Homemade Yogurt in Mason Jars
Place your filled jars into the cooler and add hot tap water until they're submerged, but not floating. You want the water to be around 120-125 degrees F. I've found that this is exactly how hot my hottest tap water is, so I use that. Makes life easy, too.
Once the jars are in the cooler and it's filled with water, close it and tuck it out of the way for 6-7 hours. You can go as long as 8-9 hours, but keep in mind that the longer it sits, the more pronounced its tang will be. When I was working, I'd often start a batch of yogurt just before I left the house in the morning and let it process all day. It made for a tart yogurt, but I loved the simplicity of it.
When the time is up, remove the jars from the cooler and place them in the fridge. Use your homemade yogurt like you would any other kind of yogurt. If you're interested in transforming your yogurt into a thicker product (along the lines of greek yogurt), all you do is strain it. Well Preserved has a good post on that, as well as suggestions for using up the resulting whey. For those of you who regularly make yogurt, do you have any tips to share?
Find more from Marisa at her blog, Food in Jars. Her new cookbook, called Food in Jars: Preserving in Small Batches Year-Round, is now available everywhere books are sold.