Asked May 4, 2013, 2:39 PM EDT

I have three questions. I saw your YouTube presentation, which was wonderful, and I have since canned blueberry jam twice in my pasta pot. What happens is that when I begin to process, there is about an inch or so of water over the jars, but as the process goes on and the water boils, I lose the water as it becomes steam. By the end of the process, the jars are no longer submerged. In fact, they are sticking up above the waterline. Nevertheless, I hear the lids pop, and when pressed, they appear sealed. Is that a good seal? Can I put them in the pantry without refrigeration until I open them?

My second question goes to filling the jars. Sometimes, at the end, I don't have enough to fill the jar to a half inch from the rim. I process as described above and hear the lid pop, and when I test the jar, it feels sealed. Is that okay?

Final question: I am from Florida and at sea level, so I can boil the cans safely. However, I spend time in Colorado. At high altitude, what do I need to do differently if using the boiling-canner process?

Miami-Dade County Florida food safety home food preservation canned foods canning food preservation

1 Response

I am glad the YouTube presentation was helpful. We like to hear that. The National Food Preservation website is, and the site contains a wealth of research-based information.

Question #1: You can have 1 to 2 inches over the jars, so I recommend that you have 2 inches over the tops of the jars to start off. But you can add boiling water during the canning process—not on the jars, but along the edge so the water doesn't go directly on the jars. Have boiling water ready and add it when the water starts to get low.

Regarding the canning you have already done, even though the water was below the lids, which isn't recommended, the jars are fine since the lids are sealed and you heard them pop. You can store them in the pantry.

Question #2: It isn't a good practice to can jars that are not full. Go ahead and use the ones you have canned that aren't full, but in the future, put the jar that isn't full in the refrigerator, before you process it, and then use it within a few days.

Question # 3: At high altitudes, add 5 minutes to the processing time when water-bath canning.

Since it sounds as if you are really getting into canning (good for you!), Michigan State University Extension recommends So Easy to Preserve and the USDA Complete Guide to Home Canning or Preserving. You can Google either of these and purchase them online. Ball Blue Book is also a reliable recommended resource.