This difference is important.
When butter melts, it becomes a liquid that may foam or sizzle as moisture escapes.
Cheese, however, can maintain enough structure to trap expanding steam and air temporarily.
That's why it can form rounded blisters rather than simply becoming a smooth puddle.
Food researchers have specifically investigated these melting and blistering properties in mozzarella because they matter to pizza manufacturers, restaurants, and home cooks alike.
What appears to be a tiny surface imperfection is actually the result of several interacting physical processes.
3. The Type of Cheese Makes a Big Difference
Not all cheese behaves the same way when exposed to high heat.
If you've ever experimented with different varieties on homemade pizza, you may already have noticed this.
Some cheeses melt into smooth, creamy layers.
Others develop brown spots, release oil, form bubbles, or retain some of their original shape.
These differences depend on moisture, acidity, protein structure, salt content, fat levels, and age.
