Saving vegetable scraps in the freezer to make stock is an idea that has never entered my head! I may have to give that a try. That seems like an awfully long processing time for a pressure canner. I'd have to have a good book at hand to read while I babysat the canner; mine has to be constantly monitored because it refuses to maintain a steady pressure.
RE: Making Vegetable Stock for the Pantry -by Sunscape