You place the dough into a hot oven full of hope.

For the first few minutes, this is the moment every sourdough baker waits for. A well-fermented loaf should rise quickly, open beautifully along the score, and develop that dramatic ear everyone loves.

Instead... almost nothing happens.

The loaf stays low, the score barely opens, and the bread looks much flatter than expected.

This is called poor oven spring, and it is one of the clearest signs that something happened before the loaf ever reached the oven.

Oven spring is the rapid expansion that happens during the first 10–15 minutes of baking.

As the dough heats up, the yeast produces a final burst of carbon dioxide, the gases already trapped inside the dough expand, and steam forms within the loaf. If the gluten network is strong enough, the bread rises dramatically before the crust sets.

Good oven spring creates:

When one part of that process goes wrong, oven spring becomes weak.

The number one reason for poor oven spring is overproofing.

By the time the loaf enters the oven, the yeast has already used most of its available food and the gluten has weakened.

There is very little energy left for that final burst of expansion.

The loaf may look beautifully proofed, but once baked it hardly rises at all.

This surprises many bakers.

Underproofed dough often has plenty of strength, but it hasn't developed enough internal gas during fermentation.

Instead of expanding evenly, it may burst unpredictably, tear along the sides, or produce a dense crumb.

The goal is not simply to avoid overproofing.

The goal is to bake at the right moment.

Even perfectly proofed dough won't spring well if the starter isn't strong enough.

A healthy starter should rise reliably after feeding and show plenty of bubbles before being mixed into the dough.

If the starter is sluggish, the dough simply won't have enough fermentation power.

Oven spring depends on more than fermentation.

The dough also needs a strong gluten network.

Without enough gluten development, the expanding gases escape instead of lifting the loaf.

Good mixing, stretch-and-folds, and proper shaping all help create the structure needed for a strong rise.

Steam keeps the surface of the dough flexible during the first stage of baking.

Without enough steam, the crust hardens too quickly.

Once that happens, the loaf cannot continue expanding.

That is why Dutch ovens and steam-assisted baking often produce much better oven spring than dry ovens.

A score is more than decoration.

It gives the loaf a controlled place to expand.

If the score is too shallow, the bread may not open properly.

If it is too deep or made at the wrong angle, oven spring may also suffer.

If your sourdough rarely rises well in the oven, focus on the basics:

Small improvements in several areas usually produce much better results than changing only one thing.

Poor oven spring isn't a random disappointment.

It's a clue.

The loaf is telling you that something during fermentation, gluten development, proofing, or baking wasn't quite right.

Once you learn to recognize those signals, every loaf becomes easier to understand—and every bake becomes a little better than the last.