I hate it when I have bubbles in my canning jars when I'm finished! I used to get freaked out that they were no good. My mom taught me a thing or two about them. It's almost impossible to get all the bubbles out. I stick my knife in the jar and move it up and down. I don't overfill/under fill the jars. Sometimes the bubbles just appear! The only time you have to worry about bubbles is if the bubbles get fizzy or start to move when you open the jar. If they do this then you should toss out the contents. Anyone have anything else to add about bubbles?