Making your own yogurt is deeply satisfying. Like baking your own bread or making your own cheese (or even just making your own dinner from scratch!) it gives you a sense of empowerment over your own food choices. It is easy to start it up and you just need to be around to keep an eye on it, while it ferments. You need to keep it at a steady temperature. This recipe is for people who do not already have yogurt makers and are wondering if they can just do this at home with equipment they probably already have.
It would be good to make this on a stay-at-home day. Some people ferment their yogurt during the night, perhaps using a yogurt maker or crockpot. But I start mine in the morning and keep an eye on it periodically throughout the day. The idea is to let it ferment at about 100 degrees for several hours. Do the way that works best for you.
Warm the quart of milk gently in 2 quart (or so) pot until it reaches 180-190 degrees. Take off any skin that formed over the top. Set it aside now to cool to 100 degrees. The idea of heating was to kill any bad bacteria or enzymes that might prohibit the good bacteria growth.
While it is cooling, start heating up your large pot with enough water to not quite cover your jars. I usually fill it up half way. Why the large pot? Because the large the amount of water it sits in, the longer it will take to cool off and the less frequently you have to check on it. YOU ONLY NEED TO HEAT IT TO 100 DEGREES! This does not take as long as you might think.
So, your large pot is heating up and you milk is cooled down. Now add your yogurt 'starter' and whisk it into the milk. If you are using gelatin, add it to a small amount of cold water. Let sit for a minute then mix it into the milk and whisk. I like our yogurt to be on the thick side so I do add a little. I have done it without and it is fine, just more runny. Whatever your personal preference.
Pour the milk mixture into your clean canning/mason jars. Leave a little room at the top for expansion. Put lids on tight and set them into their water baths. Make sure the water does not go over the lids. Your work here is done! Now it is just a matter of maintenance. You must check the water ever hour or two (depending on the warmth in your home, you will get a feel for it.) and try your best to keep it around 100 degrees. I usually put the burner on under it every 2 hours, setting my timer for 3 minutes. If it gets over 110, you are in danger of killing the good bacteria that is fermenting your milk into yogurt. Once it gets to 92-95, then I know its time to reheat.
Leave it for anywhere from 6-12 hours! The longer it sits, the sharper the taste and the thicker it becomes. I usually end up in the middle, from 7-9 hours before taking it out, letting it come close to room temperature, then putting them in the fridge. I have a batch brewing right now while I write this. And some garlic potato rosemary bread rising. And will take the dog to the groomer soon. You see, it does not really tie you down as long as you can check on it every couple of hours. I could use the oven , but it does not go below 170 and I am a little nervous about keeping it in there. (out of site-out of mind). Anyway, mix in some fresh fruit and enjoy a healthy snack or breakfast!