the first 10 minutes: the moment your dough becomes bread

You shaped it.
You fermented it.
You scored it.
You put it in the oven.

And then something extraordinary happens.

For the next few minutes, your dough is neither simply dough nor bread.

It is changing.

1. The final expansion

The first thing you notice is the rise.

Your loaf suddenly becomes larger, sometimes dramatically so.

This is called oven spring.

But it isn’t simply “the yeast making more bubbles”.

As the dough heats, the gases already trapped inside it expand. Water also begins turning into vapour, increasing pressure inside the dough. Yeast can continue producing gas for a short time before heat stops its activity.  

The result is a final burst of expansion.

Your loaf is, quite literally, stretching from the inside out.

2. The invisible architecture

Look closely at a sourdough crumb and you are looking at an architecture of tiny cells.

Before baking, those cells are surrounded by thin films of dough containing gluten, starch and water.

During baking, those walls stretch as the gases inside them expand.

Some remain intact.

Some open.

Some merge.

The final crumb is the result of this microscopic battle between pressure, elasticity, heat and structure.  

That is why two loaves made from the same recipe can end up with completely different interiors.

The bread isn’t simply “rising”.

Its internal architecture is being built.

3. Why steam matters

This is where things get even more interesting.

The surface of your dough is heating rapidly.

Without enough moisture around it, the outer layer can begin to dry and set too early.

Steam delays that process.

It keeps the surface more flexible while the loaf is expanding, giving the dough more time to stretch before the crust becomes rigid. Research has shown that steam affects surface starch gelatinisation, crust structure and moisture movement.  

Think of it as giving your loaf a little more time to grow before the door closes.

4. Then the structure changes

Eventually, expansion has to stop.

Heat begins transforming the dough itself.

Starch granules swell and gelatinise. Proteins change and the dough progressively stiffens. These changes help transform the soft, extensible dough into the much more stable structure we recognise as bread.  

This is one of the great moments in baking:

the bread has to know when to stop growing.

Too early, and you can lose volume.

Too late, and the structure may not hold properly.

The beautiful loaf you pull from the oven is the result of getting that transition right.

5. Your score is a decision

And suddenly, your scoring makes more sense.

That cut you made before putting the loaf into the oven isn’t decoration.

It is an intentional weak point in the surface.

As pressure builds and the loaf expands, the score gives the bread somewhere to open.

That is why the direction, depth and position of a score can influence the final shape of the loaf.

You aren’t simply cutting the bread.

You are telling it where to grow.

6. The moment everything becomes permanent

At some point, the transformation is essentially irreversible.

The flexible network has become a set crumb structure.

The surface loses moisture and becomes the crust.

The colours deepen.

Aroma compounds develop.

And the loaf that entered the oven as a living, fermenting dough has become something completely different.

Bread.

But here is the beautiful part

When you look at a sourdough loaf, you are seeing the result of thousands of tiny events that happened long before you sliced it.

The flour determined how the dough behaved.

The fermentation created the gases.

Your hands developed its structure.

The banneton supported its final shape.

Your scoring decided where it would open.

The oven transformed everything.

And for those first few minutes…

the loaf was still deciding what it wanted to become.

That is why sourdough is so fascinating.

You don’t completely control the bread.

You create the conditions.

Then you watch.

And somewhere between flour, water, fermentation, heat and time, something happens that you cannot quite manufacture.

You can only make room for it.

The next time you put a loaf in the oven, don’t walk away.

Watch it.

For the first ten minutes, you’re watching dough become bread.

And once you understand what is happening inside that loaf…

you will never look at your sourdough the same way again.