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eeeek: urgent homemade jam food safety Q

Help! My husband and I made blackberry jam a few months ago. We brought some jars out of storage in preparation to bring them to family and friends over thanksgiving. However, my husband noticed that some of the jars are oozing jam. The lids' dimple is still depressed. Are these safe to consume?

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  1. If you took all due precautions in sterilizing the jars and caps and boiled appropriately afterward, it sounds as if they were filled too high. If the dimple is still depressed, you're not getting any gas in there from decomposing bacteria. That's good. However, the best way is to open one up and sniff and taste for anything amiss.

    NB: This is an educated guess from the son of a jam, jelly and preserve expert. My dearly departed dad could have written you tomes on your question.


    1 Reply
    1. re: Chefpaulo

      I agree that they were probably overfilled but I would make very sure when you open them to check that you did indeed have a seal. Listen for that slight hiss when you break the seal on the lid. If the lid lifts right off with no effort the odds are you have no seal. A sniff and taste test is not sufficient to determine whether or not the jam is still good. Some very nasty critters can't be detected that way. If in doubt, toss it.

    2. Sugar and acid are both pretty wicked preservatives. I would eat 'em -- shoot, the human race somehow survived the days when paraffin and oiled paper were the "lid" on preserves. ;)

      1. I'd feed some to the dog first.

        No, I'd feed some to someone else's dog first.

        No, really, I'd toss any jars that are oozing. Even if you overfilled them, there's no good reason why the jam should expand after it's been removed from the cooker, and regardless of how the dimple feels now, I don't see how jam could ooze out if the seal were truly intact.

        I'm the first to agree that many people worry way too much about some food safety issues (full disclosure: I don't always cook pork to 160F, make salad dressings with raw eggs, and love tuna tartare). Lauragrace is right in general, although I suspect there were just a few members of the human race who did not survive that last jar of jam sealed with parafin or oiled paper. But Morwen is also right. If food poisoning had a distinctive taste, nobody would get food poisoning.

        1. I would eat it. You did not leave enugh "head space" when you filled the jars and they oozed when you boiled them. Since they are sealed, the ooze apparently did not interefer with the rubber gasket and they are probably fine. The big spoilage factor for jam is mold - which is usually quite visible. The high acid and sugar content make them pretty safe - as one poster pointed out, my granmother taught methe parafin eal and I did it fro years with no adverse conequences.

          1. I'll have to chime in with LauraGrace and Junoesq. Sugar and acid is not a bacteria-friendly environment. If you were canning any animal product (pickled eggs, pickled pigs feet *yuck*) and your jars were seeping, in the hopper they'd go. But high sugar content is a safeguard in itself.

            My family owned the American Preserve Co. in Philadelphia from 1912 to 1956. Dad was Vice President and chief chemist from 1939 until the company was sold. When I was about seven,I remember showing him a half empty jar of raspberry preserves that had been in the fridge for quite a while. It had some white mold on top and I asked if I should throw it out. Dad assured me that the mold was surfactant (my new word of the day) and that it just needed to be scraped off the top and all underneath was fine. He then did so and put the unaffected jam on toast. No ill effects and he lived another 43 years.

            I really think you just overfilled them and that nothing insideous is in there.


            2 Replies
            1. re: Chefpaulo

              In a home canning situation overfilled jars are apparent as soon as you pull them out of the waterbath. They will either be already oozing or if the preserve has washed into the water the sides will be sticky when the water dries. My concern is if they didn't notice this upon pulling the jars out or putting them away, something may have been wrong in the recipe. For example, if using a regular pectin or no pectin, not enough sugar to reach a preservative level or jam/jell set, or undercooking. In any case what could have happened was the creation of an anaerobic environment for ferment (sugar is the food Acetobacter bacteria eat) which would explain the later seepage, pressure formed by the ferment forcing the jam through the seal. What they have could be innocuous or maybe not. I stand by not taking a chance. If what wasn't seeping upon being stored now is seeping I'd throw it out. Like Clint says, "ya gotta ask yourself, do ya feel lucky?"

              1. re: morwen

                Oddly, it was the recycled bon maman jars that have had the problems, particularly after flying. We used preserving sugar with extra pectin for soft fruit (and actually over cooked it).

            2. If there is any question, it is one thing to eat it yourself, it is entirely another thing to give as gifts.

              1 Reply
              1. If you made it properly, jam does not go off. The question is, how reliable was your recipe and how closely did you follow it? (btw, if in any doubt about it, I wouldn't give it as a gift...)

                7 Replies
                1. re: Kajikit

                  We made the jam with my German mother-in-law who has been doing home preserving all summer long for decades. A few jars' lids popped after the flight. I gave the oozing jar to my parents (ha ha) who think it is delicious. We have the ones with the popped lids and are giving them to dear friends, but with warnings to eat it quickly. The popped lids jars are currently in the fridge.

                  1. re: relizabeth

                    Dear friends? Personally I think you should be giving them to people you're not so fussy on :) To tell the truth, if someone presented me with a gift such as yours I'd be tossing it. Sorry but that's just me.

                    1. re: millygirl

                      I feel like that is their decision to make. (These weren't the oozing jars; we gave those to my parents). I picked blackberries, made jam, and transported them 1/3 around the world, and have been 100% honest to them about the lids popping after their transatlantic journey. If they want to bin it, fine. They will be polite friends and wont tell me until years later and after a bottle of wine, and we will all laugh about it.

                      1. re: relizabeth

                        relizabeth, the popped tops/oozing jam is more likely a result of the the transatlantic flight than anything you did wrong in processing (though "the experts" recommend that you never reuse commercial jars, better to use ball jars and new lids).

                        Whenever I've been on long flights, I've noticed that things like toothpaste, creams and lotions, and other viscous cosmetics have a tendency to pop the lids or even explode slightly upon opening. Something do with the the air pressure or pressurization changes due to altitude changes, I think, though I'm no scientist. But since I've had this experience with cosmetics in flight I think it may apply to your jams as well.

                    2. re: relizabeth

                      The hold of the aircraft is not pressurised and heated like the cabin, and even if you carried them onto the plane yourself they still went through a bunch of pressure changes... I'm not surprised that your jam lids 'popped' after the flight - it's nothing to do with how you cooked it, it's from the pressure changes involved in going to that altitude and back down again. If the jam was fine before the flight, it's still fine now.

                      1. re: Kajikit

                        I agree. The transatlantic journey was omitted from the original post and the pressure change, whether in the hold or cabin, is the likely culprit. The impression in the original post is the jars went from processing to storage and some time later the oozing was noticed. The jam is probably perfectly fine to eat if it was given away in a week or so after your return with the caveat that it be eaten right away. If it was stored for any length of time at room temp, say three weeks or longer, I'd be wary of it. I just wouldn't trust the seals. Nor would I leave the decision up to the recipients whether they wanted to play russian roulette with it. If in doubt, dump it. We live in a society that loves litigation and just because they're friends doesn't mean they won't come back at you if you inadvertently poison them whether they were warned or not. I know it's hard to bin something that you spent a lot of time, money, and loving attention on to create but that pales in comparison to making yourself or someone you care about seriously ill.

                        If you are still in that window of opportunity and you have a lot of it but can't consume it all quickly, spoon some out of each jar to leave room for expansion and freeze it. Better yet, turn it into plastic containers made for freezing. Cold temps can crack commercial jars as well. The visual quality will probably not be the same but it will still taste great and you won't have to toss all your work.

                        Do not reuse commercial jars for canning. Those are one time use only jars and are not made to withstand repeated heating and cooling after the first use. I know they're pretty and it seems like a great, green idea to reuse them but not for things that are going to be run through a waterbath or pressure canner with long term shelf storage in mind. Mason, Kerr, and Ball jars are what you want and what's approved by USDA guidlines for home canning. You can use Weck jars with the rubber gasket, clamps and glass lids that look great but they're expensive, difficult to work with, and are not recommended for novice home canners. Paraffin seals are also on the no-no list for unreliability despite still being popular with some folks, as is the method of simply inverting jars, or inverting them in the oven, and not running them through a bath or pressure canner.

                        By all means reuse commercial jars for things you are going to store refrigerated and consume within a short time, or for storing dried products, or for gift giving for immediate consumption with a dated label and instructions of when to consume by. I like them for the left over preserves when I don't have enough to properly fill another canning jar. The leftovers go in the fridge for immediate consumption and it also is great to get an idea of how a preserve is going to taste after it matures for a few days. Sometimes I'll transfer the contents from a sealed canning jar to a pretty commercial jar for table use and ease of storage in the fridge. But please don't use them for actual canning. There's nothing worse than opening your canner to find your jars have shattered and your food wasted, or worse still, the jars have cracked and broken during cooling, made a mess everywhere, and your food's wasted.

                        1. re: morwen

                          I meant to include these links that might be helpful:

                          USDA home canning guides

                          Ball canning:

                          National Center for Home Food Preservation: