Chicken meat is rich in protein, as well as some free amino acids and inosinic acid. They are subjected to high temperatures, which release the meat's characteristic fresh flavor. In ordinary cooking, these fresh flavor substances will inevitably be lost to the soup. Deep-frying, however, locks the gravy containing these flavorful substances into the chicken through the layer of starch paste coated on the surface.
This coating is crucial. It locks in the juices while drying itself out, creating a crispy texture.
During the frying process, water leaks out of the ingredients while oil seeps in. If you put the chicken thighs directly into the hot oil, the surface of the chicken loses water and becomes dry and hard. On the outside, a layer of batter is wrapped around the thighs. The high temperature of the oil causes the starch to paste quickly, and the dissolved molecules of straight-chain starch cross-link to form a gelatin, which then loses water and forms a "crispy skin". This layer of skin becomes a barrier, preventing the inside of the water out, but also prevent the outside of the oil in, which will form a crispy outside and tender inside state.
In addition, the starch caramelizes at high temperatures, and the amino acids and sugar in the batter also undergo a caramelization reaction and a Melad reaction, resulting in a golden color and an attractive aroma.
Taste is one of the most important qualities of meat food. Chicken thighs used in fried chicken are usually modernized "instant chicken". The short production period limits the amount of collagen and elastin in the meat, making it very "tender". For the pursuit of "strong" taste of white chicken and other cooking methods, such tender meat is not satisfactory. But for the pursuit of "crispy" taste of fried chicken, this tender meat is exactly to avoid the shortcomings.
Fried chicken seasoning, and sometimes add chili powder, pepper, garlic powder, onion powder and other spices, so that the chicken this original "mediocre" meat can also have a rich heavy flavor. Why are fast food chicken thighs better than the ones you make yourself?
Frying is one of the traditional cooking techniques. Many people have tried frying their own chicken thighs, but even after reading all the private experiences online, it's still hard to get the crispy, delicious flavor of a fast food restaurant.
The final result of deep-frying is affected by a variety of factors, such as the recipe for the batter, the type of oil, the temperature of the oil, the time of frying, and so on.
Fast food restaurant fried chicken, the choice of each raw material, recipe, operating conditions, have been repeatedly mapped by researchers to optimize, summed up the best parameters, fixed down to strict implementation.
And most of the ordinary eaters, just "according to the cat painting tiger" to imitate the process of other people's fried chicken legs, specific ingredients, batter recipe, oil temperature, time, etc., are quite arbitrary. Our DIY, here a little worse, there a little worse, the final result is far from it.
The starch used in the batter, for example, has a significant effect on the formation of the crispy skin. Starch molecules can be divided into two categories: straight-chain starch is basically a glucose with a glucose, forming a "line"; and branched-chain starch is connected to some glucose on the two, and then continue to connect down, outward, the formation of "branching" structure, and finally formed a large string. Finally, it forms a big string. Most starches contain both types of molecules, but in different proportions. For example, mung bean starch can contain up to 60 percent straight-chain starch, while potato starch contains only about 20 percent.
In general, all else being equal, the higher the amount of straight-chain starch, the crispier the skin. Cornstarch and mung bean starch fry chicken thighs with crisper skin than potato starch breading.
But crispness isn't the only consideration. A batter with a high content of straight-chain starch will adsorb less to the surface of the ingredient, resulting in a crisper but thinner skin that will be less likely to stop water from seeping out and oil from seeping in. In large fast food chains, the starches used are not only carefully selected, but also modified for deep-frying. For example, if the starch is pre-gelatinized, the batter will be easier to coat the ingredients, and the fried chicken thighs will have a thicker skin, absorb less oil, and be more crispy on the outside and tender on the inside.
The effect of oil is also very important. In the process of deep-frying, oil is not just a medium for heat transfer, but the final release of aroma is also closely related to the oxidative cleavage of oil. We will have this life experience: peanut oil and lard fried things more fragrant, and soybean oil fried things to be much inferior. Some people think that "old oil" is better for frying doughnuts, which is not entirely psychological -- oil that has been deep-fried for some time may change its fatty acid composition, and may indeed be more flavorful than fresh oil when it is deep-fried at a particular time.
In the old days, the restaurant industry used hydrogenated vegetable oil in large quantities, with good stability and lower cost being the main reasons, but there was also a reason why the flavor of the things it fried would be better, too.
However, as the trans fats in hydrogenated vegetable oils became a target, food service companies were forced to look for suitable alternatives. Of course, thanks to the efforts of researchers, there are now many acceptable alternatives. Many chefs choose from corn oil, peanut oil, or grapeseed oil.