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Jul 27, 2010 07:33 PM

Storing cans of maple syrup - weird crystals on the bottom?

I just opened a can of maple syrup and it has clear crystals on the bottom. I have opened cans from this case in the past couple of months and not found this before. So, am I storing it improperly? It's in the basement in our storage pantry but the case is on the floor. I think it's still okay to consume, unless anyone tells me differently! I'd love some comments and advice. Thanks in advance.

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  1. It's just the sugar crystalizing. The same thing happens to honey although with honey, heating the jar in simmering water seems to dissolve it. When I tried the same thing with some maple syrup that crystalized I didn't have any luck with heating it.

    There must be some maple syrup experts out there that have more information on this subject.

    1 Reply
    1. re: John E.

      I make my own from a couple of trees out front. When a batch from last week crystallized in the fridge , I just poured it into another pot of boiling sap. In other words, it's a matter of dilution - add h2o and boil.

    2. Maple syrup is a highly saturated sugar (sucrose, glucose and frutose) solution and will develop crystals over time; that's what you have. This crystallization occurs from syrup that has too high a density. Maybe your syrup producer didn't do a proper Brix test on your syrup, or maybe the syrup was not brought to the correct temperature that is critical for producing quality syrup that stores well. Anyway, it's no big deal, perfectly fine to eat. If you reheat the syrup to melt the crystals, you risk concentrating the syrup further, so don't bother. Just ignore the crystals. How much syrup do you have?

      If you want to check your syrup, get a brix refractometer and test it; the density should be at least 66% solids, up to 67% to 67.5%; anything lower than 66% is not legally maple syrup and anything above 67.5% means crystals will form in the storage container.

      Sealed containers should be stored in a cool, dry place and have about a one year shelf life. If you have a big supply, freeze it; although the syrup won't freeze, but freezing will keep it from decaying in flavor or molding on the top of the container. Opened containers should be refrigerated.

      9 Replies
      1. re: bushwickgirl

        I had maple syrup that molded on me once, so sad. Now it's always refrigerated after opening. Maybe you could scoop out the crystals and eat them like maple sugar candy?

        1. re: coll

          My daughter used to do that. It is like maple syrup rock candy.

          1. re: coll

            Yep - real maple syrup (of course, vastly different from the fake crap) will go bad if not stored properly. Usually it says something like "keep refrigerated" on the bottle.

            1. re: coll

              That's normal. Just remove the mold, the rest of the syrup is still fine.

              1. re: sonia darrow

                OK I hate to admit it, but I had company staying over at the time so I DID remove the mold and put it out on the table, and then threw out afterwards. We lived in the boondocks then so couldn't run out for more. This was maybe 25 years ago and we're all still around, but I was younger and a lot more carefree then. Now I always refrigerate so I don't have to decide one way or another. Live and learn!

                1. re: sonia darrow

                  "That's normal. Just remove the mold, the rest of the syrup is still fine."

                  Sorry - that's not true. The syrup will still taste OK - but it is possibly full of carcinogenic toxins that just add to your 'total' until someday someone yells 'Bingo' - and you won't be a winner.

                  I did a lot of questioning on this and eg advice given by Cornell University people is to definitely dispose of moldy syrup. The exact nature of the consequences is not totally known but there is no reason to play with fire.

                2. re: coll

                  Even in the fridge it can mold. The Maple Syrup Cookbook advises straining through cheesecloth, then bringing the syrup to a boil before pouring it into a clean container.

                  For crystals, it recommends putting the container into a pan of very hot water until they dissolve.

                  1. re: greygarious

                    Good to know, next time I'll strain it and boil. Too expensive to throw away. But it only happened that one time, we had just moved and I left it stored in the pantry, now always in the fridge and never a problem again. If I ever got crystals I'd be very tempted to fish them out and snack on them though.

                    1. re: greygarious

                      "putting the container into a pan of very hot water"

                      From my experience with homemade maple syrup that had crystalized, the hot water method takes days to work. Really, just forget about them or do like cool does, fish them out and snack on them.

                3. Thanks everyone for the input. I was pretty sure it was safe, but figured no harm in asking. I'll see if the next can has the same thing before I complain.

                  1. The original comment has been removed
                    1. If there are no signs of mold, it is perfectly safe. The syrup was saturated at a certain temperature when closed and also basically saturated. It has been probably stored at a somewhat lower temperature and you've gotten crystallization.

                      On opening now - the remainder after first use (if any) should be stored in the fridge.