The first thing to choose is what kind of yoghurt you want to end up with. Go to the store and try several different brands and you will be able to see the differences in flavour and consistency. This is because there are dozens and dozens of yoghurt cultures, and each one produces a different flavour and thickness of the finished product. So pick the yoghurt you like the flavour and thickness of the best. I used a Greek yoghurt this time but I usually use tillamook because it produces a sweet, mild, and thick yoghurt You can experiment to find the kind you like best.
Now this recipe may seem very unscientific but it's just that I've made it so often that I don't need to look at the book any more. Where I learned it is from my favourite book of all time for all homesteading knowledge. Carla Emery's Encyclopaedia of Country Living
This book will give you all the temps, times, etc that you need for yoghurt making but this is how to do it. I will say that using the mason jars not only seems to produce better more consistent results, but then I just pop them into the fridge for storage.
What you'll need:
Large non reactive saucepan
Large non reactive bowl
Quart sized mason jars
1 Gallon Raw, Store bought, or powdered milk
1 cup plain hopefully organic yoghurt with live cultures
Large crock pot with a warm setting
So how to do it.
Take out your store bought yoghurt and let it come to room temperature first.
Next turn your crock pot to warm and fill half way with hot water from the sink.
Then take your milk and pour it into a non reactive saucepan like stainless steel.. If you are using store bought or dry milk skip the scalding step and just warm the milk. Scald your milk to kill any other bacteria's that you don't want competing with your yogurt culture. Then cool to warm to the touch of a clean pinkie finger.
Next using a wire wisk mix in the yogurt from the store until no chunks are left.
Then pour into a non reactive pan made of glass or stainless steel or your mason jars, cover with Saran wrap, do not use aluminium foil!
Next set the bowl or jars into the crock pot being careful that the water doesn't overflow. If needed add more warm water to the crock pot until its full.
Now just let sit. Try not to agitate the milk and do not stir it. This will mess with the setting process. In about four to six hours, sometimes more, sometimes less, you will see the the milk has magically turned into yoghurt and is thick and solid looking. The longer you let it "cook" the thicker it will become but it will also become more tangy so beware if you like mild yoghurt.
Take it out of the crock pot and put it in the fridge to cool overnight. Next morning enjoy your home-made yoghurt!
I use my home-made yoghurt for tons of things. I use it in place of buttermilk, sour milk, and sour cream in all my baking recipes. It doesn't change a thing in the finished product and is so much cheaper for me to use my own home-made than buying store bought.