Classic technical essentials of kitchen-what is thickening? With the help of starch, it has the characteristics of water absorption, adhesion and smoothness. When the dishes are close to maturity, pour the prepared powder juice into the pot to thicken the marinade and increase the adhesion of the marinade to the raw materials, thus increasing the powder and concentration of the soup and improving the color and taste of the dishes. Starch used for thickening, also known as dough powder, is a polysaccharide polymer concentrated by multiple glucose molecules. Starch used for cooking mainly includes mung bean starch, potato starch, wheat starch, water chestnut starch and lotus root starch. Starch is insoluble in water. When it is heated to 60℃ with water, it will be gelatinized into a colloidal solution. Thickening is the use of this property of starch. Mung bean starch is the best starch and seldom used. It is made by grinding mung beans and precipitating with water. It is characterized by sufficient viscosity, small water absorption and white and bright color. At present, potato starch is widely used in families. It is made of potatoes through grinding, cleaning and precipitation. It is characterized by sticky feet, fine texture, white color, better luster than mung bean starch, but poor water absorption. Wheat starch is precipitated from wheat bran washed with gluten or wheat bran made of flour, which is characterized by white color, poor luster, inferior quality to potato flour and easy precipitation after thickening. Sweet potato starch is characterized by strong water absorption, but poor viscosity and dark red and black color. It is made of fresh potatoes through grinding, scrubbing and precipitation. In addition, there are corn starch, water chestnut, lotus root starch, water chestnut starch and so on. Whether thickening is appropriate or not has a great influence on the quality of dishes, so thickening is one of the basic skills of cooking. Thickening is mostly used in cooking techniques such as frying, sliding and frying. What these cooking methods have in common is the rapid development of fire, and the dishes made in this way basically contain no soup. However, due to the addition of some seasonings and the moisture of raw materials, the soup in the dish is increased. By thickening, the juice is sticky and attached to the surface of raw materials, thus achieving the luster, smoothness and deliciousness of dishes. There are usually two kinds of thickeners. One is starch juice with seasoning, commonly known as "juice-to-juice", which is mostly used for dishes cooked by quick frying and stir-frying. One is simple starch juice, also called "wet starch", which is mostly used in general cooking. Pouring juice is also a kind of thickening, also known as thin thickening and glaze thickening, which is mostly used for stewing, roasting, roasting and soup dishes. According to the cooking methods and characteristics of dishes, the usage of sauces is basically as follows: 1. Usually use the method of stir-frying to cook. The powder juice is the thickest, and the purpose is to spread the sauce all over the raw materials, such as fish-flavored shredded pork and fried kidney flower. After eating, there is basically no marinade at the bottom of the dish. 2. Paste is generally used for cooking dishes such as stir-frying, sliding, stewing and stewing. Powder juice is thinner than bread, which is used to turn the soup of vegetables into paste, realize the fusion of soup and vegetables, and have a smooth taste, such as sweet and sour pork ribs. 3. Dried glutinous rice paste juice is thin, generally used for large or whole dishes, which is used to increase the taste and luster of dishes. Generally, after the dish is served, the marinade in the pot is heated and thickened, and then poured on the dish, some of which are stained with colored glass, and some juice can be left on the plate after eating. 4. Milk soup is the thinnest sauce, also called thin sauce. Generally used for stews, such as spicy tofu, shrimp and crispy rice. The purpose is to thicken the soup of dishes to meet the requirements of fresh color, fragrance and taste. If you want to thicken well, you need to master several key issues. First, to master the thickening time, it is usually when the dish is ripe. Thickening the sauce too early will scorch the marinade, and thickening it too late will easily make the dishes heated for a long time and lose their crisp and tender taste. Second, the thickened dishes should not use too much oil, otherwise the marinade will not stick to the raw materials easily, and the purpose of adding umami flavor and beauty will not be achieved; Third, the soup should be appropriate. Too much or too little soup will cause the sauce to be too thin or too thick, thus affecting the quality of the dishes; Fourth, when using pure flour juice to thicken, you must first adjust the taste and color of the dish, and then pour in wet starch to thicken it, so as to ensure the delicious taste and bright color of the dish. Starch has strong hygroscopicity and peculiar smell absorption, so it should be well preserved, moisture-proof, mildew-proof and odor-proof. General room temperature 15C, humidity below 70%. When cooking, another requirement is to thicken the oil, that is, after cooking, pour in all kinds of seasoning oil to make it dissolve or adhere to the thick stuff. It has the functions of enhancing fragrance, refreshing, coloring and brightening dishes. When using, the two should be combined well. According to the taste and color requirements of dishes, pour in different colors of edible oil, such as chicken oil (yellow), Chili oil (red), tomato oil, sesame oil, pepper oil and so on. Pay attention to oiling, and be sure to pour it after cooking, so that it will be bright and shiny. Don't refuel too much and too fast at a time, or it will leak oil. Because cooking methods are different, there are different ways to refuel. Generally, cooking and cooking are cooked and then poured with bright oil on the spoon. Dry cooking, the dish is to take out the spoon, pour the remaining juice in the spoon into the oil and pour it on the dish. After Ming oil is added to the sauce, it should not be stirred too fast to avoid oil analysis.