What's the best way to preserve a Jack O'Lantern?


My kids and I are carving Jack O'Lanterns today. This year, I didn't want them turing into saggy mold farms, so I went online for a solution. One of the top hits was Cory's post from 2006, What's the best way to preserve a Jack O'Lantern?


    1. Clorox Cleanup sounds like a way to make an expensive product out of 89 cents of gallon bleach.

      I think I’d want to try sodium benzoate or sodium propionate, or both. Since I don’t really have access to those I would try a solution of boric acid or borax to retard mold growth.

      If you use bleach please don’t make your solution stronger than 200 ppm.
      I believe that’s a shot glass or so per gallon of water. Making the solution too strong doesn’t improve its antimicrobial activity but does increase the hazards of using it. That stuff is one of the most misused and overused checicals.

      It never was an issue in Wisconsin. Our pumpkins always lasted.

  1. I have always used petroleum jelly on all cut edges, to keep it from drying out. (insert dirty joke here)

  2. We usually wait till the last week to carve ours. That way they last through Halloween and a few days after. Part of our kids enjoyment of Jackolanterns stems from watching the squirrels go to town on them afterwards. Not sure the squirrels would enjoy the pumpkins as much if they were coated with vaseline or white glue.

  3. I was going to say – just wait to carve them until the 29th or 30th.

    We buy smaller, tasty pumpkins from the farmers’ market, rather than the huge, bland ones from most grocery stores, so that they’re worth eating after they’ve held a candle for a night.

    Any method of preserving them outdoors for two weeks would ruin them, as food. Somehow, pumpkin-and-vaseline pie just doesn’t tempt me much.

  4. How expensive is bulk cyanoacrylate? I remember reading it was at one point sold in an aerosol spray can. Maybe try to treat it with lemon, ascorbic acid, or vinegar first to prevent oxidization.

    1. Bulk cyanoacrylate… I think that runs around $200-$300 per liter (or per quart). Not cost effective and nasty fumes.

  5. We used to just carve like, 2 days before, and chuck them into the garden clippings bucket the day after…. problem solved.

    Also, MyScienceProject did a study on containers for trick or treating, but they did not take into account my methods as a child. I always picked a receptacle that matched my costume, then made Dad hold the pillow case, and periodically dumping some candy into it. Thus, I did not have to carry as much, and the later houses thought I had gotten a late start, and didn’t have much candy, generally upping the amount of candy per house. Deliciously devious.

  6. I once sprayed one thoroughly with a silicone lacquer meant to be used as a conformal coating for circuit boards. That one lasted a long time, but I’ve never used any of the other methods so I couldn’t say how it compares.

  7. It probably depends on where you live. Here in the coastal part of the southeast USA, jack-o-lanterns mold within two days and it is best to cut them on Halloween or the day before at the earliest and put them on the compost pile on November 1st.
    Usually two days post-cutting you will find an oozy gnarly mess underneath and a nice fuzzy coating of mold blooming inside because of the humidity. I guess you could refrigerate a cut Jack-o-lantern to keep it around longer if you have room in your fridge.
    I love to look out the window each day after Halloween and watch the gradual collapse of my Jack-o-lanterns into my compost pile. Their ephemeral nature seems totally in keeping with the “holiday spirit” of Halloween, IMHO.

  8. …and of course, for ultimate longevity…
    Make a plaster cast of the thing and make a permanent replica.

    Or just let it rot.

  9. Spraying/brushing with lemon juice helps to preserve a pumpkin really well. I thought this was common knowledge and was surprised to not see it included in the experiment.

    1. I wouldn’t have thought of lemon juice, but it keeps apples and pears from oxidizing once they’re cut.

  10. Go the histological route. Fix with formaldehyde, then go through graduated ethanol (70%, 95%, 100%) to xylene. Then xylene/paraffin to molten paraffin. Once the paraffin cools, that Jack will last forever. For little pieces of tissue, say 0.5 cm^3, each step would be a few hours. For a pumpkin, maybe a few weeks to a month per step. Maybe you could stop at the 100% EtOH, and dry it to make a shrunken head. That would be cool.

    Or maybe just take a picture.

  11. Why would you attempt to use toxic things like formaldehyde?

    I’d be inclined to use common food storage methods, like the brine solution already mentioned. All kinds of food have been stored in vinegar and oil.

    But I suspect unless you actually submerge the pumpkin in brine, oil or vinegar, the oxygen and bacteria will start doing what they’ve been doing since bacteria came into being.

  12. Take a picture, it might last longer.
    It’s a pumpkin. You carve it a day or two before, light it halloween night, if some punk doesn’t kick it in and it’s still there the next morning- you win! The End. Throw it out, or throw it in the bushed out back.
    Keeping a pumpkin alive for two weeks- that’s like putting up the Christmas tree before the 12th (minimum!) and leaving it up after the new year.

  13. Try putting it in the refrigerator with a wet paper towel over it. It worked for an extra day or 2 out of it.

  14. Note that none of the methods listed in that article are environmentally-sound, and they will not allow your pumpkin to biodegrade naturally. You will have to throw your pumpkin away in a landfill, and not in the compost bin to feed the garden you talk about in your book.

    Just delay pleasure a little, don’t cut them yet, and appreciate them as they age and change, and eventually compost them. Or, if your kids simply must cut them now, accept that they won’t last and cut more the night before halloween like everyone else.

    1. A little bit of bleach or vaseline in your compost will do no harm… unless your scared of the fluoride in tap water and vaccinations too, then it’s terribly deadly.

  15. Carve out as much of the inside as you can, and use it to make pie. Expect the rest of the pumpkin to be transitory, and enjoy it.

    Or don’t carve the pumpkin, just paint the face on the outside with black paint. Then you can let the pumpkin last a long time, like they normally do, unless of course the squirrels or the neighborhood kids get it.

  16. 1) Remove seeds and connecting tissue and place in canopic jars.
    2) Pack carcass with natron.
    3) Wrap pumpkin with thin strips of white linen.

      1. Ensure SOMEONE ELSE reads from the great book Pumkinomnicon, then steal their treasure after the Gret Pumpkin snuffs them.

  17. What I used to do was put them in a chest freezer and freeze them rock solid after carving. They would be outside on display for about 12 hours per day and, on average, I could keep a dozen pumpkins 100% intact for up to a month.

  18. Here’s a slow and a fast method I’ve learned from a dried bouquet maker:

    First you’d want to dry it out, just like a mummy.
    So, scoop out it’s guts – just like a mummy – and let it dry out in a dry place, suitable to dry herbs and flowers (or mummies).
    This can take weeks, even months, except if you live in a sand or salt desert area.

    Speed up the drying process by placing the pumpkin “bowl” in the microwave, without it’s top.
    Nuke it so the moisture heats up, but don’t cook it.
    Once cooked nothing can preserve your pumpkin! – so experiment.
    While cooling (in a dry room) the nuked pumpkin will lose much moisture fast. You can see it misting out, shaving months of the drying time.

    Instead of drying the scooped out pumpkin in a dry room, you can bury it in table salt, a month or even a whole year before. Brush the salt off the outside before cutting.

    Cut the leathery dry pumpkin into it’s desired shape with a bloody sharp knife. Now varnish it. The varnish will creep into the dried pumpkin tissue, preserving it from the inside.
    Let the varnish dry and it will keep forever.

    Happy – next year’s – halloween!

  19. another idea, gut it, cut it, freeze dry it. I did some inspections at a freeze dry facility it was a simple process.
    1-frozen food was loaded onto trays
    2-chamber sealed and air pumped to very low pressure
    3-temp was allowed to rise from freezing to about 50-80C over something like 24 hours
    4-open chamber and package foods in airtight bags
    I imagine making the chamber wouldn’t be too difficult but getting a good vacuum pump probably would. Maybe an electric tire pump placed in the chamber with the food pumping the air out would be enough although motor cooling might be an issue once the pressure drops.

  20. Soaking a carved pumpkin in a container of water a few days later will extend the life considerably. Avoid frost, it will do bad things to pumpkins.

  21. Thinking of a t-shirt: THIS PUMPKIN WILL BE A FETID PILE OF MOLD

    I don’t understand the obsession with hording the dead. Jack-o-lanterns should be composted so they can become new generations of pumpkins. It’s the circle of life, not the one way street to death.

    Death is not an end; it is the start of a new beginning.

    I am a hypocrite – I collect mounted insects.

  22. I found that living just below the Arctic Circle kept my pumpkins freshest, longest – ’til April or May, usually.

  23. I never sought to keep a pumpkin around more than a couple of days. I do some pretty fine carving (“fine” as in small and detailed, not “fine” as in particularly good), and those details are the first to degrade, usually within 24 hours in my SoCal experience.

    Maybe my wicks are too long, though that’s *not* what she said. Alas.

  24. I’d be interested to see what the effect of burning a candle continuously in the pumpkin would be. On one hand, the interior of the pumpkin would be warmer, tending to increase the rate of decay, while on the other hand the soot might tend to discourage mold growth.

  25. While the outside of the pumpkin wrinkles a bit around the cut edges naturally, I have successfully killed the mold inside the pumpkin by spraying it with Lysol. I wouldn’t expect the pumpkin to last much more than two or three days longer with this, though.

  26. I’ve heard that if you pee on it once a day, it won’t decay as quickly. Plus, it puts the candle out when you go to bed for the night so by next evening it’s fresh, dry, and ready. Would recommend a scented candle or maybe even a citronella.

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