
How is milk ‘skimmed’?
Skimmed milk is whole milk with all the cream removed from it; but how is this process done?
Asked by: Lachezar Yanchev, Stockport
Cream is less dense than water so it floats. In cow’s milk (but not sheep, goat or buffalo milk) proteins cause fat globules to cluster and amplify this process. Milk is centrifuged and the less-dense cream collected from the centre of the drum.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.
Authors

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.
Subscription offer
Subscribe and save 50% on the shop price. Pay just £16.50 every 6 issues by Direct Debit. Receive every issue delivered direct to your door with FREE UK delivery.