The above (plus an oven, a saucepan, a towel, and a few extra bowls) is all that this recipe requires.
Preheat oven to about 100 degrees C (200 F)
Heat 1 liter (1 quart) of milk (non-fat or full-fat, depending on your preference) in a saucepan until it reaches the boil. Keep a close eye on your milk -- it's liable to boil over quickly (as mine did.) Once it boils, reduce the heat and allow to simmer for about 2 minutes.
Remove from heat and let stand until the temperature cools to 43-46 degrees C (110-115 F) -- if you don't have a thermometer, just wait until the milk feels warm, but touchable. If a skin has formed, try to skim off most of it.
Stir about 1/4 cup of natural yogurt into a bowl with about 1/2 cup of the heated milk, then transfer back into the saucepan and blend.
Turn off oven.
Divide milk/yogurt mixture into two bowls, cover with plastic wrap (or I used re-usable, shower-cap type covers) and then a towel. Put into oven and allow to sit overnight (6-15 hours - - I erred on the lengthier side.)
I was a bit surprised at how well this worked. I even fudged all of the particulars (amounts, temperatures, times....) and it still set. Amazing! I mean, of course -- yogurt has been around for about 4,500 years. Long before grocery stores, yogurt makers, or mixes.
This yogurt was a bit runnier and milder than store-bought, but apparently, the longer it stays in the fridge, the tangier it gets. S ate his for morning snack with cinnamon, I put some in the black bean soup I made for lunch, and baby A had hers straight -- the milder taste suited her just fine.
At a fraction of the cost of ready-made yogurt, we're definitely signing up to be card-carrying members of the culture club. (Yes, Groan. Sorry, couldn't help myself. Yogurt jokes abound!)
