Is it good to use a hot pan and cold oil when cooking

Cooking is also a technical job, but it is not as simple as imagined. It is important to pay attention to the cooking method when cooking. Many people say that slow cooking over low heat can prevent the essence of vitamins from being lost, while high-temperature cooking will cause the vitamins in it to be severely destroyed. In fact, this is not the case. When cooking, you must pay attention to choosing the correct method to retain the best nutrients.

"Hot pan, cold oil" and "quick stir-fry over high heat" are the best ways to cook.

Related research shows that when cooking in this way, the vitamin C in the dishes is lost by about 17%, while when the dishes are slow-cooked over low heat, the vitamin C loss is as high as 59%.

First heat the pan, then pour in the oil, and then immediately pour the ingredients into the pan. The oil temperature at this time will not be too high, below 200°C. If the oil temperature is too high, it will cause a series of decomposition and polymerization reactions in the oil, releasing harmful volatile components such as low-level aldehydes and ketones, producing large molecular rings that may cause cancer, and also producing oil smoke.

When ingredients are poured into warm oil, there is an instant buffer when they encounter heat. The cook can use this moment to quickly stir-fry or stir-fry the ingredients. In this way, the protein on the surface of the food will gradually denature, making it easier to stretch and expand, allowing it to be heated more evenly and fully, and the finished product will have a good taste and beautiful shape and color.

When the temperature of the bottom of the pot is high and the oil is relatively cool, the ingredients are put into the oil. As the oil temperature continues to rise, a thrust will be generated, which can make the ingredients float up quickly, making the pot non-stick and preventing the ingredients from breaking.

How to judge the cooking oil temperature?

Judging the oil temperature can be divided into four stages:

Cold oil: The oil temperature is 30℃-60℃, the oil surface is calm, there is almost no smoke, and there is no sound, which is suitable for making fried peanuts, cashews, etc.

Low-temperature oil that is 30% to 40% hot: The oil temperature is 90℃-120℃, the oil surface is white and bubbly, but no smoke is emitted, and there is a slight sound when shaking, which is suitable for marinating meat;

Medium-temperature oil: The oil temperature is 150℃-180℃, the oil surface is swirling, green smoke is rising, and there is a sound when shaking, which is suitable for stir-frying, sautéing, and deep-frying;

High-temperature oil at 70% to 80% heat: the oil temperature is 200℃-240℃, the oil surface turns calm, blue smoke comes out, and there is a sound when shaking, which is suitable for deep-frying and heavy frying.