Butter is a kind of solid oil processed from milk, which is the product of filtering some water from the upper layer of thick matter after mixing fresh milk. Mainly used as seasoning, rich in nutrition but high in fat, don't overdo it.
Butter will slowly and naturally soften at room temperature, and 15 degrees Celsius will soften. The higher the temperature, the faster the softening and deterioration. When the room temperature is about 20℃, it will go bad after 2-3 days, so butter is easy to go bad when stored at room temperature. The refrigerator is different. When refrigerated at 2-8℃, it can be stored for 6- 12 months. Frozen below 0℃, it can be stored for 12- 18 months.
The formation of butter
Like butter, the oil content of margarine should not be less than 80%. Because the oil content of natural oil is almost 100%, it is necessary to add water (usually milk or light cream) to form a water-oil emulsion that meets the requirements, and its physical properties are basically the same as butter. Soybean oil and cottonseed oil can reach ideal consistency after refining and partial hydrogenation, so they are widely used in the production of margarine.
In the production of margarine, two kinds of mixtures are usually made first: one is oil and all fat-soluble additives, and the other is water and all water-soluble additives. Then, the two kinds of mixture are put into a tank, stirred vigorously and emulsified, so that water is evenly dispersed in the oil in the form of small drops. Subsequently, the turbidity is cooled quickly, because if it is not cooled to make it hard, the turbidity will be separated quickly. Modern continuous cooling system pumps turbidity into a series of heat exchangers, and some special agitators can be installed in the exchangers to further reduce water droplets and disperse them in gradually hardened grease.
Then, the turbidity passes through a cooled crystallizer to further solidify and plasticize the fat. Proper temperature control is extremely important if cleavage semi-plastic structure is to be produced. Finally, semi-solid margarine can be continuously extruded into blocks by an extruder and packaged.
Although butter can only contain butter grease, margarine is not so strict, and margarine can use any grease. Some margarine made of vegetable oil can be added with 5 ~ 10% butter to improve the taste.
Butter and margarine have a very close structure. In order to improve its spreadability and reduce the heat content, whipped cream and whipped margarine were produced. This is to pump air and nitrogen into the product to increase its volume by about 50%.
The principle of butter beating is that solid oil can be wrapped by air during beating, similar to egg beating. In the process of constant beating, the volume of butter becomes more and more thick, and the inside is covered with countless tiny pores. When butter is mixed with other materials, it can act as a leavening agent in the baking process, making cakes/biscuits bigger and looser.