Houston is hot, no denying that, and I love to take advantage of the temperature whenever possible. We use solar energy to dry our laundry (it’s called a clothesline). Alton Brown once told me how he tried using his mailbox to bake biscuits.
We used to have an older car that was always parked in our driveway. I found that it had the perfect environment for sun-drying tomatoes on the dashboard with a cake cooling rack and a towel underneath. (I didn’t have to worry about bugs as I would have if I had dried them outside.) The car also turned out to be an excellent environment for making yogurt.
Begin by bringing ½ gallon of the milk of your choice to at least 180 degrees F in your microwave.
Let the milk cool to 105 degrees F. If a skim forms on top, just remove it. When it reaches 105 F, whisk in 1 tablespoon of yogurt with active cultures. I have had success using Dannon plain, Activia and Nancy’s. Flavor-wise, I tend to like Dannon as my starter.
Don’t be tempted to use more than one tablespoon You are looking for a slow ferment over a 24-hour period. Cover the Pyrex with aluminum foil or plastic wrap, or transfer to another container (stainless steel or non-stick since the yogurt is going to be acidic) with a lid, and leave in your car for 24 hours. You may discover that when you check it at 16 hours or so, it will still be liquid-y. But trust me, if your starter culture was active, it will eventually solidify.
I usually strain mine to make a yogurt cheese for cooking and for lassi. – Jay Francis