Whatever your pizza preference—thin crust, or thick, topped with pepperoni, peppers or anchovies—the warm, goeey goodness of melted cheese on a good pizza crust is key to the pleasure of pizza.
Scientists, however, don't like to leave anything to chance or anecdotal evidence. Even cheese pizza can be subject to careful experimentation to get at the empirical roots of its deliciousness.
So a group of scientists from China, New Zealand and the U.K. got together to test one particular component of those pies: the cheese. Mozzarella is the choice cheese for most pizzas—but why?
The scientists experimented with mozzarella, cheddar, colby, edam, emmental, gruyere and provolone, which they distributed on pizza crusts and baked in the oven. During and after baking, they measured a specific set of characteristics, including elasticity, color, moisture and oil content. Here's the BBC Future on why those particular parameters are so important in pizza-making:
As cheese heats up, the water trapped within it – between strands of protein and globules of fat – starts to boil. It evaporates into steam, which gathers together to make a growing bubble in the cheese. If the cheese becomes elastic as it melts, the bubble will be able to stretch large. If the cheese is less stretchy, the bubble will stay small. Meanwhile, as the steam has been consolidating itself into a bubble, oil leaks out of the melting cheese to form a slick on top of the pizza. The top of a large bubble will break the surface of the oil and be exposed directly to the oven's heat, which will evaporate the rest of the water in the cheese and brown it. But if there is too much oil, even a large bubble won't break through the layer and it will remain a more pasty shade.
Mozzarella's unique elasticity and its water and oil content, the scientists found, produces the perfect consistency—bubbly and stringy yet intact—that we look for in pizza. It also browns nicely, creating a mottled, tasty top, but it does not collect pools of grease, either.
All of the other cheeses contained either too much or too little moisture or oil to pull this feat off, BBC Future explains. Those cheeses create bubbles that never burst or a disconnected pattern of cheese confetti or a unsatisfyingly flaccid sheet that slid off in one bite.
For pizza makers and eaters alike, the message is clear, the authors write: unless you're attempting something completely non-traditional, stick with a mozzarella base. You can always add those fancy other cheeses "to meet the specific preferences of consumers," but best to include the master of melt, mozzarella, in that mix, too.