This is a picture of today's yogurt disaster. I have made yogurt many times, but only twice in this oven. And I AM SO FRUSTRATED WITH MY OVEN!!! I really need to invest in an oven thermometer, because it is always WAAAY too hot. Anyway, apparently it got so hot today that it melted the containers I was making yogurt in.

So.

I guess I get to make yogurt again tomorrow! (Lesson learned: I now use glass jars to make my yogurt in.)

Anyway, if anyone out there would like to try giving homemade yogurt a try, here's my recipe. It's really easy--hands-on time is only about 10-15 minutes, most of which is just waiting for your milk to heat to the proper temperature. Way cheaper than buying it all, too, especially if your family likes yogurt as much as mine does.

Oven Yogurt

Makes 4 quarts (4 L)

2 c. (125 mL) good quality commercial plain yogurt with live cultures, or 1/2 cup yogurt from previous batch (In Canada, Astro Balkan-Style yogurt is the best I've found.)
1 gall. (4L) pasteurized whole milk, (nonhomogenized is best, if you can find it.)
a candy thermometer (I just use a pocket thermometer)
10 pint (500 ml) glass wide-mouth mason jars

1. Preheat the oven to the lowest temperature you can get it. For most ovens, this is around 170 degrees F. I heat it up to this while I am prepping the yogurt, then immediately turn it off. Once the yogurt goes in, the oven doesn't get opened until it's done, but it won't need to be turned on again. The yogurt maintains a good temperature because of the action of the culture.
2. Pour milk into a large pot. Gently heat the milk to 80 degrees C/180 degrees F, stirring often so it doesn't stick to the bottom. Cool quickly to 42 degrees C/110 degrees by placing pot in sink of ice-water. (I usually take it out when it gets down to 120 degrees because it will cool the last bit when you add the cold yogurt.)
3. Stir in yogurt and place in small, clean glass, enamel, or stainless steel containers. (I find anything bigger than a 750 mL /24 oz container doesn't work as nicely. Or, you could place in a shallow glass, enamel, or stainless steel container. I now use pint jars to make this in, and find it works great. Wipe the threads before you seal them if you spill.)
4. Cover the container and place in a warm oven (110-150 degrees, but no warmer, or a gas oven with a pilot light. You can check your oven by putting a 110 degree glass of water in it for a while and testing it occasionally with the thermometer before you do this the first time.)
5. Check after three hours, but I find the best results are usually between 5 and 7 hours. After a point, all it does is make more whey. However, every so often check yogurt and sop up whey with a paper towel (you can also pour it off and save it for other recipes, if there is a lot--like when I used that really cheap milk!) Depending on how hot your oven is, you can leave it for up to 12 hours. Yogurt is ready when you can tip it and it pulls firmly away from the side of the cup.
6. Transfer to the refrigerator.

You can sweeten an entire batch of yogurt by adding honey and vanilla after you stir the live culture in with the milk, or smaller portions by stirring it into each individual container. I have also put fruit and honey in the bottom of a container before pouring in the culture, but found this made the yogurt very runny, so decided to do it after from now on!

If anyone out there gives this recipe a try, I'd love to hear about your adventures (or misadventures!)

Edit: When I was using raw milk, I found that the recipe was turning out watery and not setting properly, until I realized that too much cream was being skimmed off. I have had the best results with unskimmed milk from a Jersey-type cow. (These cows have a much higher fat content in their milk than Holsteins.)