I'm new to canning so you could write a book about what I don't know about canning so please bear with me. I noticed in another thread Super Dave (I think that was the name) said he bought two presto canning racks to use in water bath canning and placed one on the bottom then stacked his jars then placed the other rack on top of the jars and then made another layer of jars - did I read this correctly and if so do you have to make any adjustments in cooking time, etc. for that many jars? If I did understand it correctly that sure would be a time saver. I guess you would also have to make sure you have enough water covering the tops of the jars on the top layer.