5. Pasteurisation The next step is pasteurisation, which allows milk to stay fresh longer. Using the High Temperature Short Time method, the milk is heated to not less than 72˚C for no less than 15 seconds. This kills any potentially harmful bacteria and extends the shelf life of the milk. The milk is then rapidly cooled to 4˚C.
6. Homogenisation All milk is homogenised, to prevent the cream separating and settling on top. During the homogenisation process, the milk is forced through tiny holes at high pressure which breaks up the fat globules (cream) into tiny particles. This results in the cream spreading throughout the milk in a permanent suspension.
7. Packaging Milk is then sent through a processing line to be packaged in cartons or bottles. Once the correct amount of milk has been put in, the carton is heat sealed, stamped with the ‘use by date’ and packaged in milk crates.
8. Distribution Every day, milk is distributed from the factory to various milk depots in refrigerated trucks.
UHT or ultra heat treated milk is a form of milk that has been heated to a temperature of at least 135ºC in order to kill off any harmful micro-organisms (e.g. harmful bacteria) which may be present in the milk. The milk is then packaged into sterile containers.
UHT milk is available in whole, semi skimmed and skimmed varieties.