(I now know by heart)
Heat a gallon of milk up to 180 degrees. (Be sure to keep stirring it, or it will burn to the bottom-If burning occurs: refer to my 75 Ways to use baking soda tip #66.)
Then, place pot in the sink, in a bath of ice water. Let cool to 110/115 degrees.
Then, stir in 16oz of yogurt, and put mixture into a air-tight container. (I suggest using mason jars or other bpa-free containers.)You can also add in vanilla extract or any other flavoring, and/or sweetener at this time,but can what until later (if you'd like).
Incubate for about 10 hours or until yogurt has congealed.
I do this by putting the yogurt containers into a bath of HOT water (inside a cooler). After about 5 hours, you have to pour out the water and fill it back up with HOT water. (I'm not sure what degree the water is, but it's as hot as my tap gets.) After the yogurt has congealed, you can strain excess liquid by stretching cheese cloth across the top of the container and securing it with a rubber band. This makes into something similar to Greek yogurt or Indian curd. Then, it's ready for the "fridge." ("The cold one, not the really cold one"- the way I explain it to my husband, Fabian. [He's from Chile.]) Sometimes, I even throw some into the freezer for us to enjoy with granola and fresh fruit, that evening.