Puffing milk. This is what we call milk, in which gases are produced, or even before souring, or when it turns sour. Fermentation is more or less abundant, sometimes so alive, that the clot is saturated with gases, torn or even thrown over the edges of the pan. It is usually caused by coli-aerogenes, less often yeasts or butyric acid bacteria. As we already know, coli-aerogenes live in the intestines and faeces of animals, where they get into milk, especially in summer, when heat creates favorable conditions for development. Bloating milk is most often produced in the following cases.
1. After a sudden feed change, e.g.. during the transition from dry to green forage. As a result of feeding on a young clover, an excessive amount of beetroot leaves, a young horse's tooth, decoctions. Then there are disorders of the digestive organs and diarrhea, which should be prevented by adding the right amount of hay.
2. Due to inadequate feed, like hot grass, rotten mixtures, moldy feed, spoiled karma.
3. With chronic catarrh of the digestive organs.
4. Due to contamination of milk vessels, strainer, cloths, etc..
5. After inadequate supply of meadows with artificial fertilizers and pouring liquid manure on meadows during the vegetation period of the grasses.
When we notice smokey milk in the cheese factory, we should investigate immediately, which barn it comes from and remove it from processing into cheese, until the defect persists, or at least carefully pasteurize. A small amount of more or less puffing milk will always get into the cheese dairy without being noticed, but it's not dangerous, when most of the milk is healthy. Sigh milk is used to make poor cheeses.
This is what characterizes cheese milk, that it usually solidifies after a few hours. The clot is sweet or sour. The curd made from it is cohesive and similar to rennet casein. This fermentation, called rennet, is usually caused by acid-rennet cocci. The defect occurs most often in hot weather and is generally not too serious for rennet cheeses, if it appears only in part of the milk and after 12 do 24 hours. On the other hand, when making cottage cheese, it can be felt, because we are not getting the correct curd here. In this case, pasteurization and the use of leaven are recommended.
Perishable milk. In this case, the measure in the assessment should be different depending on this, what purposes the milk is used for and what kind of infection is it. After all, it is difficult to call milk defective, if it contains at least a significant amount, but almost exclusively beneficial lactic acid bacteria. We then have a natural course of fermentation as to the direction. There is only a question, whether there are too many bacteria, as a result, there may be reservations as to the time the milk becomes sour. From the cheese stand, the milk is also considered defective, which does not stand in sweet unaltered state 12 hour standstill, even if it has the correct bacterial composition. It is the issue of producing milk containing much less 100 000 bacteria in 1 cm3.
Ductile and mucilaginous milk. Different bacteria make the milk mucilaginous; Even lactic acid bacteria do so under certain conditions. The defect usually disappears after thorough disinfection of the dishes and changing the rinsing water. Ductile milk can be processed without harm, as long as the cheeses are dripping well.
Bitter milk. The bitter taste of milk is caused by peptonising bacteria in addition to the feed (hay, potato and others). This disadvantage is also caused by microorganisms that are relatively rare in milk (Torula amara, Str. bitter house). Bitterness is stronger in cream than in milk. Rusty dishes also taste astringent and bitter, because lactic acid forms with iron lactates of iron with this taste. This is still associated with the discoloration of the cheese due to the presence of iron.
Milk with beetroot and carpel flavor. As a result of giving the cows an excessive amount of beetroot leaves, carp, in general, forage containing harsh substances characteristic of cruciferous plants, the milk acquires the taste and smell of these feeds, especially if they are broken and cause disorders of the digestive organs. This defect is caused to a lesser extent by substances, which pass from these feeds into the milk rather than as a result of the activity of the bacteria, which are on these feeds and then directly, or with the faeces they get into the milk. The beetroot smell is caused by e.g.. some varieties of cola even then, when cattle are not fed beetroot. The defect is removed after the cows have healed from diarrhea, which requires limiting the amount of beets, etc.. feed.
The soapy-flavored milk is most often caused by bacteria, which produce ammonia. They unfold in the cold. Sour cream affected by this defect foams when churning, which lasts a long time, before butter lumps form. Avoid keeping the milk cool for too long in the absence of lactic acid bacteria.
Milk with a pungent smell . When fresh, still warm, unventilated and uncooled milk is stored in tightly closed watering cans, then it acquires a sharp, like, prickly smell. The actual cause of this is not yet sufficiently understood, possibly associated with the development of anaerobic bacteria. Ventilated and chilled milk can be tightly closed in watering cans without any harm and stored for some time.. Milk with a pungent smell is not suitable for making cheese.
Colored milk. Some bacteria and yeasts stain the milk, especially the older ones, in yellow, pink, red or blue. This defect is rare. Disinfection of dishes removes it. Do not use too old milk.
Milk with a tallow and oily flavor. Tallow flavor, especially outstanding in cream, occurs due to the action of sunlight on fat. It is also caused by some lactic acid bacteria growing at temperatures around 10 ° C and rusty dishes.
Preserved milk (preserved). In cheese making you have to, declare any milk preserved chemically unfit for processing, also pasteurized or cooked before delivery to the cheese dairy.
Milk contaminated with pathogenic microorganisms. Bacteria that cause infectious diseases, like abdominal typhus, damn it, scarlet fever, dysentery and others can easily be transferred to the milk and spread this way. Milk from houses with infectious diseases can be consumed after boiling, but not processed in the cheese factory. It is best not to take it outside the production site.