Ernesto Di Maio can’t eat standard pizza. The materials scientist from Naples, Italy, has a severe yeast allergy that causes him to break out in hives. Now, in work published in the journal Physics of Fluids, Di Maio and his colleagues have invented a yeast-free method of leavening pizza dough that tastes "exactly like the yeast pizza," he tells NPR’s Ari Daniel.
Typical pizza doughs, like most breads, rely on yeast to ferment and produce carbon dioxide bubbles. As the pizza bakes, the air bubbles are cooked into the dough, creating a crust with a fluffy, airy texture. Di Maio and his team were curious if they could produce the same bubbly effect without yeast.
"The aim was to try to make the same texture that we love so much in pizza without a chemical agent," says study co-author Rossana Pasquino, a University of Naples chemical engineer, to Science's George Musser.
To artificially aerate the crust, the team placed the dough—a mixture of flour, water, and salt—into an autoclave, a chamber with controlled pressure and temperature settings. They then flooded the golf ball–sized dough with gas at high pressure, similar to carbonating a soda. When they gradually released the pressure and increased the heat inside the chamber, the team watched the dough rise.
"The invention is grounded on a deep knowledge of what's going on while cooking," Di Maio says to CNN’s Kristen Rogers via email. "We had fun in the lab."
One challenge that researchers ran into was timing the pressure and temperature to produce maximum bubbling when the dough was setting. Study co-author Paolo Iaccarino, who works part-time in an Italian pizzeria, used a thermometer to measure the dough’s temperature in the wood-fired oven, according to Nicoletta Lanese for Live Science.
Because their autoclave is roughly the size of a toaster oven, the team ended up with a set of miniature pizzas. When they sampled their creation, “it was nice and crusty and soft," Di Maio tells Science.
Yeast also imparts flavor into the dough as it ferments, which makes some skeptical that the lab-puffed crusts will be as tasty as standard yeast-leavened versions.
"Yeast does so many things to dough besides fermentation, like the flavors that you find, the complexity of aromas," says Francisco Migoya, head chef at the culinary innovation collective Modernist Cuisine, who wasn't involved in the experiment, to NPR. Like creating a sourdough starter, Migoya notes, small amounts of airborne yeast in our environment will find their way into the dough, making a truly yeast-free dough is hard to achieve.
The researchers say their dough isn't intended for all pizza enthusiasts, but as an alternative for those with dietary restrictions, like Di Maio. The team is optimistic that their aeration technique might improve the texture of gluten-free pizzas, too.
"This new technology can drive the development of new products, new dough formulations, and specific recipes for food intolerance, hopefully helping people enjoy healthy and tasty food," Di Maio says in a press release.
Following the success of their pint sized–pies, the Italian team plans to use a larger autoclave to produce standard-size pizzas.