Let's start this post with a simple equation.
|In Muskoka after running The Great Muskoka Relay|
A whole lot of long distance running
A very active job for above man
These 2 clowns with hollow legs (true story)
Dump 4 litres of milk into a large pot
Heat slowly until it reaches a temperature of around 180˚ F (or 184 if you are trying to tend to 2 young children, make dinner, make yogurt, and take photos all at the same time)
Turn off the heat and allow the milk to cool to between 110-120˚ F
At this point on turn the oven on to about 200 to get a cozy warm spot for your yogurt to grow. Then whisk in one of these babies. Any plain (or vanilla) yogurt with live cultures in it will due. We had this (no artificial sweetener) vanilla one in the fridge so in this case I used this. The flavour and sweetness is very diluted by the 4L of milk so it does not effect the taste of the final product. You can buy single serving plain yogurts at most grocery stores (I get the Astro Balkan Style one at No Frills), or once you have made one batch you can use a scoop of your own yogurt to culture your new batch (as long as you remember not to eat it all before you make your next batch)
Now TURN OFF your oven, and transfer the mixture into clean, covered glass container(s). Get a nice cozy Thomas blanket, lay it in the oven, place the bowls on top, and pull the blanket over top.
Then grab your Toy Story Snuggie (seriously), and place it in front of the bowls.
Then just for good measure add one more towel. The idea is that you want the inside of the oven and your culturing yogurt to stay warm for 8-12 hours.
Then go to bed and leave the yogurt alone for 8-12 hours.
When you get up your yogurt will look something like this. It will have thickened but will be a bit jelly like, and will have a good bit of whey that needs to be strained off to make the nice thick greek yogurt consistency you are after.
Line a large strainer with paper towel and place inside a large bowl to collect the whey that drains off.
Pour in your yogurt, cover, and refrigerate (or put in your Canadian garage in the winter), for a couple of hours. You can use the whey that is strained off for all sorts of things, it can replace the milk in pancakes, muffins, breads, or you can just pour it down the drain.
Pour into a container, whisk well, and voila!
If you desire you can simmer your milk with a vanilla bean, and even add the seeds for vanilla yogurt. I like to leave ours plain so I can use it in cooking, or we can add whatever we want to it. Fresh fruit, a drizzle of honey, a swirl of natural peanut butter, or a teaspoon of fruit spread are all great options with considerably less sugar then commercial varieties (as long as you do not squeeze the whole honey bear out over your yogurt).