Mushrooms have the power to retain a delightful texture across a wide range of heat settings and cooking times. So, how is it possible that mushrooms are basically un-overcook-able? According to Cook’s Illustrated, a mushroom’s strength can be attributed to its cell walls, which are made of chitin, a fibrous substance found in fungi that makes up their molecular structure. After a number of scientific studies over the years, it’s been shown that the polymer is very heat-resistant, unlike proteins in meat or pectin in fruits and vegetables, foods that can be easily burned.
Dan Souza, editor-in-chief of Cook’s Illustrated and executive editor of “Cook’s Science” at America’s Test Kitchen, conducted an experiment to prove the vigor of mushrooms. He gathered a portobello mushroom, zucchini, and beef tenderloin as the contenders and steamed them at the same temperature over the course of 40 minutes. Every five minutes, he analyzed the foods’ textures, basically measuring the force needed for someone to chew them. After 40 minutes, the zucchini was soggy and the beef was extremely leathery. The mushroom, however, was still very much edible (via Business Insider).
At the end of the day, the robust construction of mushrooms lets cooks enjoy tender bits, no matter how long they are on top of the stove or in the oven. It’s also good to note that, despite this culinary magic trick, you should still closely monitor your shrooms while cooking them. Leaving any food unattended in the kitchen is dangerous.