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Jul 29, 2008 09:31 AM

Jam-what am I doing wrong? Will I die?

Ok, this is several questions in one about homemade jam.

My friend gave me some homemade jam about 3 weeks ago. It's one of those big pint jars, which I knew I wouldn't be able to finish, so I asked them to give me the jar that they already partly used up.

They canned the jars, did the sterilization process, etc. etc.

This morning, I had some with my yogurt, and I noticed after the fact that one of the areas had already developed mold. Ugh.

So my questions (since I can never seem to finish a jar of jam without it molding)
1. Will I die from botulism from this morning's experience?
2. The mold typically grows on areas of jam that are either stuck on the walls, etc. Maybe I missed this, since we never really did this while growing up, but am I supposed to meticulously scrape off any remnants of jam off the walls of my jars every time I have jam?
3. I hate wasting food, but I hate the idea of dying from botulism even more. :) Can I just discard the area that was contaminated with mold and then proceed using the other uncontaminated areas?
4. I don't think my jam-eating rate is that ridiculously slow, but all of the homemade jams I've ever received (except this one plum jam that I receive from my friend every year) have never lasted more than a month or two before it starts to mold. Is there a way to prevent this? I just made pint-sized containers of apricot jam, and I'm afraid to open it lest it start to mold before I manage to finish it all.

FYI, these are full-on sugared jams.

Thanks much.

The Jam Idiot

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  1. Can't answer all your questions but I just scrape the moldy parts off the lid or sides of the jar and eat what isn't moldy. Still here and healthy.

    It's not that onerous a process. A quick wipe with a paper towel or scrape with a spoon is all I ever do. Done in seconds.

    1 Reply
    1. re: three of us

      Great. Now I know I can eat around the mold (kindof like cheese. Heh heh). Actually, I ate my mold-contaminated jam yesterday and I'm fine, so I guess it's ok.


    2. My homemade jam lasts a lot longer than that. Do you keep it in the fridge? It also helps if you always use a clean spoon to put it on your toast, rather than using the knive you've used to spread it with, ifyswim.

      3 Replies
      1. re: greedygirl

        Absolutely. I mean, heck, I even refrigerate tomatoes (I know that's sacrilege, but my apt. gets really hot during the day, so if I can't eat them before they start getting soft, in they go.) And I always use a clean spoon. . ..

        Maybe I should start freezing it.

        1. re: anzu

          Refrigerating tomatoes permanently kills the tomato flavor molecule, Z-3 hexenal. Put them in the coolest place you can find that's not the frig -- in a bowl or plastic container in a deep drawer, or someplace cool and cover them with a towel. You should get some extra days of life this way. Just don't refrigerate them -- that's tomatocide.

          1. re: anzu

            I make jams when fruits are abundant and use very little sugar. They've kept pretty well by using clean utensils and storing in small jars. And, *gasp* I have frozen them with no harm done for 6 months or so (when it got eaten up, not thrown away). So by all means, freeze away.

        2. I always scraped mould off homemade jam and haven't died yet!

          1. Botulism is mainly a risk with low-acid (high-pH) foods such as canned vegetables. Acid and sugar retard the growth of bacteria. According to the CDC (, "Foodborne botulism has often been from home-canned foods with low acid content, such as asparagus, green beans, beets and corn. However, outbreaks of botulism from more unusual sources such as chopped garlic in oil, chile peppers, tomatoes, carrot juice, improperly handled baked potatoes wrapped in aluminum foil, and home-canned or fermented fish." No mention of jam.

   ( says:

            "If I find mold growing inside a jar of canned food, can I just scrape it off and eat the food?

            Mold growth in foods can raise the pH of the food. In home canned products, this could mean that the high acid products could become low acid and therefore run the risk of botulism or other bacterial spoilage. Thus, any home canned product that shows signs of mold growth should be discarded. The exception to this is jellied products. (where sugar is added). In these the high sugar content would prevent the growth of Clostridium botulinum. In jellied products, remove any surface mold plus 1/2 inch of the good product underneath and then use the rest immediately. Jellied products with extensive mold should be discarded."

            1. Also, I think jam with a lower sugar content goes mouldy more easily, but I could be wrong.

              2 Replies
              1. re: greedygirl

                I think you've hit it. Sugar is a preservative. Whenever I make jam, I'm ever so slightly tempted to skimp on the sugar. I think something in my brain goes "but it will be healthier that way!" Silly, I know. But I've never acted on that. It's the sugar (usually fruit:sugar ratio about 1:1 in weight) that keeps the fruit from spoiling. I wonder if other people making jam use less sugar than necessary.

                I also usually use a bit of lemon juice. It can perk up fruit that's not so flavorful, and plus I figure the extra acid can't hurt in terms of preserving.

                By the way, I don't keep my jams in the fridge, and I don't scrape the bits from the sides of the jar. Have never had mold.

                1. re: Kagey

                  I make low sugar jam every summer (nowhere near 1:1 ratio) and I don't have a problem with spoilage. (I have less-sweet, more fruit jam and the color doesn't keep as well. I always add lemon.) Usually an open jar of jam in my fridge is gone in about 2 months.

                  I can't imagine scraping mold off my jam and eating it. I'm sure it wouldn't kill me, but YUCK.