So the basic procedure:
1) Bring 1/2 gallon of milk nearly to a boil
2) Let it cool off
3) Add a "starter" of previously made yogurt
4) Let it sit for about 12 hours until you have yogurt
Honestly, it is that easy: (nearly) boil, cool, starter. People have been making yogurt for nearly 4,000 years. Seriously. During that time, people have made a lot of mistakes. (Well, at least I have in my last 8 months) And yet there has never been the great Yogurt Death of 2400 BC. Or 800 AD. Or 2012. Millions have people have made yogurt, and you can, too! Plus, call me ethnocentric: you are on the computer, you drive a computer and probably have a smart phone. Plus, you easily understand what zero is, which at one point was revolutionary among the greatest mathematical minds. You are smarter than the people from 4000 years ago and YOU CAN MAKE YOGURT.
So here is some additional information until this process turns into "(nearly) boil, cool, starter."
1) We heat our milk in the microwave in a glass bowl covered with a glass plate because the clean up is a boatload easier than doing it on the stove. Cleaning a pot of milk heated on the stove sucks. There is no clean up of heating milk in a glass bowl.
|Milk in glass Bowl|
3) We microwave our yogurt on high between 12 and 13 minutes depending on which glass bowl we are using. You can use an instant read thermometer to check the temp to get over 180.
4) We let the milk cool uncovered for between 50 minutes and a hour to get back down to 110 degrees. This is cool enough to stick your finger in the milk for 10 seconds so it doesn't hurt but it still feels hot. I got that trick from Make the Bread, Buy the Butter.
5) Add between 1/4 and 1/2 cup yogurt with active cultures. This can be from a previous batch or a batch you've bought from the store of plain yogurt. The more starter you add, the quicker the current batch thickens up. I just put in about 1 cup of starter because I want a big batch for tomorrow and there wouldn't be enough leftover for my breakfast yog AND to make the next batch. So I just added it all.
|Starter Yogurt in the other glass bowl we use|
|Wrapping the yogurt in a towel|
8) For me, I think it's ready when there is some liquid on the top of the yogurt (the whey) and the rest of the yogurt looks solid-ish. If the yogurt and whey not separated, we let it sit a little longer. If it's longer than usual, I think it means you're yogurting at a lower temperature or not enough starter, so hang loose and weight a bit more.
|12 hours later....|
|We've poured off the whey|
11) We use non-fat yogurt because I am trying to lose weight, but you can use whatever you'd like.
12) Once, I let it cool too much and there was a skin of milk on the top. I didn't take it off before I started the yogurtizing process and there were some gross, plastic-y bits in the yummy, creamy bits of the yogurt. Now I take the skin off if there's a lot of it.
So that is it. You have all the detailed information that I have gained out of our "(nearly) boil, cool, starter" cycle. If you have any additional questions, leave them in the comments and I will update this post. It still feels like magic every time I make yogurt. If you can boil water, you can make yogurt. And yet we pay TONS more than we need to by buying all this yogurt in the store!! I did a little math last night and using 2 quarts/week of yogurt, saving $5/week (at least), we're saving well over $260/year. Just saying.
I am the yogurt evangelist! Get thee to the microwave and start your own (nearly) boil, cool, starter cycle now.
UPDATE: A friend has found that leaving the oven light on keeps the oven temp at 110 degrees, the perfect yogurtizing temperature!!
Updated Update: We have changed what we do. Microwave 13 minutes. Cool for 60 to 75 minutes. Add 1/4 to 1/2 starter. Put in oven with light on, no towel for at least 16 hours (usually noon until 6 am next day, so I can't really do math). No draining and thick, greek yogurt.