In a large pot, heat fat free milk to 185°, stirring constantly.

Keep this temperature for 30 minutes, stirring occasionally.

Meanwhile, fill sink with cold water and ice.

Remove pot from heat and place in ice bath until milk reaches 110°.

Remove pot from ice bath and stir in yogurt.

Wrap pot in a towel and place in turned OFF oven.

Turn oven on and off, BRIEFLY, to check temperature. Temperature should not drop below 110°.

Leave overnight or up to 12 hours, undisturbed.

Refrigerate for another 8-12 hours, undisturbed.

Note: as hard as it will be not to look, you must not peek. Let the yogurt cultures do their job! You will be glad you did.

After the refrigeration period, set 1 cup aside and freeze to use for your next batch.

Sweeten and/or flavor to your liking or enjoy plain and tangy!