NOTE: (NEVER buy light yogurt - that just means they loaded it with cancer causing Splenda or aspartame.)
So after some trial and much error, I finally came up with a recipe/method that works for me. It is really quite easy and rewarding.
1. Pour 4 cups of milk into a pot, heat over medium heat stirring occasionally until you thermometer reads 185 degrees.
2. Pour into a bowl to cool. It needs to cool to 130 degrees before you can do anything to it.
3. Once the milk is just under 130 degrees, whisk 1/2 cup of powdered milk and 2 tablespoons of store bought yogurt. After you make a batch, always save a little to be the starter for your next batch. That way you will never have to buy it.
Do not even try to stir it with a spoon, you will not be successful and later when pouring the mixture into cups you'll find lumps.
4. Now, I know you will be tempted, but DON'T try to sweeten or flavor the yogurt now. You must wait until right before you eat it to do so. I have tried several times to add sugar now and it only results on runny yogurt that doesn't set up properly.
5. Pour the liquid-soon-to-be-yogurt into your yogurt maker's cups. I know that not everyone has a yogurt maker and neither did I a few months ago but now I have two. I found them both at different Savers for under $5 and they are the same exact model. If you are serious about making yogurt I'd say they are the easiest way to go.
6. Lastly, pop on the lids, plug in your maker (which I found keeps the yogurt barely warm) and let it sit for 12 hours. I usually do all this at night so in the morning the yogurt is ready.
7. Put the yogurt jars in the fridge until you want to eat it. Here are some ways that Claire and I like to flavor our yogurt. I'm sure there are a hundred ways to flavor it, these are just the things I have tried.
a) add honey to taste
b) add sugar to taste
c) add sugar and your favorite flavor of jam
d) add sugar and vanilla
Having all that plain yogurt on hand also comes in handy for baking, or we like to add sugar to it and use it instead of milk on our cereal.
Delicious! We will never buy yogurt again!