MILK PROCESSING AT HOME CONDITIONS.
Milk cleaning aims to remove visible mechanical impurities (particles of feed, litter, wool, etc.) by filtering the milk when draining. As a strainer, you can use cotton filters, flannel, cheesecloth folded in three or four layers, nets made of synthetic fabrics (lavsan, nylon, etc.). Milk cleaning is more convenient to carry out using a special sieve - strainer.
Cooling... In order to preserve milk, it should be cooled as soon as possible after milking. At home, in summer, milk is cooled in glaciers or cellars using prepared ice, as well as in cold water (well, spring).
The best way to preserve milk is to refrigerate it in your home refrigerator. Milk chilled to + 10 ° C can be stored for up to 24 hours, and at + 5 ° C for up to 36 hours.
Freezing.
For long-term storage in the winter, as well as in the presence of low-temperature refrigerators, milk can be frozen. To preserve the structure of the milk, the layering method is recommended for freezing. Milk is poured into special dishes (baking sheets) with a layer of 2-3 cm, after it freezes, a new layer is poured, etc. Frozen milk is stored at low temperatures.
Pasteurization... The main changes in milk after milking occur under the influence of microflora, which causes its sourness and the appearance of various defects that are dangerous to human health. Compliance with sanitary and hygienic rules for obtaining milk significantly reduces its bacterial contamination.
To combat microflora, milk is neutralized using high temperature (pasteurization, boiling, sterilization). Pasteurization destroys 99% of microorganisms, with the exception of spores, boiling - part of the spores, and sterilization - all spores.
When heated, the gases dissolved in it evaporate from milk, proteins (albumin and globulins) coagulate and precipitate, enzymes are destroyed, some of the mineral salts precipitate, etc. Heating to a temperature of 80 ° C and above gives milk a special taste and aroma ... When boiling, these changes intensify, valuable substances are lost within 15-20%, therefore there is no need to boil milk, especially pasteurized milk, without special need.
At home, milk can be subjected to long-term pasteurization at a temperature of 63-65 ° C for 20-30 minutes, and then cooled. For the purpose of pasteurization, it is better to place milk in water preheated to a boil. With this mode of pasteurization in milk, there are minimal changes in quality. Milk can be pasteurized by heating up to 72-74 ° C with exposure for 30-60 s or up to 85-87 ° C without exposure. In case of contamination of pasteurized (boiled) milk again by microflora, it deteriorates faster than raw milk and becomes bitter.
Preparing baked milk. Boil the milk, pour it into a lined earthenware dish or cast iron and put in an oven or oven for 1.5-2 hours. The resulting froths from fat and proteins should be periodically immersed in milk. When the milk acquires the appropriate creamy color, the heating process is stopped, then the milk is cooled.
Separation... Milk is subjected to separation to obtain cream of any fat content. For home processing of milk, the industry produces small separators with a capacity of 30 to 100 liters per hour with a manual electric drive (Saturn, Volga, Ural, Plava, etc.). It is recommended to install them in a heated room on the edge of a stable table or on a special stand vertically without distortions (using a plumb line and level). The assembly, disassembly and maintenance of the separator is carried out in accordance with the instructions supplied by the manufacturer upon sale.
Separate strained and fresh milk, preferably fresh milk; cold milk must be heated to 30-35 ° C. Pasteurized or boiled milk is processed much worse, there are large fat losses. Gauze (in 2-3 layers) or other acceptable (lavsan, nylon) fabric is preliminarily tied to the separator receiver, through which milk is filtered during its filling. Then slowly and smoothly, gradually increasing the speed, rotate the handle of the separator to 60-65 rpm. The electrically driven separator is connected to the network. When it reaches the required number of revolutions (they will know about this by stopping the signaling by the bell), the receiver tap is opened, and the milk begins to pass into the drum for separation. To keep the process continuous, milk is periodically poured into the receiver. The fat content of the cream is adjusted by turning the cream screw with a square hole. When turned to the right, it is screwed in and the fat content of the cream increases, and vice versa.
At the end of separation, up to 1 liter of skim milk (skim milk) is poured into the receiver and, without turning (or turning off) the apparatus, wait until the return flows from the cream cone. This means that all the milk fat has been removed from the drum and the tap on the receiver must be turned off. After skimming the milk, the dishes and the separator drum are disassembled, washed with cold water, warm soda solution (0.5%) and clean water. Separator parts are laid out on the table to dry. The rubber ring is washed in clean water and dried.The plastic parts of the separator cannot be stored at subzero temperatures, they become brittle, in order to avoid darkening, it is not recommended to dry them near a stove or in bright sunlight.
Milk is not sufficiently separated (skimmed) if it has a low temperature or is poorly cleaned of mechanical impurities, as well as if the drum is not assembled correctly, its nut is loosely tightened or it is low set (the cream partially gets into the return), the drain screw is not adjusted or its hole is clogged ...
Milk or return flows out of the separator in case of poor fastening of the drum nut, damage to the rubber ring, low fit of the drum (return falls under the horn), incorrect installation of the ring, float or blockage of the float chamber tube. The separator trembles, and extraneous noises appear in it if it is poorly fixed on the table, when the rotation transmission system is worn out.
The performance of the separator decreases when the tube of the float chamber is clogged, when the receiver valve is not opened sufficiently, when milk is acidified (spaces between the plates are clogged), and lubricating oil is contaminated.
Home pantry
Comp. V. Dontsov, V. Baklanov, V. Brodov, N. Mikhailov. -
Moscow: Sunday, 1992 .-- 432 p.