Heat the milk in a saucepan to 180°F. Cover the pan and cool to about 116°F. Remove about 2 cups of the warm milk to a small bowl and whisk in the yogurt until evenly combined. Whisk that back into the pan of milk. Pour into jars or a bowl. Cover tightly with plastic wrap or a lid and place in a warm dry place at least six to eight hours or until thickened, overnight if necessary. A good place for this is an oven that is off but has the interior light on.

When the yogurt is set up, place in the refrigerator for four hours. After four hours, line a colander with fine mesh cheesecloth or a clean tea towel. Pour the yogurt into the colander. You can either gather the corners of the towel and tie it before hanging it over your sink for 5 hours or you can place the colander over a bowl and place in the refrigerator overnight to drain.

After draining to desired consistency, turn into a bowl with a tight fitting lid and refrigerate until ready to use.