Ah yes the workhorse of the underground canning world. I have seen more paw paw jelly and pickle ramps in this jar than you can shake your slow food membership card at. My friend Chris Curtain (grand cru chocolatier) told me a story of Germans baking in these jars. I did it, brilliance. I baked with the lid off, and then put the lid on the hot cake, it is supposed to last for months this way. Some people bake lid on.