Self-heating rice is a fast food, which can be directly heated without electricity. So, what is the heating principle of self-heating instant rice? Self-heating rice has a heating bag, which contains coke powder, activated carbon, salt, quicklime and other substances. The temperature rises within 3-5 seconds after meeting water, and the temperature can be as high as 150℃, the steam temperature can be as high as 200℃, and the heat preservation time can be as long as 3 hours, so it is easy to make raw rice into cooked rice.