The Science Behind the Bubbles
Cheese is made of proteins, fats, and water.
When exposed to temperatures above 400°F (200°C), the moisture inside the cheese rapidly turns into steam.
If that steam cannot escape immediately, it pushes upward, stretching the melted cheese into small domes.
Once the pizza is removed from the oven, many of these bubbles collapse as they cool, while others remain slightly raised.
This is simply part of the baking process—not a sign that anything is wrong.
Why Some Pizzas Bubble More Than Others
Not every pizza develops noticeable bubbles.
Several factors influence how many appear.
1. High Oven Temperature
Professional pizza ovens often cook between 700°F and 900°F, creating steam much faster than a home oven.
Higher temperatures increase bubble formation.
2. Type of Cheese
Fresh mozzarella contains more moisture than low-moisture mozzarella.
More moisture means more steam—and often more bubbles.
3. Cheese Distribution
If cheese is layered unevenly, thicker sections can trap additional moisture beneath the surface.
4. Dough Expansion
As pizza dough rises in the oven, it releases gases that may push upward against the cheese.
5. Baking Time
Longer baking times allow bubbles to grow larger before eventually browning.
Are Cheese Bubbles Safe to Eat?
Absolutely.
These bubbles are simply made of:
- Steam
- Air
- Melted cheese
They contain nothing harmful and don’t indicate contamination or spoilage.
In fact, many pizza lovers intentionally seek out browned cheese bubbles because they develop extra flavor through caramelization.
