Caption

Milk bottles. View of three types of bottled milk. At upper left is semi-skimmed milk, with a red and silver top. This milk has had the majority of its fat removed before bottling. At centre is gold-top milk, which has full fat. Cream is seen at the top of the bottle as the yellowish band. At right is silver-top milk, which is intermediate between the two. Milk has the fat removed to make it more healthy to drink. It is also pasteurised to kill any micro-organisms living in it. This process involves raising the milk's temperature to 64 degrees Celsius or more for a standard length of time. Milk is rich in the essential mineral calcium, and also contains protein and vitamins.