Milk is pasteurised by first heating it to a temperature of 75 degrees C so that bacteria are killed and then cooling very rapidly so that the flavour of the milk is not spoiled.

Title: To make yoghurt

Apparatus: Large beaker, basin, thermometer, plastic cup, cling film

Method:

1. Sterilise the apparatus by dipping in boiling water.
2. Heat one pint of milk until it reaches 70 degrees C.
3. Cool the milk to 43 degrees C by standing in a basin of water.
4. Add one tablespoon of fresh, plain yoghurt.
5. Transfer the mixture to a plastic cup and cover with cling film.
6. Leave it in a warm place for 6-8 hours until it thickens.
7. Move to refrigerator and leave overnight.