Homemade Yogurt in the Cooler

My current grocery shopping goal is to plan two weeks ahead and shop once.  I did a big shop over the weekend but got home and realized I forgot the yogurt for our smoothies.  Then I remembered that I used to make the yogurt all the time!  It's so easy - it takes 10-11 hours but just a few minutes of hands-on time here and there.  So, I made a half gallon for about half the cost of buying it in the store (I've been buying milk from a local dairy - if I'd used milk from the grocery store it would have been even cheaper).

To make half a gallon of yogurt:

You need a half gallon of milk and 2 T. of plain yogurt. Your starter yogurt should just be made with milk (or milk and cream) and live cultures - don't use anything sweetened, flavored, or with gelatin.  It won't work right.  

1.  Put milk in a lidded bowl (I use the Pampered Chef Batter Bowl). 

2.  With the lid off, heat in the microwave to 180 degrees (Fahrenheit). This takes about 12 minutes in my microwave, but I do in three minute bursts so I can stir it regularly and check.  You can also do this on the stovetop in a large pot but I don't want to babysit it that much.

3.  Let cool to between 110 and 115 degrees.  Stir regularly (every 10 minutes or so) to prevent a skin from forming at the top of the yogurt (no need to remove it, just stir it back in).  This takes about an hour. While it cools, get your starter yogurt out of the fridge to come to room temperature.

4.  Stir a few tablespoons of the warm milk into your starter yogurt to thin it out, then stir that into the bowl of milk, mixing thoroughly.

5.  Put the lid on the bowl and put it in a cooler.  Pour enough hot water in to go 1/2 - 2/3 of the way up the side of the bowl.  Your hottest tap water should be fine for this. 

6.  Put the lid on the cooler and cover it with blankets (I put it on a twin size blanket so that it can wrap all the way around, then put another small blanket on top).  Let stand for 8 - 10 hours, until thick. Keep refrigerated.