Yes, you can! I did it!
I made my first successful batch of yogurt this week, and it's super easy! Here's the recipe:
Homemade Yogurt
You need:
1 quart milk
3 T. plain yogurt (just purchase 1 small individual serving-size container) or 2-3 packets yogurt starter
1 candy thermometer
1 stirring utensil
1 quart-size Mason Jar (with a lid) or Yogotherm
1 picnic cooler with a tight fitting lid (if you don't use the Yogotherm or have a gas oven)--large enough to hold all your Mason jars and a cooking pot or tea kettle
1. Heat the milk to 180-185 degrees (using candy thermometer to be exact).
2. Allow milk to cool down to 110-115 degrees (again using candy thermometer).
3. Stir into the milk either your yogurt starter or the container of plain yogurt.
4. Pour milk into your quart Mason jar (or Yogotherm container).
5. Put on the lid of your Mason jar.
6. Place your Mason jar in the cooler with a pot or tea kettle of hot water. (I put a towel around it inside the picnic cooler.) Another option is to fill a small cooler with near boiling water coming nearly to the top of your Mason jar. Another option, if you have a gas oven, is to put your Mason jar into the gas oven, as the pilot light keeps the oven at a warmer temp. Don't turn on the oven! If you live in a tropical zone, you can just put a towel over your jar and set it on your kitchen counter.
7. Put the lid on your cooler and let set for 4-16 hours. Don't peek or move it!
8. Done. $10-12 worth of yogurt for $2-3! One woman estimates she saves $200/year just on this one make-at-home project.
9. To serve, you can add the fresh or frozen fruit of your choice. If you put it all in a blender with some extra milk, it makes a great smoothie!
Thanks to Joy for the idea and recipe.