Canning 101: Why You Shouldn’t Can Like Your Grandmother Did


When I first started canning in earnest, every few months, I’d wrap up a collection of full jars and ship them off to my parents. I just couldn’t resist sharing all the delicious things I was making with them. One evening, my dad took a moment to call and thank me for the orange marmalade I had recently sent his way. During that phone call, he also made a request. Could I possibly make grape jelly sealed with paraffin wax, like his Grandma Bartlett used to make?

I adore my dad and am nearly always willing to go pretty darn far out of my way to do something to make him happy. Sadly, this was one request that I had to turn down. The reason? It’s just not safe to do it the way Grandma Bartlett used to do it.

Some of the vintage techniques you should avoid include:

Open Kettle Canning: This is the sealing method in which you pour hot jam, jelly or other preserves into a hot jar, quickly wipe the rim and apply the lids and rings. Then you simply allow the heat of the product to produce a seal. While this will typically produce a seal, you don’t have the back-up of the boiling water process, which means that you run a higher risk developing mold or other bacteria in your preserves.

Paraffin Wax Seals: The method my father remembers so fondly. In this technique, you pour thin layers of wax over your jam, until you built up about 1/2 an inch of wax on top of your product. The primary issue with this method is that there’s no way to check your seal. Additionally, these seals have a high rate of failure. My mother remembers her aunt frequently opening jellies sealed in this manner, only to discover that they were furry with mold under the wax.

Upside Down Sealing: This is sealing method found most often in Europe and is a variation on the Open Kettle approach. In it, you fill your jars, wipe rims, apply lids and rings and then, instead of processing you invert the jars and cover with a kitchen towel until they’re cool. While this technique will give you a concave lid and a fairly firm lid, it does not always produce a quality seal (and again, you lack the safety insurance that the boiling water process grants you). Additionally, if you do this with a firm setting jam or jelly, you’ll end up setting your jam up against your lid and not down at the bottom of the jar where it should be.

Steam Canners: A steam canner is a piece of equipment that looks like a cake carrier. It has a very shallow base with a high domed lid. You place it on the stove, pour a small amount of water into the shallow pan, put your jars on top and then cover with the domed lid. The steam then circulates to heat the jars. However, while steam can be hotter than boiling water, it can also exist at much lower temperatures as well. Additionally, it doesn’t have the same heat penetrating abilities as boiling water, so the heat of the processing pot will not penetrate to the core of your jars.

The way I look at canning is this. We all invest our time, money and equipment into our canned goods. It just makes good sense to use the most reliable processing techniques available, to ensure the best outcome possible. As far as I know, the most reliable process (for high acid foods) is a boiling water bath for the length of time prescribed by your recipe.

I think even Grandma Bartlett would change her ways if she was canning in the 21st century.

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97 Responses to Canning 101: Why You Shouldn’t Can Like Your Grandmother Did

  1. 51
    hope says:

    I am still learning the canning methods…on my own as my grandmother always said ” I dont remember” lol so I started with a few books and then continued my search online. The problem IS that after all those books and all those sites….I seriously feel more confused that when I started lol All seem to have their own ways. I have done “open kettle” method and I have done “water bath” method a few times. I have no pressure canner YET. Anyhow, here is the question……what is really considered a water bath??? What I am asking IS at what temperature does the water in the pot need to be and how do u keep track of that temperature? I ask as last year I tried the water bath method with pickles…….it was a total flop. All of my lids did in fact stay in tact with the jars and the pickles all appeared to look fine through the jars BUT the issue seemed to be that bathing them in that water made all the pickles so soft and squishy that I ended up throwing all of them out. So I have been really trying to figure out the proper way to water bath them without boiling them to death resulting in squishy pickles that we wont eat anyhow lol I thought I was avoiding making us sick but in the end I lost out on money and time :(

    • 51.1

      The water bath canner isn’t about temperatures. It is the boiling water that is important. Since water boils at 212* F, then I assume that would be the temperature, though I’ve never tested that opinion. I do know that when the water is boiling is when you start timing the process, not when it is at a certain temperature. That being said, it doesn’t have to be at the hottest setting to boil, so maybe your stove was set too high and was boiling hotter than it may have at a lower setting?

      I had the same result with pickles the first year I tried them, and again the second time I tried them. After that second time I decided to focus on something else beside pickles for a while. Mine too were not eaten, and it felt like such a waste of time and effort. Not what you are wanting to hear, I know. Perhaps someone who is great at pickles can speak up and give you some pointers. I’m pretty sure my failure had to do with something else along the way – maybe my time was off, the pickles were too mature, let them sit in the brine too long, etc. I’m just not sure what when wrong for me, and haven’t been able to take the time to figure it out yet. I moved on to different jams/jellies and tomatoes.

      • Scott says:

        There is a product called pickle crisp, made by Jardin (Mason, Bernardin parent co.). It replaces pickling lime, which shouldn’t be used now. Works quite well.

        • Lindsay says:

          ‘Pickle crisp’ is unnecessary. I did a test a few years ago – with and without – and it made no difference at all. Except the ones with the pickle crisp had a funny aftertaste in my opinion.

          Since pickles are by definition canned in vinegar, you don’t have to worry about botulinum toxin. Choose a recipe with boiling liquid poured over room temperature cucumbers in hot sterlised jars (open kettle canning) and then seal them.

          The boiling water bath method is useful to make sure ingredients are at a temperature to kill any bacteria, but just ends up ‘cooking’ your pickles and making them soft.

          The ‘pickle crisp’ is also often pushed as ‘the same ingredient in commercially produced pickles’. Not in the pickles I buy!

          • Lindsay says:

            Sorry, forgot to add that you should wash the pickles and then nip off the blossom end of the cucumbers before using them. This is often where most bacteria occur.

            • Linda says:

              Is it possible to do peaches and pears without the water bath to?? I canned with a Morman lady one year and she showed me to put the fruit in hot sterile jars pour in boiling water and a drizzel of honey then seal. We ate them all winter and no one got sick. Was it just luck? People tell me they have to go in the water bath.

    • 51.2
      Stargazer says:

      My mom learned from her mother how to make refrigerator bread and butter pickles. She has a very simple recipe that does not require cooking the pickles. She does not use a water bath canner or any type of heating method, and the pickles are great, do not get moldy, do not go off, etc. They go into the ‘fridge for storage and last until they are eaten, regardless of how many jars she makes.

  2. 52

    […] Why You Shouldn’t Can Like Your Grandmother Did @ FoodinJars […]

  3. 53
    Karen Alvstad says:

    I got a pressure canner for the first time this year especially to do green beans. I have done much water bath canning but never pressure canning. As I was reading your post about canning like your Grandmother did, I had to smile. As I canned yesterday in my air conditioned house when it was 93 degrees outside, I couldn’t help but wonder how my mother, grandmother and great grandmother survived the canning seasons with no AC, and not even a fan. Sometimes those women had what they called summer kitchens, but yesterday it would not have been bearable to be in one of those either. And how did they keep the flies out of those summer kitchens? We certainly have it good by comparison; and we choose to can. We don’t can out of necessity.

  4. 54
    Fred says:

    I have used Wax Seals for years and don’t have that problem. I don’t know what you’re doing to make it go bad.

    • 54.1
      Marisa says:

      Wax seals are not recommended by the USDA.

      • Michael says:

        Neither is drinking raw milk. The USDA (just like canning companies) establish rules based on easiest idiot-proof safety. As an example, the date on a can is the date the company is willing to own the risk until. After that date, you are eating your own risk. If you want or need to operate like this that is fine, but you risk missing out on other sweeter things. If you abandon USDA protocol, you definitely risk, but the onus (and potential rewards) are all on you. When you make things yourself, the more careful (anal) you are about things, the better and safer the result. If you are new to this world though, I would definitely harken to Marisa’s warning.

    • 54.2
      Earlene says:

      I have always used wax seals for my jellies, never had a problem.

  5. 55

    […] into the jar, seal it up, flip it over on it’s top, and let them sit a while.  Here’s some more options.  So much easier, yes, but terrifying for me.  Here’s the short version of […]

  6. 56
    Lindsay says:

    Hmm. All the newer canning books say these same things. And yet, my mother, grandparents and aunts all canned using the ‘open kettle canning’ method you describe and I don’t remember a single instance of mould or ever having to throw out a jar. I don’t see even the potential for problems – hot dishwasher cycle, boiling water in the jars and on the lids, sterilised cloths, and the lid seals. There’s not much room for error there unless you don’t understand what ‘sterile’ means or have a filthy kitchen.

    I have used this method for the last 15 years myself and never had a single problem. I’ve also taught this method to many ‘newbie’ canners and they’ve never reported any problems. I believe the issue is when it’s not done properly, which is probably pretty easy if people are stupid or lazy.

    The only time I every use a boiling water bath is when it’s something like tomatoes and since you can’t smell or see the bacteria that produce botulinum, I take every precaution.

    I think it’s people spreading all this fear that prevents so many from canning their own food. And I think there’s potential for a large debate over whether the crap from the supermarket shelf is ‘safer’ to eat.

    • 56.1
      Joyce says:

      Lindsay…can you e-mail me. I have been looking for someone who cans like my family canned when I was growing up. I have some questions. Thanks! Joyce

    • 56.2
      Louise says:

      I have no problem with the BWB, which isn’t hard at all, really, and takes away any doubt about my ability to properly sterilize jars and lids. That said, my problem is that when you BWB marmalade the heat makes the marmalade thin again, and the fruit floats to the top. Any advice how to prevent this? Using both the temperature and frozen plate tests my marmalade will set up fine–but it’s still warm and I’m looking at the floating fruit and wondering if there’s any solution.

    • 56.3
      Carolyn says:

      I agree completely. I’ve been using open kettle canning for 40 years as did my mother, her sisters, and my grandmothers. The jars are very hot, the contents are very hot, and I work quickly. If a jar doesn’t seal, it’s obvious and handled appropriately. It’s never caused an issue for any of us. I used parafin for jelly for many years and rarely had one go bad; when it leaked it was obvious. And I agree with the statement about spreading fear, it’s paralyzing people to the point they become afraid to do anything for themselves, or think on their own. Personal responsibility is a very good thing in all aspects of our lives. And yes, I drink raw milk too, as did all the people that came before me. Mom is 94, grandma was 104. I think we’ve made good choices.

    • 56.4
      Sue says:

      Hi Linsay, .. love your post, thank you.. I am so confused after reading too many sites about what to do and what not to do…. I also agree about questioning what’s safe with things we buy in the super markets today.. oy vey! My Mom used the wax method for jams and jellies with no problems ever and also I remember her turning jars upside down for other things… she also heated jars in the oven before using them… can you please shoot me your email address too … I also have some questions… thanks!
      Marisa, thanks for a great website with some super info.

  7. 57
    Connie says:

    I have been reading up on canning, and came across this site. I live in the desert, and have an abundance of “prickly pear cacti” …. recently touted on infomercials as the Nopal cactus. They are free and the birds eat every one of them, very quickly. So, I decided I wanted to try my hand at canning, and make some “southwestern cactus jelly” to send back east to family for Christmas. I’ve never canned, but have watched my mother and brother do it. They used the “cold pack” method, where they fill the jars with cold food, and then pressure can them. (I think the directions for this are in the canner instructions.) They used the paraffin method to seal the jellies. And they used the “hot bath” method, where they filled the hot jars with boiling food, sealed them quickly, and processed them in a pan of hot water. Mom said that the wax is good for jellies, but not really safe for other foods. The hot bath was good for things like soup, with or without meat. But the pressure canner was really the best option for anyone who has access to a canner and isn’t afraid that it will “blow the roof off the house.” I’ve used pressure cookers to make many meals, so if I can find a larger pressure canner, I believe I’d rather go that route, just to be sure. Why take unnecessary chances? That being said, it’s really a good idea to be familiar with all the different canning methods, so that you are ready to can whatever is available with whatever canning equipment you have on hand. Canning is something that all “preppers” should familiarize themselves with. So, I’m off to look for pressure canners, because the cactus fruit will soon start to ripen and I don’t want to miss them. Happy Canning, everyone!! :D

    • 57.1
      Marisa says:

      The information your mom gave you is not particularly good. You don’t use paraffin wax for anything these days. You should use a pressure canner for all low acid foods, including soups, stews, stocks and vegetables. You can process high acid jams and jellies in the boiling water bath canner. Please do your research before you start canning!

    • 57.2
      Phil C. says:

      Pressure canning equipment will not “blow the roof off the house” if it is kept in good repair. With bad seals, they’ll simply never develop pressure, so in that sense they’re no more dangerous than an open pot of boiling water. As long as nobody has disabled or modified the pressure relief valve or stopper, the body and lid of a pressure canner will withstand several times the working pressure, by design, so there is a wide margin of safety.

  8. 58
    Rachel says:

    what about open kettle canning or invert and seal method for fruit or fruit pulp without any sugar or preservative?

    • 58.1
      Marisa says:

      I do not recommend open kettle canning or the inversion method, particularly for fruit products without any sugar. Sugar is a preservative and those products will succumb to mold much faster when not done in a boiling water bath.

      • Charlene says:

        We did the inversion method with a pear tree we had in our front yard. 10 years later I found a can I had given my mother-in-law still with no mold or any issues whatsoever!

  9. 59
    vddillard says:

    Diane, I need to know about blackberry jam after it has been sealed and after a few weeks you opened it and there is mold on top of the jam is it safe to eat.

  10. 60
    Lynda says:

    I am a Canadian living in Croatia…. no access to lids and rings. So what do I do now? All I can find are jars and all-in-one twist on lids. Thanks


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