Milk

On the market there are various types of milk that differ in various aspects, for the physical state we find liquid, condensed, concentrated and powdered milk. For the type of treatment there are raw milk, pasteurized, sterilized in the bottle and sterilized UHT (ultra high temperature).

Raw milk means a natural product, as produced by the cow without undergoing any type of reclamation treatment. It is a product with a high bacterial load and its deterioration is very rapid, about 12 hours if not cooled and treated with care. (When I was a child I was lucky enough to be able to drink it as soon as it was milked - I am of peasant origins - but times have changed and for the safety of people's health it is no longer on the market in its pure state.
By cooled milk we mean a product subjected to remediation treatments that partially or totally destroy the bacterial load in order to ensure a longer life and better hygienic safety. So we have pasteurized milk and sterilized milk.
The pasteurized milk with special equipment is brought to 75 degrees centigrade for a few seconds and immediately brought back to 4 degrees centigrade. This serves to destroy pathogenic germs and a large part of the bacterial load to make it safer for consumption. The partial but not total decrease of the bacterial load still allows a longer shelf life, but only up to a maximum of three days. The remaining bacterial components multiply rapidly leading to deterioration of the product. Opinions on boiling before consumption are divided.
Sterilized milk is also subjected to heat treatment but at higher temperatures which completely destroy pathogens and other bacterial components. We find the sterilized milk in the bottle where the heat treatment is carried out before and after bottling at a temperature of 125º for about half an hour. The product becomes non-perishable but partly depleted of vitamins and proteins in its organoleptic component. The consumption of this milk has been largely supplanted by U.H.T.
UHT sterilized milk known as long-life is certainly the most used today, it shares the advantages of avoiding the defects of pasteurized milk and sterilized in the bottle. It is treated with a rapid thermal excursion for a few seconds at 140º, immediately cooled and packaged with an aseptic system in containers made of paper, polythene and aluminum (tetra brik).
Based on the content of fat content, we find whole, skimmed and partially skimmed milk. Whole milk, sterilized as it is from the production of cows with fat content from 3% to 3.8% depending on the breed of animals, the season and their diet. By law it must be 3.2% minimum. Recommended for children and adolescents for its high contribution of calories and for those who carry out intense physical activity. Partially skimmed milk is determined that which has been subtracted about half of the fat present. Suitable for those who carry out sedentary activities. Skimmed milk is almost totally deprived of the fat part which is reduced to less than 0.5%. It is suitable for those who follow low-fat diets but is the most pleasant as a drink due to its digestibility. However, even partially or totally skimmed milk, lower in fat, always remains rich in proteins, salts, sugars and vitamins.
For the work of the bar it is however advisable to use whole milk for the type of yield in the various preparations (cappuccino etc.)
The milk cream is also very important for the work of the bar, it enters in many preparations, in normal drinks as in cocktails. Natural for various drinks and whipped for other drinks such as chocolate etc. Once opened, the carton must be consumed in no more than two days and kept in the refrigerator; to be calm, at the end of my working day in the bar, I throw away what is left over and the next day I use another fresh one. Believe me, I don't throw money away but I gain peace of mind in my work and customers perceive it and feel relaxed asking for preparations with ingredients that are so delicate for their health.
For more info on milk visit

http://it.wikipedia.org/wiki/Latte