Yesterday was yogurt making day, something I do about three times a month. Usually I use the "heating pad method" where you heat up your half gallon of milk in a double boiler to 185 degrees, then cool it to 110 and then add and stir in your yogurt starter (usually just about a quarter cup of yogurt from the last batch I had made). After that you cover it with a clean dish towel and let it sit on a heating pad set to medium for 7 hours. However this is what I saw on the thermometer in the shady comfort of our back porch:
Yes, that reads 115. I decided to try using the cement on the back porch as my heating pad from 2pm to 9pm. I was a little worried that the temperature might get too hot or not hot enough, but at 9, it was time to take the towel off, and it worked perfectly. Solar Yogurt? It's a go! I was very pleased and will be doing it this way until about October. Next, I'd like to heat up the milk in the solar oven, which will be a little bit trickier...
