I started making my own yogurt when I once (okay, maybe twice) bought those Danimals yogurt smoothies for my kids. They just loved them, but Danimals is pasturized which kills all of the friendly bacteria in the yogurt. I just thought, how is this different than my making a smoothie for them at home? The only difference was at home my smoothies wouldn't have tons of sugars, preservatives and thickeners in them. Ouch. When you make your own yogurt, you can be assured that your yogurt is just what it is supposed to be, milk and culture.
Making your own yogurt at home is super easy and lots cheaper than buying it at the store (not to mention free from all of the thickeners, preservatives and hidden sugars in the super market variety). Even my boys love plain yogurt (albeit with a tablespoon of jam or honey stirred in). It is much easier with a machine which costs around $20 and paid for itself in my house in about six weeks, but if you are not inclined, I'll go through the procedure for making yogurt without a machine too.
Making yogurt with a machine
1. Place 42 oz. (the amount of milk will depend on the capacity of your yogurt machine, mine holds 6 glass jars which hold 7 oz. each) 2% milk in a saucepan with high sides. If you like thicker yogurt, add 1/4 - 1/2 cup nonfat milk powder to the milk and stir in.
2. Turn your burner on high to scald the milk. The idea here is to get the milk to 180 degrees to kill all of the bad bacteria (because that too would grow along with the good bacteria if we did not do this). Do not walk too far away from the stove. When the milk starts to crawl up the sides of the pan (wait for it...wait for it...) QUICKLY take the milk off of the heat. If you miss the moment it starts to crawl up the pan, you are going to have a huge mess all over your stove.
3. Let the milk cool to at least 120 degrees F. Yogurt cultures grow best between 100 degrees and 120 degrees F. If you add the cultures to milk that is too hot, you will kill your cultures and end up with warm milk at the end of your incubation time instead of yogurt. I have timed the cool down process and if I always use the same pot, the cool down time is 30 minutes. What makes yogurt making so easy is that once I did the initial timing of how long it takes to cool, now I can just set a timer and do other things during this time.
4. Once the milk has cooled, take a small amount of milk out and stir your starter into this. Then pour this into the rest of the milk and stir in. You can either buy commercially available starter, found at health food stores, or just use a half a cup of your last batch of homemade yogurt. I always use the commercially available starter because I think it yields a more consistent and slightly thicker yogurt.
5. Pour the cultured milk into the yogurt machine jars and turn the machine on. The machine acts as an incubator keeping the yogurt at a consistent temperature of between 100 degrees and 120 degrees F.
6. After 4-8 hours, remove your jars from the machine and put in the refrigerator for at least 2 hours. The amount of time you leave the jars in the machine will depend on how firm and tart you like your yogurt. After 4 hours, you will have a softer and very mild yogurt, after 8, more tangy and firm.
I do this twice a week. When I think that is 12 jars of yogurt my family goes through and I can buy a container of yogurt at the store for $0.50 (when it's on sale), that would be $6.00 a week in yogurt. I can buy a gallon of milk for $3.00 which is a savings of $3.00 a week. In just 6 weeks, my yogurt machine paid for itself.
Making yogurt without a machine
For the perennial cheapskates out there (I can relate) who don't want to splurge on their own yogurt machine the process is basically the same, except that you are going to have to find your own way of keeping the yogurt between 100 degrees and 120 degrees F for 4-8 hours. I've heard of one woman who puts her cultured milk in a thermos to keep the temperature consistent. Also, if you have an oven with a pilot light that keeps the oven around 100 degrees, you can stick it in there. I don't have either of these so when I was making yogurt without a machine, I would put my jars in a pot of 117 degree water, put a lid on it, and then wrap the pot with three towels that had been warmed in the dryer. Without the machine, I viewed yogurt making as a little more of a chore and definitely more complicated than with the machine, but if you insist on doing it this way, people have been making yogurt this way for thousands of years, so it is possible (just more fussy).
Pleasure in plain? Oh la la. Enjoy!