In theory, pizza is easy to make. Throw some sauce and cheese on some dough, make it hot and voila. The innumerable lousy slices out there in the world, though, suggest that pizza’s also really easy to screw up. The cheese, especially, seems to be a minefield of potential mistakes. Sometimes it comes out too burnt, or not browned enough, or spotted with puddles of grease. Sometimes it just forms a plasticy-looking mat on top of the pie. 

Cheese like this can turn you off to the idea of eating before you even take a bite, so getting it to look just right, pie after pie, is not an insignificant problem for pizza makers. And it only gets more complicated if you’re using a blend of cheeses instead of just the traditional mozzarella. So which blends work best? To find out, a group of food scientists turned not to hungry humans, but to a computer, which could give them quantified values for a cheese’s “baking properties and performance” like color, color uniformity, browning, and blistering.

The team bought some mozzarella, cheddar, colby, edam, emmental, gruyere, and provolone, made a bunch of pizzas with them, and then used a program called LensEye to analyze and evaluate their pies. When they had an idea of how the cheeses looked and behaved after baking, they looked at which characteristics of the cheeses (like elasticity, moisture content and melting temperature) contributed to their appearance. 

They found that the cheeses that make for the best looking pizza are mozzarella, gruyere and provolone. The classic mozzarella, the researchers say, had the highest moisture content of the seven cheeses, less free oil (the oil that pools on the surface of melted cheese), more elasticity, and “a unique stretchability.” So when mozzarella bakes on top of a pizza, the moisture in it creates steam that makes it bubble and blister, its stretchiness lets those bubbles grow without bursting, and less surface oil means it dehydrates easily, creating a large, dry surface that browns evenly and gives the pizza an appealing, non-uniform color.

Gruyere and provolone are good choices to mix in with mozzarella if you want to punch up your flavor, the researchers say. The two cheese had similar baking performances, and both have lower moisture contents and higher free oil amounts than mozzarella. That leads to even, but not intensive, browning and fewer burnt spots on blisters than mozzarella.

Meanwhile, the rest of the pack barely blistered, and therefore didn’t brown well, because they weren’t stretchy enough and, in the case of emmental, because there wasn’t enough water to generate the steam needed to bubble. You could throw them on a pizza if you really liked their flavor, but the finished product wouldn’t look as nice.