Before diving into the fascinating fundamentals of yogurt-making, you may like to know why anyone would want to make their own yogurt when it is so readily available at the local health foods store/grocery store/walmart. Four reasons:
1) It’s much cheaper, especially if you buy your milk in bulk.
2) You can decide what kind of milk goes into your yogurt. Maybe you prefer hormone-free milk or maybe you are lucky enough to have a source of unpasteurized milk.
3) It’s more fresh.
4) Satisfaction. Or fun. Or maybe scientific interest.
Home-made yogurt recipe
- 2-3 liters cow’s milk* (any milk will do, as long as its not ‘ultra-pasteurized’)
- 5-6 tablespoons plain yogurt
*we are still perfecting our goat yogurt recipe. I suspect it works better with raw goat’s milk.
In a large pot, heat the milk on low, stirring occasionally until it reduces about 10%. Be careful not to burn the milk on the bottom. This takes 1-4 hours depending on what heat you use. Lower heat preserves more nutrients, higher heat is faster. If you are really anxious, you can turn the heat up and stir constantly until the milk bubbles up and then turn the heat to low and allow it to reduce.
Remove the pot from the heat and allow to cool just until lukewarm (it should no longer be steaming). Add the plain yogurt (this is your cheat), stirring well until mixed. Cover the mixture.
Place somewhere draft-free with a constant temperature like your oven (turned off, of course) a closet, or just wrapped in a blanket in the corner. In about 18 hours, you will have yogurt. Leave it longer than that and you will have sour yogurt, great for doogh.
We refrigerate the yogurt a couple hours before eating, but this is just because we are used to cold dairy products. In the past, dairy was consumed at room temperature because it was always fresh.