Yes. You need yogurt to make yogurt. But the thing in that you only need a bit of yogurt. (e.g. 2-3 tsps for 1/2 litre.) So thats why I didn't add the amount of stuff.
BUT the more yogurt you add in, the lesser the waiting time.
LOL, you actually need dried yogurt bacteria to make yogurt, but since I have no clue how lay my hands on them, this works as well. Probably even cheaper, I guess.
You may want to add in the following to your yogurt:
Sugar ------------> Because plain yogurt is so sour!!
Flavourings --------> For the flavour!!
Milk Powder (recommended if you are using low fat milk) ----------> To make it thicker and creamier
P.S. You can make Greek yogurt using this method without a cheesecloth.
(As I'm typing I'm waiting for my No.5 to ferment LOL)
Boil the milk using a double boiler or 'bowl over the pot', stirring occasionally.
You know its done when its 75 degrees celcius
the water in the pot starts boiling and you can see the steam escaping.
Wait for it to cool 'till about 35 degrees celcius OR its slightly cooler than how you want your bowl of soup to be and add in the yogurt
When waiting you can add in yr sugar, milk powder and flavourings. Remember to stir.
Place it into your container checking occasionally, until its the thickness you want it to be.
(It'll take quite a few hours)
DO NOT PUT THE CONTAINER INTO THE FRIDGE.
If making greek yogurt, it'll be ok when there's a layer of liquid floating on top. Scoop out the liquid.
Put it in the fridge till the whole things chilled and you're done! ;D