Canning 101: Why Pumpkin Butter Can’t Be Canned

pumpkins

This time of year, a canner’s fancy turns to pumpkins. Tis the season for all things round, orange and squashy, after all. However, as you start searching for recipes for home canned pumpkin butter from reputable sources, you’re going to find yourself disappointed. You see, both the USDA and the National Center for Home Food Preservation are going to tell you the same thing. Don’t do it.

I’m sure there are more than a few of you out there saying to yourself, “but I’ve been making and water bath canning pumpkin butter for years!” And it’s true, many years ago, there were USDA-approved recipes for pumpkin butter. Unfortunately, the rules of canning are not a static canon and so, in 1989 the USDA changed their recommendations and the NCHFP followed suit. No home canning for pumpkin butter, not even in a pressure canner.

The reasons why homemade pumpkin butter isn’t recommended are several. When cooked down into a butter, pumpkin flesh becomes quite dense, making it difficult for the heat produced in a canner to penetrate fully through the contents of the jar. This means that even in a pressure canner, the interior of the jar may not reach the 240 degrees needed to kill those pesky botulism spores.

Additionally, pumpkin and all other winter squash are a low-acid vegetables, meaning that without careful treatment, they could potentially be a friendly environment in which botulism spores might grow into their toxic adult state. In tests, it’s been found that the pH of pumpkin has a fairly wide range, meaning that it’s not possible to offer a basic acidification ratio as there is for other borderline and low acid foods.

The good news is that pumpkin butter can be frozen and also keeps quite well in the fridge, so it doesn’t have to be entirely off the menu. I’ve also been pondering whether one could make a an apple-pumpkin butter that would be high enough in acid to be safe for canning, but would contain enough pumpkin to be sufficiently autumnal. I may do a bit of playing around, to see if I can get somewhere close to the flavor I’d like to eat.

If you’re curious to read more about the safety hazards of canning pumpkin butter and other squash purees, click here to download the PDF that was the primary source for this post.

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243 Responses to Canning 101: Why Pumpkin Butter Can’t Be Canned

  1. 101
    kristin says:

    I just wanted to say that I was going to can my pumpkin butter after reading several people on other sites say they’ve done it safely for years. But then I came across your site. I do NOT want to risk anyone’s lives – and especially those of my children – just to can pumpkin butter. I think I will just freeze it now! Thank you so much for your many comments addressing all of the concerns, so helpful. 🙂

  2. 102

    […] a pint of spread. Note that I split that into three jars, though. Squash doesn’t can safely (it’s too low in acid), so cold is its best preserver. I kept one jar in the fridge to enjoy over the next couple weeks, […]

  3. 103
    Hat says:

    Hi!
    I was looking for the official government info on pumpkin canning for a friend and came here knowing you would be the one to have the link to it. You do! But sadly, the link you offer (and everyone else too! ) is dead :-(.
    Has the opinion of our great and wonderful government changed on this topic?

  4. 104
    Sandy says:

    I’m not an experienced canner but I am curious that if you can’t can pumpkin butter then how is it that I was able to purchase it in a jar unrefrigerated at my local Sprouts grocery store? Is that not the same thing just done commercially?

    • 104.1
      Marisa says:

      Commercial canning facilities are able to achieve higher levels of heat and pressure than can be reached at home. That’s how they’re able to preserve those varieties of pumpkin butter that you see in the grocery store.

      • Sandy says:

        Thanks for the quick response! I apologize for my ignorance on the subject (trying to educate myself) but isn’t there some way to get to a higher temperature? What temperature does commercial canning reach? Your info is very helpful!

        • Marisa says:

          There is simply a limit on how much heat and pressure a pressure canner designed for home use can achieve (the top safe temperature is 250F and you don’t want to take a until beyond 18 pounds of pressure). You need more than that to reliably penetrate to the center of a dense puree like pumpkin butter and kill off any present botulism spores. Unfortunately, there’s just no way to safely can pumpkin butter at home.

          • Debra says:

            The pumpkin butter recipe that I have used for years (grandmas) says place all ingredients in a sauce pan .. bring to full rapid boil (240 degrees) pour into hot sterilized jars, put lid on tightly and turn upside down to seal. By the way this article reads it is not suppose to work? I haven’t killed anyone yet ??

            • Marisa says:

              Like the article says, pumpkin butter is a very dense, low acid product and so cannot be safely preserved in the home for shelf stability. Every time you make it the way that you do, you are rolling the dice. Additionally, a full rolling boil only reaches 212 degrees, not 240.

  5. 105

    […] could go through all the reasons why not, but those have been covered exhaustively in the comments in Marisa’s post over on Food in Jars. It really made me laugh. Here’s my version. […]

  6. 106
    Brady McElligott says:

    We can pumpkin in half-pint jars, at fifteen pounds, for about ninety minutes. Since all spoilage, including botulism, creates gases, and none of our jars have broken the seals for several years, and none of us have sickened, we are figuring that we are safe.

    Just how many of us have ancestors that have canned pumpkin/squash, ans have sickened and/or died from canning-borne poisons?

    • 106.1
      Michelle says:

      Certainly everyone is free to do as they wish in their own homes. Personally, the idea that no one has ever died isn’t enough of a safety net for me. Nor is the idea that no one has ever gotten sick. Often people did get sick from canning but it wasn’t diagnosed as such, simply written off as a bad stomach virus. Lastly, fruits and vegetables are different today then the heirloom ones our grandparents and generations prior preserved. They have been ‘bred’ for drought and disease resistance, to produce larger and more desireable crops. This has changed some of the acidity levels. So by all means for your immediate family do as you wish. I think it is only fair before passing these items on to others as gifts, or to consume in your home, you let them know the current recommendations so they can make their own informed decision if they want to consume it. Happy Canning!

      • You handled that well, Michelle. I hope she heeds your advice (here and in the post).

      • Erin says:

        My understanding is that botulism does not necessarily produce gas, and is therefore near impossible to detect. This study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC242325/) states that “gas production is an unreliable indicator of growth and toxin production by C. botulinum”. And as a farmer, I agree with Michelle above that crop characteristics have changed greatly over time due to breeding and selection. That is definitely not to say that we should not trust the wisdom of our grandparents and elders, but that it’s a good idea to check if the science backs up our assumptions. I see a lot of blogs out there with great recipes but with no explanations of their thought processes/assumptions in regard to safety – which is why I use Marissa’s blog as a resource!

  7. 107
    Lynda Gambale says:

    I am curious about doing a 50/50 ratio of pumpkin to apple butter mixture to can in pint sized or smaller jars. Has anyone done this safely? What was your experience?

  8. 108
    Chazz York says:

    Why couldn’t we increase the acidity to a level that would be safe in canning by using citric acid in the puree before canning and boiling the jars. It seems to me that if the pumpkin acidity is too low, the use of Citric acid would even it out without changing the taste in a bad way. Especially since the spices in the pumpkin butter would over power the resulting tangier taste. I understand about the density of the pureed pumpkin, but there has to be a way of doing it safely at home.

  9. 109
    Kassandra Taylor says:

    I want to make the pumpkin butter as a recipe stated and I want to freeze it. Bags are just a mess sometimes. Can I place in a jar and freeze after? Or if not is there another alternative to bags. Thanks for the help 🙂

  10. 110
    Sharon says:

    If you read it says, “When cooked down into a butter, pumpkin flesh becomes quite dense, making it difficult for the heat produced in a canner to penetrate fully through the contents of the jar.” I don’t know if any recipe that actually uses the flesh of a pumpkin.

    • 110.1
      Marisa says:

      All pumpkin butter uses the flesh, the meat, the interior of a pumpkin (or, if it’s not a pumpkin, it’s a winter squash, which has the same issues).

  11. 111
    Michelle says:

    Marisa,
    Thank you for continuing to educate people on the most up to date safety standards. It’s really important to keep current. I love passing on home preserved items to friends and family. I take it very seriously that I only offer things I know are made to the best of my knowledge to be the most up to date standards. Sure, canning can be a fun hobby but it’s also a responsibility. When you know better, you do better. I know I can always count on your website to have current information. Thank you!!

  12. 112
    Kathy says:

    I was wondering after freezing and thawing how long pumpkin butter can stay in your fridge and be used. Should i make ice cubes of it to freeze to keep it minimal.

  13. 113
    Janice Thompson says:

    Thank you, this was very informative. I do have one question for you. I wanted to make pumpkin butter for my daughter who is away in college. I am in California and she is in Massachusetts and Mail takes approximately 2-3 days if I do express. i do not want to chance getting her sick but is there any way you know of to help it make the trip un-refrigerated? I was going to can it until I did some reading and very glad I did. Any suggestions you have would be helpful since I am very new to this.

    • 113.1
      Marisa says:

      There is no way to safely mail pumpkin butter to your daughter. Make her a different preserve, or buy a commercially preserved jar of pumpkin butter.

      • Janice Thompson says:

        I was afraid you would say that! Thank you very much I just made some apple butter and she is super excited. Thanks again

      • Meg says:

        If it were to be frozen in the ball freezer jars and sealed in a plastic zipper bag and shipped in a cooler with dry ice and shipped overnight… It is possible.

  14. 114
    Ginger Wolgemuth says:

    Can I use store bought pumpkin purée as an ingrediate in a canning recipe and be safe?

  15. 115
    jennifer n Mitchell says:

    Wow. I didnt know this was an issue. I bought some from a cottage business and was suprised how different it looked and tasted when i got my jar home. It was nothing like her samples. Thank you for the article.

  16. 116
    Stacy says:

    What does the pH balance have to be?

    • 116.1
      Marisa says:

      With pumpkin butter, it’s not just about pH. It’s also about density. The density of the product is typically such that the heat of the canner cannot penetrate. So even if you get the pH low enough (it would need to be below 4.6), it is still not recommended that you can pumpkin butter.

  17. 117
    Natalie says:

    Hello! I’m making a batch of apple-pumpkin butter using solid-pack pumpkin from a can, NOT fresh pumpkin. Do you think it would be safe to can it in a pressure canner? Curious about whether or not it makes a difference if the pumpkin is fresh (and dangerous to can) or was in a commercial canned state before I used it in my recipe.

    • 117.1
      Marisa says:

      Unfortunately, the density of the pumpkin is the reason why it’s not safe for pressure canning. It doesn’t matter whether you’re using commercial or fresh pumpkin. It’s still not safe.

  18. 118
    Kathy says:

    Any recipe with apples or applesauce mixed in that worked?

  19. 119
    Deb says:

    Glad I found this! THANK YOU!

    I purchased Pumpkin Butter from a farmers’ market a couple of months ago. I stored it on a shelf and just recently got it out. Only NOW did I notice the small type on the bottom of the label that read, “refrigerate.” I wasn’t sure if it meant refrigerate after opening or refrigerate always. I’ve purchased commercial Pumpkin Butter before that was shelf stable, so I was puzzled.

    The lid on this unrefrigerated Pumpkin Butter looks adequately sealed — it doesn’t bulge and it hasn’t popped. BUT I noticed a few small bubbles in the pumpkin butter inside the jar. Those had me worried.

    I’m afraid it could be contaminated with botulism. Is there any way to know?

    Also, should I contact the farmer about it?

    Good to know that pumpkin butter can’t safely be home-canned! Thank you!

    • 119.1
      Marisa says:

      There is no test to determine whether something has botulism or not. That’s why it’s so dangerous.

      I don’t know whether the refrigerate label meant refrigerate all long, or after it was opened. You might reach out to the farmer to be sure.

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