How to determine the fat content of milk at home: measurement methods

The quality of dairy products obtained from their own livestock is important for farmers who receive them for the purpose of sale. Therefore, the question of how to determine the fat content of cow's milk at home is very relevant. It is easier for livestock breeders with large herds to invest in the purchase of a special apparatus for determining fat content. Housewives who raise only a few cows can use simple improvised measurement methods.

What is the fat content of cow's milk

The amount of fat contained in milk is most often measured on a relative scale, that is, as a percentage of the total mass of the product.For example, an indicator of 3.2% means that there is 3.2 grams of fat in 100 grams of milk. In mass production, the concept of total fat content (in weight units) is used.

Fresh milk is the leader in fat content, if stored at a temperature not higher than +7 ^{оС and no longer than a few hours, after the fats are broken down into other compounds. Milk from the Kholmogorsk, Kostroma and Sychevsk breeds of cattle is considered the fattest - the percentage of fat in it ranges from 3.2% to 4.5%, and in Yaroslavl cows - almost 6.0%.}

The following factors can affect the fat content of milk:

• cow breed;
• features of keeping - more fat milk from cattle, spending most of their time on free grazing;
• feeding ration;
• age - milk reaches its maximum fat content in cows by 5-6 calving.

In the summer, cows eat more fresh grass and drink plenty of fluids. Therefore, in winter, milk becomes much fatter. The average fat content of cow's milk is 3.2-4.5%.

Measurements

To check the fat content of milk immediately after milking, farmers who keep large herds of cattle often purchase a special device - a butyrometer. Such devices are indispensable on large livestock farms that sell milk. The product, in which it is necessary to find out the percentage of fat content, should not contain impurities and additives, peroxide and starch, which prolong the shelf life of milk.

With the help of a butyrometer, you can determine the level of fat from 0 to 6%. The device looks like an oblong tube, consisting of narrow and wide parts. Once the milk sample is placed in the device, it will need to be heated and separated to separate the components of the product.

How to use the butyrometer:

• milk is poured into the tube;
• added obligatory component for determination of fat content - concentrated sulfuric acid. Thanks to the substance, a reaction begins that separates the product into fatty and whey parts. A clear boundary is formed at the interface between two media;
• Isoamyl alcohol is poured in.

The butyrometer must be closed so that during the measurement procedure milk does not leak out of it, stain the surfaces of the laboratory and staff clothes, and the loss of the product does not affect the results of the study.

The device is placed in a water bath, which is purchased with a butyrometer, and heated to 65-70 ^oC.

It is important to control the heating temperature with a thermometer so as not to spoil the product and not get a false result.After that, the butyrometer is placed in a centrifuge, where, as a result of exposure to milk at 1000 rpm, it is separated into fat and whey. The result (fat percentage) is determined by the butyrometer scale.

Determination of fat content at home

To find out the fat content of milk yourself, you need to prepare a fresh sample of the product and a clean glass, the walls of which are strictly vertical. At a height of 10 centimeters from the bottom of the dish, a mark is made with a marker. Milk must be poured into a glass to the drawn line. If it has settled, shake it up.

The bowl of milk should be left for 6-8 hours, and then evaluate the result. Cream will be at the very top, and a more liquid product will be located at the bottom. The thickness of the creamy layer is measured with a regular ruler - from the top of the liquid to the border with the bottom (liquid) milk.

The percentage of fat content is calculated as follows: the thickness of the cream in centimeters is divided by 10 centimeters, the result is multiplied by 100%.

A more complex measurement method requires accurate scales. On the outer surface of the container, in which the settled product was located for several hours in a row, the border of cream and milk is marked. After the liquid can be poured into another vessel. With the help of scales, the mass of water, which is then filled with a milk jar, is determined to the bottom mark and the volume of water between the marker stripes. To do this, the container (jar) itself is initially weighed, then the liquid between the marks is poured and weighed, and then the rest.

Next, simple calculations are carried out: the weight of the liquid obtained between the marker lines must be divided by the total mass of water. The resulting figure must be multiplied by 100% - this will be the fat content of milk cream. After you need to measure the percentage of fat content of milk. With a fat content of cream, for example, 15%, the coefficient will become equal to 0.25.In the case when the volume of the creamy mass is greater by 1% or 2%, add to the coefficient 0.01 or 0.02, respectively. If the mass of cream is less, subtract from the coefficient.

It can be determined by an example: it turned out that 300 grams of milk accounted for 48 grams of cream. It is necessary to calculate the percentage of cream: 48/300100% \u003d 16. The coefficient of standard creamy fat content is 0.25 (at 15%), 0.01 should be added to it, it turns out 0.26. Then you need to calculate the concentration of milk: 16%0.26=4.16%.

What can affect the final fat content

It is important to consider that the percentage of dairy products can be increased under several conditions:

• the most liquid are the first streams of milk milked from the udder. They contain only 1% fat;
• the thickest is the last (hind) milk;
• Fattier and thicker milk from cows fed a balanced diet during the dry period - if the farmer prepares feed fortified with vitamins, minerals, proteins, fats and carbohydrates for cattle.

Depending on the breed, the milk will also be more or less fat. Usually cows that give less milk will have more concentrated milk and vice versa.

During the whole summer period, cows are grazed on pastures, so the milk acquires not only natural concentration, but also positive taste qualities, as well as a pleasant creamy shade. In winter, to maintain fat content at the proper level, cattle must be fed in a balanced way - give hay, grass meal, silage, vegetables, cereals with boiled root crops and vegetables.

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