When you're about to dig into a pizza, those bubbles of golden brown cheese on top are always a good sign. Understanding the value of a pie spotted with perfectly crisp cheese, a group of scientists in New Zealand set out to find which cheeses create the perfect topping.
In a study published in the Journal of Food Science, researchers from the University of Auckland studied the performance of seven cheeses including mozzarella, cheddar, Colby, Edam, Emmental, Gruyere and provolone on a pizza. The cheeses were baked on top of a basic pizza crust and evaluated based on their color, color uniformity and how they browned and blistered in the oven. Sauce was not used in the experiment because it can contribute extra moisture.
"So at first sight it seems really trivial, but actually it's a huge combination of things that contribute to that discreet patch of brown blistering across the pizza," said Bryony James in the video above, a PhD from the University of Auckland.
Looking for a quantified numeric description of appearance, James and her colleagues used a special custom-built device with a high resolution SLR camera rather than actual humans to study how the cheese melted. The device was attached to custom imaging analysis software with algorithms to quantify color and uniformity.
The researchers found a mixture of mozzarella and cheddar cheeses creates the ultimate bubbly, melted topping. The magic cheese duo works best due to a number of factors including the cheeses' rheology, free oil, transition temperature, elasticity and water activity.