As soon as the Thermometer reads 49 degrees  C,  I rapidly take the jug out of the cooling water and to the stove.

Gently take the pan with the glass jars out of the oven, (closing the oven door immediately). Divide the milk evenly over the four jars and stir the starter through.

I sometimes cover the milk with circles of baking parchment to stop a skin forming and to distinguish between different types of culture. This is not really necessary.

Put the jars in the pan gently back into the oven.  This part of the sequence must be done swiftly to prevent the temperature of the milk falling too low.

Come back after 8 1/2 hours and take out the pan carefully, without jostling. It will look identical to when it went in. A gentle tap on the surface will reassure you that it is in fact beautifully set.

Very very gently remove the yoghurt one jar at a time from the pan to the fridge. This is where you can do most damage to the consistence of the yoghurt.

It needs 8 hours minimum in the fridge. This will set it further and make it even more delicious to eat.

When you take the parchment paper off, the surface looks a little lumpy. This is not so and a deft stroke of a spoon will reveal the beautifully smooth texture.

Once you break the surface tension, the yoghurt will start 'to leak'. This is quite normal in commercial yoghurt as well. It has to do with the amount of lactose which has been converted into lactic acid. You can either eat the entire jar at once (my recommendation) or pour off the liquid when next opening the jar.

The liquid is actually quite nice to drink with a straw.

There are various ways to firm up the yoghurt even further. One is to extend the growing period in the oven to anything up to 24 hours. Or you can copy the Greek yoghurt technique and once set and cooled, let if drip through a straining cloth in a sieve or colander.

This is particularly effective when using full cream milk.