With a few inexpensive ingredients and a kitchen oven, you can eat smooth and creamy homemade yogurt. A homemade recipe means you can decide what goes into the yogurt while making it, like fruit, jam or even spices. It's even up to you whether you get a thinner or thicker yogurt. When you make yogurt in an oven, you're saving money and getting more yogurt.
Pour the milk into a large pot on the stove.
Add the powdered milk and stir it with whisk until it is completely blended. The powdered milk will help make the yogurt more firm. If you want a more liquid yogurt, don't add the powdered milk.
Attach the cooking thermometer to the pot and scald the milk at medium heat until it reaches 180 degrees F. Stir the milk often so it doesn't burn. You want the milk to scald but not scorch. Scalding the milk also helps to produce a firmer yogurt.
Fill one side of your kitchen sink with cold water. Place the pot of scalded milk in the water.
Wait for the milk to cool to 110 degrees F. Add the sugar and vanilla and mix well.
Place the yogurt in a bowl. Get the kind that has live active cultures, like Activia or your milk won't turn into yogurt.
Add 1/3 cup of the warm milk to the bowl of yogurt and whisk together until smooth.
Add the yogurt and milk mixture to the pot of milk and stir until mixed.
Preheat the oven to 110 degrees F. Pour the yogurt mixture into the glass baking pan and cover with aluminum foil. When the oven light goes off, put the pan in the oven and shut the door.
Leave in the oven for 4 to 6 hours while the yogurt is made. Don't shake or disturb the pan or the yogurt might not set properly.
Take out of oven when the yogurt has become firm. Set the pan in the fridge for about 6 hours.
If you want a fruit-flavored yogurt, stir some jam into the mixture before putting the pan in the oven.