Milk has been present throughout time in the human diet, despite the fact that in recent years its consumption has been replaced by other beverages of vegetable origin. It contains a great contribution of proteins of biological value, as well as nutrients such as calcium or phosphorus. But one of the biggest doubts about this food is how to keep it and how long it lasts once the tetrabrick or the bottle in which it is packaged is opened.
The Organization of Consumers and Users (OCU) has published a guide in which it gives a series of recommendations on the conservation of milk. It is a food full of nutrients and, therefore, it is the ideal breeding ground for the development of microorganisms that can spoil it.
The milks that can be found in commercial chains are distributed with all the hygienic guarantees so that they can last without spoiling during their useful life. As a general rule, fresh or pasteurized milk with traditional treatment can be stored cold for three or four days, while highly pasteurized milk can be kept for up to fifteen days. That as long as we have not manipulated the packaging.
As for UHT (uperized) milk, it can be stored at room temperature for between three and six months, and sterilized milk can reach nine months under the same conditions.
Although it is not very common, it can sometimes be the case that a closed container is swollen. This is usually caused by a problem during packaging: a pore is created that allows the growth of gas-generating microorganisms, such as yeasts. In this case, as it is a closed container, it is best to take it to the store so that they can change it.
However, the problem appears when we leave an open container in the fridge, either because we don't consume too much milk or because we forget about it. That is why it is important to know how long we can consume that product once opened.
Pasteurized milk receives a light treatment that destroys pathogenic bacteria, but it is not sterilized in any case. For this reason, it should be consumed in two or three days at most. As regards UHT and sterilized milk, despite the fact that it has received a more severe sterilization treatment, we should not consume it if it has been in the fridge for more than five days.
If we look at other types of milk, such as evaporated milk, for example, by undergoing a sterilization heat treatment it makes it possible for us to keep it in a closed container outside the fridge and it can last up to a week. On the other hand, condensed milk, as it contains sugar, can be kept in the fridge longer than other milks, up to two weeks if it is well covered.
To find out if a milk is in bad condition, the OCU recommends pouring it into a transparent glass and looking at its condition. If the fat separates and floats, if there are white dots sticking to the surface of the glass, or if it appears cut, it should be discarded. Another indicator can be the intense smell or, as a last resort, we can try it and see if its flavor is the same as always.
