How to Make Your Own Yogurt

Be warned: it really only makes sense to do this if you live somewhere that pasteurized milk is cheap and plain yogurt is expensive. Home-made yogurt is delicious, though, and good for intestinal health.

Equipment required: boiling water, stove with controllable temperature, glass jars with lids, clean water

Time required: 30 minutes prep, 7-24 hours unattended fermentation time

Ingredients:
• 1 - 2 liters milk
• About half a cup of yogurt as a starter – commercial yogurt works well, or homemade yogurt that is less than a week old

Instructions:
1. Sterilize your jars. Set them upright in a baking pan or large pot with the lids upside down next to them, and fill them with enough boiling water to fill them up and run down the sides. Do the same with the lids. Leave them there full of water and go to the next step.

2. Heat your milk. Put it in a pot, and heat in over medium heat. Watch it very, very carefully. You want to heat the milk until tiny bubbles form where the milk touches the edge of the pot. Then remove it from the heat. The amount of time will differ depending on pot size and what kind of medium your heat is, so watch it like a hawk. Time it for the next time you make yogurt.

3. Let the milk cool. You want it to cool to about 110 Fahrenheit. If you don’t have a thermometer (I don’t) that is the temperature of a nice hot bath. You can feel the outside of the pot to test the temperature, or do what I do and test it with a clean finger.

4. Add your starter. Once the milk is the right temperature, add one tablespoon of yogurt for each liter of milk. Stir it thoroughly to distribute the starter through the milk.

5. Pour the water out of your jars. Pour in the milk. Put on the lids.

6. Now you need to let your milk turn into yogurt. You want it to sit at 100 degrees to encourage bacterial production. That’s almost exactly body temperature. A sunny windowsill works, or an oven with the light on. I put mine on the warm spot on top of the fridge, and cover it in a dishtowel to hold in heat.

7. Let it sit undisturbed for at least seven hours. Moving it around is bad for the bacteria. After seven hours, it will be yogurt. A little runny, but recognizably yogurt. The longer you let it sit, the thicker it will be. I leave mine for about twenty hours to get the thick greek-style yogurt. There will be yellowish liquid on top of your new yogurt. That’s whey; just pour it off if you don’t like it. There is not too much of it - you can see they whey in the picture up there; it's that thin line on top.