There are few dishes that are made better with leftover ingredients, but fried rice is one of them. Not only is it a great way to use up the odds and ends of leftover vegetables and proteins, it’s actually better to use day-old white rice. In fact, it’s critical.
Unlike freshly cooked rice, which forms soft, mushy clumps when stir-fried, chilled leftover white rice undergoes a process called retrogradation, in which the starch molecules form crystalline structures that make the grains firm enough to withstand the second round of cooking. (It’s the same process that firms up leftover pasta.) That process gives white rice a dry, firm texture that would be disappointing in other rice dishes, but is perfect for fried rice.