I get a lot of questions about pizza dough preparation – how to handle the dough, how to knead it, proof it, etc. But quite often these questions reveal to me that lots of people don’t understand the most basic concept of baking – how pizza dough rises.
Pizza dough rises when the yeast consumes sugar and produces carbon dioxide. This carbon dioxide fills the gluten pockets in the dough that were created during kneading and inflates them like a balloon. When this happens, the pizza dough increases substantially in volume and allows it to bake into a light and fluffy crust.
Let’s take this opportunity to do a quick refresher on how pizza dough rises and how you can use this knowledge to get the most out of your pizza dough. But if you’re trying to figure out why your pizza dough didn’t rise, I recently wrote a diagnostic guide that might be of help.
How Does Pizza Dough Rise
Pizza dough rises because of yeast. Yeast is what turns flour, water and salt into a living and feeding organism.
If you’ve ever made a batch of pizza dough – or any kind of dough really – and forgot to add yeast, you know what happens.
The dough just sits there like a lump of clay and doesn’t do anything. It doesn’t expand in volume and it doesn’t start to bubble over across the surface.
Another tip-off that you forgot to add yeast is the smell. Dough without yeast smells exactly like what you’d expect – a clump of wet flour. By contrast, a pizza dough with yeast in it will have a subtle hint of bread or beer.
This is because when yeast mixes with water and flour it comes alive and begins feeding. When yeast feeds on sugar, it produces gasses, alcohol and acids. This is when the dough starts to rise.
Yeast Fills The Dough With Gas
When the yeast in your pizza dough is activated, it starts to convert the starches of the flour into sugar. The yeast then consumes this sugar and produces carbon dioxide as a by-product in the same way that humans and other organisms pass gas after a meal (to put it politely).
This passed gas is the key to how pizza dough rises and it’s what gives pizza crust its characteristically puffy and light texture.
But while the yeast, flour and sugar is perfectly adequate to get the yeast activated and going, sometimes we want to speed the process along a bit. A great way to do this is by adding some extra sugar.
I usually add a spoonful of honey to my pizza dough recipes because it gives the yeast a bit of a head start while it’s busy converting starch to sugar. The added sugar also allows for some caramelization of the crust which is a nice touch when you’re baking pizza in a lower temperature home oven.
OK, so now we know that yeast produces gas and gas is what makes the pizza dough rise, you still might be wondering how this actually happens. Logically, you might assume that any gas created by the yeast would just escape into the air.
The answer to this question is the second core component to any good pizza dough–gluten.
Gluten Traps Gas And Expands
When you knead pizza dough, you’re not just folding and mixing the ingredients so it turns into a ball. What’s happening on the inside is actually incredibly crucial to what makes pizza dough rise.
As you knead the pizza dough you’re helping the flour come into contact with and completely absorb moisture. When this happens, the proteins in the flour mixes with the moisture and creates gluten.
Gluten is the stretchy and sticky substance that lets you stretch the dough without tearing it. Gluten is also why your pizza crust has a decent chew to it and doesn’t just break off and dissolve in your mouth like a cracker.
But in terms of why pizza dough rises, gluten serves a really important function. If you look at your dough while it’s resting you’ll see small bubbles start to form along the surface. These bubbles are made of gluten and are filled with the gasses produced by the yeast we talked about earlier.
Gluten gives the dough the strength and flexibility it needs for this gas to expand in the dough without bursting. When lots of these bubbles form simultaneously and start filling up with gas, this is why the pizza dough rises and expands in volume.
How Salt Affects Pizza Dough Rising
The main reason we add salt to pizza dough is because of taste. If you’ve ever forgotten to add salt to a dough recipe, you’ll know that the end result is edible but usually lacks flavor.
But many people don’t know that salt actually affects the way pizza dough rises in a very important way.
Salt absorbs the water that yeast needs to make the dough rise. Too much salt will prevent the dough from rising at all, while too little salt will cause the dough to rise too fast and ruin the structure of the crust. The perfect pizza dough has a salt content that accounts for how long you plan on letting the dough proof and rest.
To put things in a practical perspective, if you plan on letting your dough rest for 24-48 hours you probably want a higher salt content to slow the rising process. On the other hand, if you plan on using your dough the same day, you probably want a lower salt content so the dough will rise quickly.
My personal no-knead pizza dough recipe calls for a 11-18 hour rest before use, so I’ve adjusted the salt content to be a bit higher than normal. This makes sure the yeast doesn’t kick into overdrive and ruin my dough.
A pizza dough that rises and bakes into a perfect crust is often something we take for granted. But a firm understanding of why pizza dough rises in the first place is useful if you want to avoid problems with your pizza down the road.
For example, knowing that a good pizza dough has solid gluten pockets and lots of gas tells you that you should be gentle when handling the dough. In fact, most of the time when people get into trouble making pizza it’s because they inadvertently de-gassed their pizza dough while preparing it.
This can happen a couple of ways, but usually it’s because they used a rolling pin or were much too rough trying to stretch out the dough. This tears the gluten connections and lets out all the gas.
On the other hand, it’s common to see people ruin their pizza dough by simply not letting it proof long enough. This prevents the pizza dough from rising in the first place causing it to bake into a flat and dense crust.
So next time you’re making pizza dough remember that yeast creates gas and gluten traps that gas so the dough can rise. As long as you don’t disturb this process too much, your pizza dough is going to bake into a delicious and fluffy pizza every time.