I saw a reference for making your own yogurt online and remembered I used to do it. Most of the methods you see online make it more complicated than it needs to be. Here is the recipe I had great success with, and you make it in the jars you'll store it in, in a crockpot.
Making Yogurt in a Crockpot
2 qts milk
2 T nonfat dry milk
1/2 c fresh yogurt with active cultures.
1. Run 2 qt jars plus a 1 c jar in dishwasher with lids
2. Fill large crock pot with hot water, set on warm.
3. Measure 2 qts milk large measuring cup, then pour in large pot, and whisk in 2 T reg nonfat dry milk.
4. Heat milk to 185-195 degrees F over medium heat. (on 5 on my stove it takes 18 to 19 min.) Stir occasionally over 150 degrees to prevent scorching.
5. Pour milk back into measuring bowl, set in sink of cold water halfway up handle and cool to 50 degrees C or put in fridge to cool for about 15 min till 50 degrees.
6. Pour ½ c milk into 1 c glass measure, add enough fresh plain yogurt with active cultures to reach
1 c. Stir well.
7. Stir yogurt mix into rest of milk. Ladle into jars and tightly screw on lids. Lower jars into crock pot of water. Let incubate 4 hours. Water should be 50 degrees C. Over 55 will kill good bacteria.
8. Refrigerate when done. This yogurt will not be as thick as that you buy in the store. You can use some of it to make your next batch.