What You Need
4 cups of milk (whole or 2% for creamier yogurt, but you can use skim milk as well)
2 tablespoons of plain yogurt with live active cultures (can be store-bought or from a previous batch)
1-2 tablespoons of powdered milk (for thicker yogurt), optional
Equipment Needed
heavy-bottomed pot
cooking thermometer
whisk
clean kitchen towel
large glass or ceramic bowl
warm place for incubating the yogurt (can be oven with the light on or Insta Pot)
What To Do
Make sure that all of your utensils, pots, and containers are clean and sanitized to avoid introducing unwanted bacteria into your yogurt, which can create a big mess you really don’t want to deal with.
Pour the milk into then pot and heat over medium heat. Using the cooking thermometer, start to monitor the temperature. Heat the milk until it reaches around 180 degrees Fahrenheit, then remove it from the heat. This will help to kill bacteria that might be in the milk. Allow the milk to cool down to 110 degrees.
In a separate bowl, take about 1/2 cup of the warm milk and mix it with the 2 tablespoons of plain yogurt. Whisk thoroughly until it is fully combined. This is the starter culture.
Pour the starter mixture back into the pot with the warm milk that is left. Whisk very well to make sure that the starter is thoroughly distributed in the milk.
If you want yogurt that is thicker, you can add 1-2 tablespoons of powdered milk and whisk it into the milk mixture. Make sure it is fully combined so that there are no lumps.
Pour the milk mixture into the glass (or ceramic) bowl and then cover it with a clean kitchen towel. Put the bowl in a warm spot and allow it to incubate for 6 to 10 hours. Another option is to place it in the oven, or an Insta Pot or yogurt maker if you have one of these. If you incubate it for longer, then the flavor will be more tangy, so it’s up to you.
Once your yogurt is finished incubating, you can start to test for thickness. At this point, it should have reached a yogurt consistency, but if not, allowing it to incubate for more time until it’s reached your desired consistency. At this point, you can take it out of the warm spot and put it into the refrigerator. Let it cool for at least 2 to 3 hours until the yogurt has fully cooled down and set completely. Once this is done, you can finally enjoy your delicious homemade yogurt!
You can reserve a little bit of your yogurt for the next round of yogurt making. That way, you can continue to make more yogurt without having to buy any starter yogurt from the store.