Pizza cooked in a microwave does not rise the way it does in a conventional oven where it has 2 or 3 min. of rise time. To help a microwave pizza crust rise, bakers can “increase the amount of yeast or add a chemical leavening, which releases leavening power quite rapidly, or bakers can use fat flakes, which are not true leavening, but give dough the characteristics of leavening when those fat flakes melt out,” Lehmann adds.

Most microwaveable pizzas work just as well in a conventional oven, however exceptions do exist. “If a microwaveable product has been formulated with a topical mailose spray then that would have to be omitted for the counterpart that would be baked in a conventional oven,” Lehmann notes. Mailose is a type of sugar that is often applied to the edge of a pizza crust and turns brown when exposed to heat. Aside from mailose, no other formula changes would be necessary, Lehmann says.

Preventing the crust from drying out when the consumer bakes it is always a challenge. Rehinhart solved this problem when creating a pizza for Amy's Kitchen by adding more moisture to the dough. Moisture, he says, protects the dough during a re-bake. “One of the reasons more pizza companies don't add extra moisture is when you have wetter, stickier dough you need specialized equipment or you need a lot of hands on the dough, so it is more costly.” Now that special equipment is more readily available, he predicts larger companies will begin using wetter doughs to achieve better pizzeria-style crusts.

Crust thickness

Dough for both thin crust and thick crust pizzas can be made from the same formulation. “It has more to do with how thick bakers roll the dough before they shape it, and whether they allow it to rise before they bake it,” Reinhart says. “From the same dough you can make 30 types of pizza crust because the dough can be changed just by how thick you roll it out, how hot you bake it or how long you let it rise before you bake it,” he adds. Thick crust is baked at a lower temperature than thin crust.

In thin crust, yeast levels and mix times generally are less. The amount of oil or shortening used also plays a role. “When we're making a deep dish or thick crust pizza, we find the dough is better if we use shortening rather than oil,” Lehmann says. “The amount of shortening or oil is increased if we're making a deep dish or thick crust. A thin crust contains about 2 percent fat, while a deep dish may contain double or triple that amount in order to adequately tenderize the dough. “You have 35 percent to 40 percent more dough on a deep dish or thick crust pizza than you do on the same size thin crust pizza; because of that, you're getting a larger bread portion, and that bread portion has to be more savory,” he adds. Fat improves the palatability of a product.

Whole grain crust

While whole grain crust has yet to gain popularity with pizza lovers, more consumers are requesting whole grain and multi-grain crusts. “I think American tastes are beginning to gravitate in that direction,” Lehmann says. “Children who have not grown up with whole grain options might be less likely to buy into a whole grain pizza crust. Children between the ages of three and five years have been exposed to whole grains much more than children in the past.” He predicts it may be another five years before whole grain crust catches on.

It is easier to make a white flour pizza dough taste good than a whole wheat dough, because white flour is naturally sweeter, Reinhart says. “The whole grain works against the things we like most in dough, such as the sweetness of the flour and tenderness of the dough. It is more challenging to make a delicious whole grain crust.” However, techniques for achieving this do exist, such as longer fermentation and increasing moisture content.

In addition, as whole grain crust has fallen from popularity in the past, many bakers have forgotten how to make it properly. A whole wheat crust does not contain white flour, while a wheat crust might contain 50 percent white flour and 50 percent whole grain flour. “When dealing with whole grains, it is necessary to soak the whole wheat flour in water equal to two-thirds of its weight,” Lehmann notes.

First, mix the grains and water until it resembles the consistency of oatmeal, and allow it to sit for 1 hr. or more, or even refrigerate it overnight. The mix is known as a “soaker.” Some bakers make the mistake of adding enough water to create a normal feeling dough. “Then when the bran begins to hydrate, it soaks up so much water the dough gets dry, stiff and crusty. Worse, when it bakes, it hydrates further. The result is a crust that is extremely dry and brittle,” Lehmann says. Therefore, it is necessary to soak the whole wheat flour and afterward, add it into the dough and continue to formulate as a normal dough.

Self-rising vs. par-baked

Self-rising dough, also known as bake-to-rise dough, is designed to be stable at refrigerated temperatures. A consumer needs to bake it within 12 to 24 hr. of purchase. Once in the oven, the dough bakes fully, resulting in a fresh baked product. “You get the spring as you would with a muffin,” Reinhart adds. “Consumers were fascinated by the fact that the crust did rise and there was moisture and mouthfeel to the dough, partly because it wasn't overbaked the way other frozen pizzas often are.”

The other option is a par-baked crust, or traditional frozen pizza, where the crust is half-baked by the manufacturer and the consumer warms it back up in the microwave or oven until the crust turns brown. Because the yeast has been killed during the original bake, it does not rise further in the consumer's oven. “What you're actually doing is drying up moisture from the cheese, driving off moisture from the toppings and the crust. You end up with a crust that is extremely dry, the toppings are dry and the cheese is almost a bubble gum consistency,” Lehmann says.

In self-rising dough, yeast provides a good deal of the leavening or rising of the crust. The yeast activity can be controlled through temperature. “We mix our doughs cold enough at a low temperature, and we try to mix them between 65°F and 75°F. Ideally, we'd like to see them around 65°F to 70°F,” Lehmann says. Some bake-to-rise crusts use chemical leavening. “The correct chemical leavening to use in that application is sodium aluminum phosphate (SALP).”

SALP is a food acid bakers neutralize with baking soda. The neutralizing value for SALP is 100, so bakers would use 1 lb. of SALP for every 1 lb. of baking soda to make a complete baking powder. To apply this to the pizza dough, bakers encapsulate the material in fat, using 1 lb. of fat for every 1 lb. of active material. The fat protects the chemical leavening from the water in the dough until the jacket of fat melts away in the oven when it reaches 105°F to 110°F. When the fat melts away, the SALP plus baking soda begins generating CO2, which has a leavening effect on the dough, and the dough begins to rise, Lehmann explains.

Both chemical leavening and yeast have advantages. “If you add chemical leavening, you get a longer freezer life, but yeast will give you more of a fermentation flavor,” Donaldson notes.

“[Self rising] dough really did catch on, and I think they are getting better as bakers get more experienced with dough technology,” Reinhart says. “Now [manufacturers are] saying it's like pizzeria pizza. It may be closer than we've ever come to that; bakers understand how not to kill the dough at the factory.”