Back then, Domino's pizza had developed the standard for pizza boxes. Their pizzas were around 180 to 200 degrees out of the oven, and they aimed to maintain a post-baking temperature of 140 degrees for 45 minutes. Kosar needed to beat that. Domino's boxes were designed to vent steam and prevent a soggy crust, but at the cost of losing delicious heat. Ingrid's first bags retained heat by trapping it behind layers of polyester and nylon. This kept the pizza warm, and the vents on the pizza box kept it crispy. Even more impressive, pizzas in the bag would lose only around 5 degrees an hour. A delivery guy could leave the pizzeria, play Pac-Man, and flirt with some mallrats for 20 minutes and still deliver a piping-hot pizza.
After pestering Domino's to order from her, they finally caved and bought $10,000 worth of thermal bags. Then other pizza chains signed on. And then the U.S. government came knocking and ordered bags for restaurants on military bases. Then she got innovative again and created the HeatWave, a thermal bag with a built-in heater. Domino's ordered 90,000 HeatWaves, every one of them made by hand by her relatively small workforce.
Unfortunately, her patents expired in the early 2000s. At that point, everyone with access to sewing machines and a cheap workforce flooded the market with their knockoffs. She eventually had to file for bankruptcy. But don't feel too bad for her. She came up with another food-industry innovation: large tarps that maintain even temperatures for raising bread dough. She sells a ton of them to Panera Bread. So the next time you find yourself eating a blisteringly hot pizza that 30 minutes before was pale, flaccid, room-temperature dough, thank Ingrid. And while you're at it, also thank Carmela Vitale, the woman who invented that little plastic table thing that prevents the box top from smushing down on the pizza. Then go ahead -- pack another bowl and play some more Smash Bros.