This recipe can be used for reaching science key stage 2, attainment target 3:
Materials and their properties 2, changing materials, and 3 separating mixtures of materials.
KS2, AT2/3
Making Yoghurt.
Yoghurt can be made easily on a small scale without the need for sophisticated equipment. It is important to have clean equipment for the making of yoghurt.
You will need:
One pint of Sterilised or UHT Milk.
a saucepan
a tablespoon
a fork
a breadboard
a thermometer (optional).
2 Tablespoons of live Yoghurt.
a thermos flask.
a jug
a basin.
Soft fruit of your choice (Banana, Strawberry or Peach) as flavouring.
Method:
Heat the milk until it reaches blood temperature ( 37° C /98.4° F ) In the jug blend in the 2 tablespoons of with a little of the warm milk, when a smooth mixture is obtained, pour into the rest of the warm milk and stir.  Pour the milk/yoghurt mixture into a pre warmed thermos flask, seal and leave for 7 hours.
Pour the Yoghurt into the basin , and refrigerate for 4 hours to allow the yoghurt to thicken further.
On the breadboard, puree your fruit with the back of a fork, stir into the yoghurt as a flavour.
Yoghurt made this way can be kept in a refrigerator for 4 or 5 days.