Why Do Mozzarella Sticks Explode? (Explained!)

Mozzarella sticks explode due to high moisture content and rapid heating, causing steam build-up. Cooking from frozen at moderate temperatures, not overcooking, and allowing them to rest before eating can prevent explosions. Poking holes in them before microwaving also helps.

What is the Science Behind Melting Cheese?

Before I get specifically into why mozzarella sticks explode, it’s helpful to understand the science behind how the cheese melts. 

It’s a bit complicated, so stick with me!

Essentially, cheese is a combination of protein, fat, and water.

The proteins are called caseins, and when rennet is added to the milk during the cheesemaking process, the casein breaks down and clumps together. 

As they do this, they trap fat and moisture.

When cheese is heated, it breaks down the casein “prison” and allows the fat to escape.

So, that melted, gooey cheese we all love so much is actually down to leaking fat!

The moisture content of cheese also makes a difference. 

So, as regards mozzarella, it has a moisture content of between 45% and 52%, which quickly turns to steam when heated.

The combination of broken protein molecules and hot steam causes the cheese to melt quickly and evenly.

Perfect for a mozzarella stick! 

What Are the Factors That Affect Mozzarella Stick Explosions?

Let’s look at the different factors that, when all added together, could cause a mozzarella stick explosion!

Surprisingly, not all mozzarella has the same melting point and texture. 

Primarily, there is the better quality fresh mozzarella and then the so-called cheaper pizza mozzarella.

Typically, mozzarella sticks are made from the less expensive option, which has a lower moisture content and is more solid.

This ensures that the sticks retain their shape and melt easily.

But, of course, because this type of mozzarella melts quickly, it can explode in a short space of time.

An alternative would be to use fresh mozzarella, but realistically, it wouldn’t give that melty stringiness we are looking for; it is better used in salads.  

The next important factor is the temperature at which you cook the mozzarella sticks.

Put simply, if it’s too hot, there is more likely to be an explosion.

And that applies no matter which method you use, whether it be in oil, an air fryer, a microwave, or in the oven. 

The cheese will heat up too quickly.

Once you see a crack start to appear in your mozzarella sticks, they should be removed from the heat source immediately. 

And above all, always cook them from frozen, otherwise, the center will cook too quickly and explode, before the breadcrumbs get their nice crispiness.

My Thoughts

  • Using a pizza mozzarella rather than the fresh option will ensure your cheese has the right amount of moisture content
  • Don’t cook the mozzarella sticks at too high a temperature
  • Or cook them for too long
  • Always cook the mozzarella sticks from frozen
  • For your safety, allow the sticks to cool slightly before biting into them

It may take some experimentation to find out how to cook your mozzarella sticks for the best results.

And, on a similar subject, please read about whether it’s a good idea to microwave mozzarella.

What techniques have you found effective in preventing mozzarella sticks from exploding when cooking them?

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