Farmer Jimmy Doherty looks at the difference between the milk we buy from the supermarket and milk straight from the cow. He shows how the large fat particles in fresh milk cause the fat to rise to the top but there is no fat layer in supermarket milk. He then uses a pressure washer to pass the fresh milk through small holes to distribute the fat particles. Jimmy then demonstrates the pasteurisation process in his barn.
Ask students to watch the clip with the aim of finding a definition for the words, ‘homogenisation’ and ‘pasteurisation’.
This clip could also generate discussion and encourage further investigation on how much supermarkets influence the foods we eat – does everyone want their milk homogenised? Students may wish to conduct their own form of market research to investigate this question.