I do know that you are not suppose to can Jet star tomatoes. They are a low acid tomato. My question is what do you add to them be for you can them. I have used lemon juice. The only reason this has became an issue is because in Oklahoma it has been so hot I only got to can 5 mason jars of tomatoes. That is very low for me. The only plants that seemed to make it thought the heat was the Jet star tomatoes. I Use pint mason jars.