Many people have done this when stir-frying vegetables: to prevent the pan from burning, they directly add cold water to the sizzling dish.
Regarding this, Yu Renwen, a senior nutritionist at the General Hospital of the Beijing Military Command, told a reporter from the Life Times that this method is not scientific. Because after adding cold water, the temperature in the pot drops suddenly, causing the cooking time of the vegetables to be extended. This not only makes the vegetables older, harder, and worse in texture, but also causes more nutrients to be lost. If water must be added midway through stir-frying, it is recommended to add a small amount of boiling water, so as not to affect the cooking temperature too much, and the stir-fried vegetables will be relatively crisp and tender.
Yu Renwen suggests that it is best not to add water when stir-frying, but to directly place the cut vegetables in the pan to cook, using their own moisture for heat transfer. This way, the dish will be delicious. If you encounter vegetables that are difficult to cook, you can blanch them first. This way, the vegetables will be seven or eight parts cooked, and it will be less likely to burn when stir-fried.
In addition, when making stewed dishes, especially meat stews, you should add enough water from the beginning. If cold water is suddenly added during the stewing process, the temperature of the soup will change abruptly. This will cause the surface of the meat to suddenly contract, making it difficult for the gamey smell to dissipate, the ingredients to absorb flavor, and the umami of the dish will also greatly diminish.