Can I use my 6 qt pressure cooker to can deer meat properly? Do I need a wire rack to keep the jars from bumping each other or can I use a rack to keep the Mason jars off the bottom? My cooker doesnt have a dial gauge or a weighted gauge so can I just get the pressure up until it starts to whistle and cook for 90 min? I'm trying to nail down this procedure without buying another pressure cooker. Anyone help, thanks. -Mike