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.


The same method can be used using dilute evaporated milk, a richer product can be made by adding dried whole milk powder or cream.

Yoghurt made in this way can be further processed into a soft cheese.


For this you will need:a colander
a washing up bowl
some cheese cloth or muslin
fresh chives or other herbs to flavour the cheese with

Method

Place the cheese cloth in the colander, place the colander in the washing up bowl, pour in the yoghurt and allow to drain ( this may take some time )


Take the corners of the cheese cloth and tie tightly with string, hang up over the washing up bowl and allow to drain for a further hour.


The finished cheese maybe flavoured with chopped chives or other fresh herbs.