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Jun 19, 2010 12:16 PM

Canning jars leaked a little in processing--okay or not?

I canned some whole blueberries in syrup this afternoon. This is only my second time canning and I think I may have overfilled the jars a little. As I took them out, I noticed some syrup leaking out around the rims and they ended up sitting in small pools of syrup as they cooled. The water in the canner was only very slightly blue and they only seem to have leaked a little. They all sealed correctly. Are they okay? If not, what do I do?

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  1. I would re-can them. A proper seal is is of utmost importance. If they've leaked at all (this is called 'siphoning' in canning speak) the seal has been compromised; food particles in the syrup got under the lid and may have interfered with the seal, and the jars are not sealed properly.

    When you wrote "They are all sealed correctly," do you mean no popping or flexing of the lids? It's possible they may have sealed, but if you choose not to recan, mark them to be eaten first, and soon. The fact that the jars continued to leak ("sitting in small pools of syrup") while cooling tells me that the seals are not ok.

    Do they leak at all when turned upside down? Is the lid concave when looking at it from eye level? A concave lid indicates a good vacuum seal.

    To re-can, just go through the process again, sterilizing the jars, heating the fruit, filling to the proper level and processing in the water bath. Did you raw pack or hot pack the fruit?
    If they were raw packed you can reheat the fruit in the syrup just to boiling without the berries breaking down too much. How many jars did you can? In lieu of re-canning and having the berries break down more, you may want to just keep the jars in the frig.

    You can always get some pectin and make blueberry jam with them.

    5 Replies
    1. re: bushwickgirl

      "In lieu of re-canning and having the berries break down more, you may want to just keep the jars in the frig"
      Along with everything else you thought exactly! .

      1. re: Uncle Bob

        Yes, the lids all sealed and are concave in the middle. They do not leak when turned upside down. Does this mean they are okay?

        There are 6 pints. I could probably find room in the fridge, but if I do that, how long will they keep? We will probably eat them within 4-5 months no matter where we store them.

        They were raw packed. I must have overfilled. I don't quite get this since I even measured a 1/4" inch headspace. BUt they are chock full to the very top of berries and syrup now. ??

        My understanding was that fruit is not a botulism risk due to acidity (these were canned with Fruit Fresh). True? What do I risk here--losing product, or something worse?

        Thank you!! I also made some refrigerator pickles--boy, those are good.

        1. re: loraxc

          If they are refrigerated, I should think that using them within 4 months or so would be fine. I just finished some blackberry syrup (just cooked, not canned) that was open and two months old and I didn't notice any deterioration.

      2. re: bushwickgirl

        They are okay if the seal is good. It's completely normal for them to vent juice when sealing. Here's the official answer from the USDA on that:

        So, no worries about that.

        In the Ball Complete Book of Home Preserving, it recommends leaving the hars in the water bath hot water for 5 minutes after processing, and it will prevent it.

        1. re: momskitchen

          I agree, venting while canning does not mean it needs to be reprocessed as long as you have a secure seal once they are cooled.

      3. I don't think that is true about fruits [think pears, apples, etc] not being a risk for botulism. In fact, there was a case of botulism from home canned blueberries - my memory is fuzzy on when/where but I do remember it was blueberries. Even with tomatoes there have been rare cases of botulism. I would either keep them refrigerated or recan them. [Is recan a word???? My spell checker is unhappy with recan : ) ]

        4 Replies
        1. re: Bethcooks

          I just looked this up because I wasn't sure either.

          "However, there's an extremely easy way to play it safe: lemon juice. Botulism cannot survive in an acid environment, and so canning acidic fruits like apples, peaches, or berries means no botulism risk. "


          "Bacteria is what causes Botulism. Botulism is a very serious type of food poisoning. It thrives in low acid and oxygen free environments. This bacteria will only be killed in very high temperatures of over 240 degrees F. These temperatures are achievable under pressure, but NOT in a water bath canner. Repeat: Canning food in a pressure canner stops botulism, a boiling water bath does not. "

          So if we were worried about botulism in fruit, we wouldn't water-bath can.

          "properly acidified foods like pickles and high-acid foods like fruits aren’t botulism risks."

          I think tomatoes are a special case because some varieties are low-acid.

          1. re: loraxc

            Blueberries are high acid, which is why you can BWB can them.

          2. re: Bethcooks

            Actually there has never been a case of botulism because of home canned fruits....only vegetables and meats:


            I am very particular about food safety when it comes to canning, so I can appreciate your worry. However, the pH of fruit (except tomatoes) is less than 4.6. Botlulism can't survive a pH of <4.6. The pH of of blueberries is around 3.1 - 3.2,. so it's good. Here's a list of the pH of foods from the FDA, if you are worried, you can check it out whatever it is you are making just to be sure:


            Hope this helps! Check out my blog if you'd like to read about it

            Tomatoes have wildly fluctuating pHs, that is why you ALWAYS have to add acid to them (veinagar, lemon juice, etc)

            1. re: momskitchen

              Thanks for the links. I assume relishes with vinegar are also pretty safe. I am trying my hand at zucchini relish today.

          3. A second thought: we have access to a state home extension phone line that would give a definitive answer to your question. Perhaps you do also?? I also think Ball Jar has a hotline/email where you can ask questions.

            12 Replies
            1. re: Bethcooks

              I bet they would tell me to reprocess. Can you tell I don't want to? ;) I have little kids and it's hard to find a time to concentrate on a canning project.

              1. re: loraxc

                The only rule of thumb you need:

                If not doing Action X will make you worry every time you take a bite, then YOU MUST DO ACTION X.

                Re-process them. They're most likely just fine, but you'll fret that you're poisoning your family every time you watch someone take a bite if you don't.

                To be honest, they're probably not OK to leave on the shelf.

                1. re: dmd_kc

                  Honestly. I am not that inclined to worry. Maybe that makes me too complacent! But since it seems botulism is basically not a risk for canned fruit, I am not that concerned. Regular old mold and spoilage can and do happen in other situations and I don't worry about killing everyone, you know?

                  1. re: loraxc

                    Ok, it seems like we just can't twist your arm enough to convince you to re-process the berries. So just keep an eye on them for any signs of bulging lids, unnatural odors or mold growth. Mold is an indication that the ph has changed in the fruit and it should be disgarded. Since you can't be totally positive that your seals are good, please consider refrigerating your fruit.

                    1. re: bushwickgirl

                      Actually, I may reprocess. I'm just stubborn. ;) I also don't want to turn my blueberries to tasteless mush. But really I'm also trying to understand the actual risks involved. There seems to be a ton of confusion about botulism and canning, and I think it would be helpful to me to understand this further. The thing I did read that may convince me is what you just mentioned--if mold develops, it can change the pH of even acid food and make it hospitable to botulism. Of course, if I saw mold I wouldn't eat it anyway, but maybe there could be mold I wouldn't notice.

                      1. re: loraxc

                        "blueberries to tasteless mush" It's a possibility, unfortunately, but you did raw pack, so they have a fighting chance. Even though they may get mushy, they will still have flavor. You may end up with chunky blueberry "sauce." That's why I suggested making blueberry jam, but there's more work with that, as well, and changing up precooked fruit with sugar and adding the proper amount of sugar the pectin needs to work properly may create issues of it's own.

                        Just heat the fruit to boiling, sterilize the jars, new lids, proper headspace, process and hope for the best texture with the berries. If anything, they'll make a good sauce for ice cream.

                        I wish you the best, and keep canning, everyone messes up in one way or another in the beginning. I had leaks as well, and jars that didn't seal. I also could never get my blueberries not to "float," with an inch or so of liquid at the bottom of the jar. After years of this happening, I just decided it was normal. They settle down and sink after a few days.

                        1. re: bushwickgirl

                          I reprocessed them. Oy, what a pain in the neck. They all seemed really sealed tight, too! On the plus side, I got to hear the lids go "dink" again (this is my favorite part).

                          I left more headspace this time and had no leakage. I guess maybe it's better to err on the side of too much space (I did this the first time and now some of my strawberry jam is a little discolored).

                          1. re: loraxc

                            Yes, pain in the neck, but the right thing to do.

                            That discoloration is from too much headspace, but just scrap it off.

                            Good, I'm glad you reprocessed them, now I can sleep tonight.;-))

                2. re: loraxc

                  Of course they would, they would want to CYA. It's like calling the emergency room and telling them you have chest pains. It could be indigestion but they are going to tell you come in to the hospital just to be safe.

                  Not sure why I'm bothering answering this 2 year old thread where the food is likely eaten or thrown away by now. I really need to remember to check the dates since Chowhound thinks every topic should live forever.

                  1. re: rasputina

                    Oddly enough I happen to be here today (I'm the OP). I'm a far more experienced canner now. I don't think I needed to reprocess these. Ths seal was good. Still, bothersome and unnerving. Blueberries have given me trouble more than once (JUST blueberries, actually).

                    1. re: loraxc

                      I just canned blueberries this summer and same things happened to me, much more than everything else I've canned before, as well as strawberries. Just curious how you used your canned berries?

                      1. re: geminigirl

                        I wish I remembered! I do know that I wasn't that pleased with them. We all prefer blueberry jam (though it makes your teeth horribly blue). Plum-blueberry jam wa s a huge hit this year--I had really good plums, though.

              2. Yes you overfilled the jars. (Easy to do, he said knowingly.) No less than 1/2 inch of head space is needed. (Yes that extra 1/4 in. makes a difference.) Even 5/8 in. would probably be o.k. for the jars to seal.

                I, too, would re-process them. Use new lids and make sure the top rim of the jars are clean. Even tho they sealed, there is a chance mold to grow on the juice between the seal and jar. IMO, it's not worth the risk.

                Otherwise, the frige storage suggestion is a good one.

                1 Reply
                1. re: al b. darned

                  loraxc, in the future, go here for instructions.


                  I'd store those berries in the fridge. And mold doesn't change the pH, it grows if the seal fails. Fruit is normally acidic, so it prevents the growth of bacteria, but it's always hospitable to mold. When you process fruit, you put it in the hot jars, then wipe the rims of the jars to insure a tight seal. If you overfilled the jars, the contents expanded enough to overflow the lid and in doing that they probably compromised the seals. If you don't want to reprocess the contents, consider freezing them in plastic containers instead.

                2. this happened to me too, with jars of canned tomatoes in water. there is just a bit of sticky residue around the rims, but the seal seems 100% intact and i did leave 1/2" head space. could they have leaked just before the vacuum seals formed while they were first taken out of the canning bath?

                  2 Replies
                  1. re: helenhelen

                    If you are an experienced canner and the seal seems 100% intact, I would use these and not recan. Research "siphoning/canning."