and gas is produced, that internal gluten network is what traps those bubbles and creates rise. If the structure is weak or underdeveloped, the gas escapes or causes collapse, resulting in a flat or dense loaf. When done properly, stretch and folds set the foundation for volume, shape, and open crumb.

Temperature plays a major role in how and when to apply stretch and folds. Warmer dough ferments and develops faster, potentially requiring fewer folds or gentler handling. Cooler dough works more slowly and may benefit from additional rounds or longer rests. There's no universal rule here—just the need to observe and adapt.

One common mistake is treating stretch and folds like just a softer version of kneading. In truth, it’s a technique with its own rhythm and purpose. The motion should be intentional: a lift, a stretch, and a gentle fold over, not a mash or press. Another misconception is relying rigidly on a fixed number of sets. Instead, learning to read the dough—feeling its strength, its resistance, its smoothness—will tell you when it's ready.

In short, stretch and fold isn't just a checkbox on a recipe. It's a powerful tool that transforms dough on a microscopic level. It aligns and bonds gluten, builds structure, and prepares the dough to rise into a well-shaped, airy loaf. Mastering this process isn’t about memorizing steps—it’s about developing a feel for the dough and responding to what it needs.

The next time you're baking, pay close attention during your stretch and folds. Notice how the dough changes—how it strengthens, smooths, and holds its shape better with each round. That awareness is the beginning of real baking intuition, and it’s the key to consistently great sourdough.