I am done paying ridiculous prices at the supermarket for something that can be whipped up in 24 hours and is so much better and cheaper too! This method is the best that I know of, but feel free to use your own method. When you first make the yoghurt you will need a little bought yoghurt, but thereafter you simply use 15ml of the current batch for the new one.
If you want to flavour the yoghurt, it is better to flavour each serving rather than the whole batch.
* 500ml full cream milk - organic (optional)
* 25ml plain yoghurt - organic (optional)
Heat milk in a fairly large saucepan and heat until the boiling milk foams up to the rim of the saucepan. Put milk aside and allow it to cool to bloodheat.
Stir in yoghurt, and pour mixture immediately into a vacuum flask. Close tightly. Leave for 24 hours (no longer than that).
Pour yoghurt into a container with a lid and refrigerate. It will thicken slightly.
And there you have it ...... yoghurt!