Heat 2 gallons of whole milk in a large pot until it reaches 150°F.

Turn off the heat and let the milk rest at room temperature until it cools to 116°F.

Add 1 cup of yogurt from a previous batch and stir well to combine.

Cover the pot with a lid and wrap it in a large bath towel.

Place the wrapped pot in the oven with the oven light on. Let it rest overnight.

The next morning, remove the pot from the oven and refrigerate for at least 2 hours.

For extra-thick yogurt, scoop the chilled yogurt into cheesecloth bags and allow it to drain for about 2 hours. For thicker yogurt, let it drain longer.

Once drained to your desired consistency, whisk the yogurt until smooth and creamy.

Store the yogurt plain, or stir in a little maple syrup and vanilla bean paste for a flavored version.