Why Your Sourdough Keeps Spreading Flat (And How to Fix Your Shaping)

I spent my first six months of sourdough baking convinced that my flat loaves were a fermentation problem. I adjusted hydration. I changed flour. I experimented with bulk ferment times. I even bought a thermometer to monitor dough temperature. The loaves kept spreading into sad, flat discs the moment they hit the oven.

Then I watched a professional baker shape a loaf, and everything clicked. My fermentation was fine. My shaping was terrible. I was handling the dough like it owed me money, degassing it completely, and creating zero surface tension. No wonder it spread flat.

What Shaping Actually Does

Shaping isn't just about making the dough look like a loaf. It serves three critical purposes that directly affect your final bread:

1. Creates surface tension. A tight "skin" on the outside of the loaf holds the dough's shape as it rises in the oven. Without surface tension, the dough spreads sideways instead of springing upward
2. Organizes the internal structure. Shaping aligns the gluten network, creating a more even crumb with better gas retention
3. Determines the final form. Boule (round), batard (oval), or baguette. The shaping method creates the shape that baking sets permanently

Pre-Shaping: The Step Most Beginners Skip

Pre-shaping is a gentle first round of shaping that happens right after you turn the dough out of the bulk fermentation container. It's the most commonly skipped step in home sourdough baking, and skipping it is why so many loaves end up flat.

How to pre-shape a boule (round)

1. Flour your work surface lightly. Turn the dough out of its container, smooth side down
2. Using a bench scraper and your non-dominant hand, gently fold the edges toward the center. Don't press hard, you're not trying to degas the dough
3. Flip the dough over so the smooth side is up
4. Using the bench scraper, drag the dough toward you across the un-floured surface. The friction creates tension on the surface. Rotate 90 degrees and drag again. Repeat 3-4 times until the ball feels taut
5. Leave it alone. Cover with a towel and let it rest for 20-30 minutes

The Bench Rest: Why Patience Pays Off

After pre-shaping, the dough needs to relax for 20-30 minutes. This bench rest allows the gluten to de-stress so you can shape it again without the dough fighting back and tearing.

You'll know it's ready when the dough has relaxed and spread slightly but still holds a general round shape. If it's spread into a complete pancake, your dough might be over-fermented or too high in hydration. If it hasn't relaxed at all and still feels tight and springy, give it another 10 minutes.

Final Shaping: Where the Magic Happens

Final shape for a boule

1. Lightly flour the top of the rested dough. Flip it over with a bench scraper so the floured side is down
2. You're now looking at the sticky underside. Grab the bottom edge and fold it up to the center. Grab the top edge and fold it down to the center, slightly overlapping
3. Fold the left side to the center. Fold the right side to the center, overlapping
4. Now roll the whole package over so the seam is on the bottom and the smooth, taut side is on top
5. Cup your hands around the dough and use the same bench scraper dragging technique from pre-shaping. Drag toward you, rotate, drag again. Build tension until the surface is smooth and the dough holds a tall, round shape
6. Place seam-side up into a well-floured banneton (proofing basket) or a bowl lined with a floured towel

Final shape for a batard (oval)

1. Flour and flip the dough as with the boule
2. Fold the bottom edge up to roughly two-thirds. Press gently to seal
3. Fold the top edge down to meet the bottom fold. Press to seal
4. Now roll the entire piece toward you, seam side down, using the heels of your hands to seal as you roll
5. With the seam underneath, gently rock the dough back and forth to elongate to your desired length
6. Place seam-side up in an oval banneton or on a couche

Common Shaping Mistakes and Fixes

The dough sticks to everything

Your dough is probably too wet or under-developed. Use a bit more flour on your hands (not the work surface). Wet your bench scraper. And next time, consider reducing hydration by 5% or adding one more set of stretch and folds during bulk fermentation to develop more strength.

The dough tears during shaping

You're being too aggressive. Shaping should be gentle and deliberate. If the dough tears, stop, let it rest for 10 minutes, and try again with a lighter touch. Tears can also mean your gluten is under-developed, so check your bulk fermentation process.

The shaped dough deflates immediately

This is over-fermentation, not a shaping problem. If the dough feels like a water balloon and has no structural integrity, it has gone too far during bulk ferment. Reduce your bulk ferment time by 30-60 minutes next time. Shaping can only do so much with over-proofed dough.

One side is always flatter than the other

Your tension isn't even. When dragging the dough, make sure you're rotating and building tension from all sides equally. Most right-handed people create more tension on the left side. Be conscious of it and compensate.

The Proof: Don't Undo Your Hard Work

After shaping, your dough goes into a banneton for its final proof. This can happen at room temperature (1-2 hours) or in the fridge overnight (8-16 hours). The fridge method is easier to time and produces better flavor, so I recommend it for most home bakers.

When you turn the dough out of the banneton onto your baking surface, do it confidently and quickly. A slow, hesitant flip lets the dough stretch and degas. One decisive motion, upside down onto the parchment or peel, and you're done.

How Shaping Connects to Oven Spring

Oven spring, that dramatic rise in the first 15 minutes of baking, is the reward for good shaping. The tight surface tension holds the expanding gases in, forcing the dough upward instead of outward. A properly scored loaf with good surface tension will bloom open beautifully, creating that coveted ear and dramatic rise.

If you're getting good fermentation (the dough doubles during bulk, passes the poke test) but still getting flat loaves, shaping is almost certainly the issue. Practice the pre-shape and final shape sequence a few times, focus on surface tension, and you'll see immediate improvement.