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

August 4, 2010(updated on October 3, 2018)


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. In 2016, Atmospheric Steam Canners were approved for home use. More info here.

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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137 thoughts on "Canning 101: Why You Shouldn’t Can Like Your Grandmother Did"

  • Confession time. When it comes to jam, and jams alone, I totally do the open kettle method. And in over 10 years of canning on my own I’ve only ever had 1 jar go bad.

    1. Cheryl, sounds like you’ve had a long streak of good luck! My mom used to be a open kettle person herself, until an entire batch of apple butter molded within weeks of sealing.

      1. My grandmother used to seal with the open kettle method. I don’t know what her success/failure rate was, but we recently opened a jar of 30 year old green beans and ate them for supper. Very delicious and fresh!

        1. I dearly hope those green beans were pickled or canned in a pressure canner. Otherwise they are decidedly unsafe.

  • you forgot the oven canning method as another one of grandma’s old tricks.. you fill the jars then bake them in the oven for X amount of time.. I have an old ‘oven caning guide’ for my vintage stove. not planning on using it, but thought I’d mention yet another method that has gone by the wayside over the years.

  • I was hoping you’d have something to say about pressure canning in this post. Anything? I’m pretty new to canning, and started using a water bath, but I got this great pressure cooker with canning kit and have been using that since. It seems to work well. Is there anything I should know about safety issues with pressure canning?

    1. Jill, pressure canning is a fantastic technique for canning low acid foods like vegetables, stocks and beans. I was only writing about high acid canning techniques in this post, which is why I didn’t mention it. However, stay tuned for some pressure canning info coming soon.

  • My grandma used the paraffin method and open canning method in all her canning – her tomatoes, jam, and corn relish were always a 50/50 for mold. I would kill for her old Swedish steam juicer, she made the most delicious blackberry juice with it. I’ve tried and tried to duplicate it, but that old steam juicer was the magic touch.

  • Thanks for posting this, Marisa. With so many new canners it’s critical that they start with the proper and safe *modern* methods.

    I hope you’ll do a canning 101 on why to use the proper method for your canning: boiling water bath for high-acid foods and pressure-canning for low-acid ones. I’ve read so many comments online over the years that went along the lines of “My grandma canned green beans in boiling water and nobody ever got sick, so I do it, too” that I want to scream.

    We put so much time, effort, energy, and love into our canning, doesn’t it make sense to follow proper modern techniques with knowledge that wasn’t available to our grandmothers and ensure our families’ health?

    1. Jenn, that’s my feeling exactly. Just because the old techniques work doesn’t necessarily make the best or most safe.

      1. I’ve heard that to process green beans in a boiling water bath canner years ago it took 4-41/2 hours not to mention all the heat and energy used….give me a pressure cooker and 30 min anyday…rightfully so people were afraid of pressure cookers back then …they were molded/ made from 2 pieces….today they are machined from one piece of metal

  • The oven-processing method mentioned by Katyo actually hasn’t gone by the wayside. I know canning pros who use it. I use only the water-bath method, but I’m curious, Marisa, whether you have an opinion on sterilizing and processing jars in the oven.

    Nice post. Cute jar! πŸ™‚

    1. Shae, I don’t use the oven techniques (primarily because my oven is tiny and it would take a lot of disassembling to make a tray of jars fit) but I do believe they work. I also believe that you have to know what you’re doing in order to use that approach, and so for beginning canners, I don’t think it’s the best.

  • thank you thank you thank you again – for stressing safety and giving the reasons why some ‘old-fashioned’ methods just shouldn’t be used. No one’s health is worth the risk. Kudos!

  • Me and my family has done the open kettle method for more than 60 years now and I don’t recall one single jar that has gone bad. If you pay attention to the quality of fruits and work accurately I don’t see any problems with this method. Maybe Europeans are not as hypersensitive when it comes to food safety πŸ˜‰

    1. I wonder if it has to do with where one lives. In Hawaii, stuff molds fast…I wonder if Digital Duchess isn’t also from a humid area where you can’t leave bread on the counter, or it molds. When I lived in Paris, food didn’t rot as fast.

  • Open kettle: It’s basically all I do. I can’t get a pan deep enough to cover reasonable-sized jars to do water-bath. In addition, open kettle jam and chutney is what we still do in Scotland and no ill effects. I’ve just opened a jar of jam from 2005- granted it isn’t at it’s best ;0) but perfectly edible. IF I did have a deep pan I’dd do more canning of veges and things, but I’d still open kettle jam.
    Love your blog.

    1. I bet as long as the liquid in the jar is boiling after the water bath, it’s fine for high acid foods anyway.

  • Nice summary of a few major bad ideas. When I started canning, parrafin was still pretty common for jam – I remember picking the waxy bits off the jam and being annoyed about having to give up even that tiny bit. What is surprising to me is that many writers, including some pretty influential bloggers, are still recommending some of those methods. I cringe every time I see it.

  • I found a canning book in a used book store one time and it had things with pasta and other no no’s in it for canning.

  • Katyo – sounds like you have never read a book on canning. You SHOULD NOT be canning without having read a book. Period. This is a great website, and Marisa knows her stuff, but I’m sure she’d agree with me that it should not be your only resource.

    The USDA Home Canning Guide is a good free book that will tell you all you need to know.

    Hint : pressure canning is SAFER than boiling water. But READ THE BOOK!

  • p.s. another one I’ve seen – a friend saw this on a TV show a few years ago – is canning in the dishwasher! YIKES! Run away, run away screaming!

  • Add me to the list of folks who pretty much only open kettle can for high-acid foods. I’ve never had anything turn bad. I pressure can low-acid veggies, but for jams/jellies/preserves and tomato products, the open kettle method seems perfectly fine. My grandmother says she can count on one hand the number of things she’s had go bad in her 65 years of canning. Contrast that to my mother-in-law who is super-paranoid and waterbaths everything and lost two entire batches to poor seals (one of chutney, one of jelly) last year alone.

    I love this blog, but this particular post makes me roll my eyes a bit.

  • My grandmother and mother made grape jelly with the wax. My brother and I loved it and I didn’t realize it was not safe.

    My mother and grandmother have been cleaning out my grandmother’s attic. they found boxes of jars used for canning. My mother wanted to throw them in the recycling bin because most of them were mayonnaise jars that my grandmother re-used to can. My grandmother didn’t want to throw them away because she heard that more people are canning again and she was sure someone could use them. My mom tried to explain that they weren’t safe for canning and my grandmother wouldn’t hear it. Somehow we all survived back in the day, but those jars did get thrown away.

  • Miranda, India and Layla – I’m not trying to dictate how you can. I’m simply attempting to offer the best and most current canning information possible, particularly for first time preservers.

    Amy, I have some of the Tattler lids, but I haven’t used them yet. Planning on it soon, though.

    Kristia, good for you getting rid of those old mayonnaise jars! They’re definitely not advisable for canning.

  • “Somehow we all survived” – the thing is that the people who got killed by unsafe canning techniques are not around to tell their story. So of course, all we ever hear is “well, we were OK”.

    Good luck with your canning Layla. I hope you never end up killing someone you love. I’ll trust the scientists over the grannies any day of the week.

  • I’ve updated some of my mother and grandmother’s methods: I don’t re-use lids or re-use mayo jars for canning. I do still open kettle can pickles. I like to blend common sense and modern advances in technology.

  • I can’t imagine putting all that work into canning something only to end up with a 50% success rated. I’d cry!

  • Also, in my quest to read every canning book my library has to offer, I did noticed several “modern” (last 10 years or so) still including the oven method. I am intrigued but a little scared.

  • Why are Americans so paranoid about food safety? All my friends use the open kettle method, it is standard for homemade jams in Europe, you can find it in every cookbook and I never heard about any problems with it. If people are too stupid to prepare food the correct way, they might as well kill themselves by preparing fish.

    In a country that allows everybody to carry a weapon and still offers XL fast food menus, I’d say canning is your tiniest health problem πŸ˜‰

      1. Not the most tactful comment but pretty much true on the point of us being so food paranoid. And the gun comment is so true it hurts.

  • The other day I saw a reference somewhere to microwave canning. I had never heard of it. What do you know about it?

  • To “Linda,” No. 27 —

    I’ll say this for the OP — she only said that avoiding the open-kettle method was the safest way. She didn’t go on to say that the people who still did do that anyway were “stupid” or “paranoid”, or cast dispersion on European’s health.

    If you’ve been lucky enough to successfully use the open-kettle method for this long, bully for you. I don’t see why you felt the need to then go on and accuse “Americans” of being “Paranoid” or “stupid” — that was very unkind and a little unfair; and, I have to be honest, it sounds a little defensive, as well.

  • Thanks for this easy breakdown of the flaws in these older techniques. I’ll be teaching some canning classes in the upcoming months for our University Married Student Garden and was looking for some solid facts to refute the inevitable questions and comments (mostly about open-kettle canning).

    I still see the first two methods taught in classes occasionally held by my church’s women’s society. I think people can get a little lazy and use the quickest method, but I like a sure bet.

    By the way, are these methods also no longer safe due to changes in fruit/vegetables and acidity? It might make sense.


  • Ana, essentially they were never particularly good ways to can. In the past, home canners experienced more seal failures and spoiled jars than we do today. It doesn’t actually have anything to do with changes in produce over the years. The reason for the changes in best practices is that we know more about canning than we once did. There’s been a ton of research that’s led to these recommendations.

  • Question:
    I’ve only ever made my blueberry jam with the open kettle method, but I pour the hot jam into hot jars just taken out of boiling water and seal them with just-boiled lids, too. They all ping and seal, and I’ve never had mold. So the question is, if there is no mold are they definitely safe?

  • Mikaela, as long as there’s no mold, they should be safe. However, there’s always a chance that a jar could go bad.

  • This post was very informative, thanks! My grandma did the open kettle method, but since I don’t have her around to teach me (sniff), and because I’m paranoid anyway, I’m going to stick to the USDA suggestions.

    Europeans, it’s not about you. Chill.

  • Simple Bites advised using the open kettle method in their canning 101 series last month. I commented that it was not recommended anymore and was surprised to find them writing about it. Your blog reminds me that I am not silly for sticking to updated guidelines for canning. Thanks! This is the simple bites link about using open kettle canning:

  • Yikes Robin. I’m quite surprised that Simple Bites recommended the open kettle method. You are not silly, it is always best to go with the most recent and safe methods.

  • I’ve only started reading recently that steam canners are unsafe, and everything I’ve found said they aren’t even sure yet. I was given one and that’s what I use, but now I’m starting to worry. (sigh) I try to be SO careful with my canning to follow all the rules.

  • My two cents worth. As someone who has lived in a number of countries it seems that the accepted/recommended modern methods are a little different around the world. As Marissa says, the Upside Down method is common in Europe. In Australia, the open kettle method is the accepted modern method for the high sugar/high acid/high salt preserves like jams and chutneys but post-bottling boiling is required for other preserves. And the USA/USDA have taken a more conservative approach than many countries and their modern method is that all preserves need boiling after bottling. I guess what I’m trying to say is that not all these methods are old fashioned, they are just not what is recommended in the USA.

    Also with the open kettle method you shouldn’t get moulds. If you do it means something has happened to contaminate your preserves. e.g. a non sterilised spoon was used to transfer the preserves into the jars, jars were allowed to cool too much before the preserve was poured in, jars not sealed quickly enough etc. This ocassionally happens to all of us and we can just throw the offending jars away (no more risk here than if your milk goes off in the fridge and you take a drink of it before realising). My understanding was that post bottling boiling was actually about the more insidious invisible problems like botulism and that this is a problem in lower acid preserves and hence these really do need to be boiled after bottling for the recommended times. No ifs, no buts, no cultural differences.

    Having said all that. I love you blog Marissa. I find it very inspiring. I just translate some of it into my own country’s modern best practices πŸ™‚

  • Thanks for posting this. People who rely on Grandma’s methods (another one is using those old baling wire canning jars) are just courting disaster.

    I do use the open canning method for jam but only if I have made just enough to refrigerate it afterwards – 3-4 jars max. I figure between the faux seal and refrigeration the jam will keep as long as it lasts in our refrigerator.

  • A few weeks ago I was talking with someone who teaches canning in northern Europe. She said that they consider the US ways old fashioned. That boiling water canning was what they did 20 years ago. I don’t think anyone has used a pressure canner there though, but they tend to eat more seasonally anyways so putting up tomatoes and such isn’t a concern.
    It’s almost impossible to find jars with two part metal lids anymore there. It’s all the bail and rubber gasket.
    Looking at it from the USDA standpoint… I’m following their suggestions but overall USDA is overkill on most things. Plus since USDA started inspecting things food borne illness has gone up… latest being the eggs…

  • Another down side to the sealing with paraffin wax is if you ever develop a mice problem (our neighbor had a brush pile she never cleaned up, just always added to, and we got a few mice in our house because of it) the mice happily eat right through the wax to get the the yummy jelly below.

  • My grandmother and my mother used a stove-top canning pot still widely used in Europe today together with the special glass jars from “Weck”, a german brand.
    These are all glass and you put a rubber isolating band between the jar and the glass lid. To go in the pot, you have to put metal clips on.Afterwards you have to take them off.
    It is a large pot with a rack where you put the filled jars and immerse them in water the same temperature as your canned goods. The water has to be level with the top of your jars. Then you put a special thermometer in as well and start heating.
    Most items get sterilized for more than 1 hour at 100 degrees Celcius.
    This method is really secure and gets good reviews as the most secure way to can from several european food labs, because of the special jars.
    If your preserve goes moldy or even badder ( botulism), the lid will open automatically, because the gases produced by these bacteria will change the internal pressure and thus open the lid. If you use jars with a mechanical closure system or twist off glasses, you will not be able to tell if the preserve has gone bad, therefore you should always use these jars.
    Pressure canners are not used in most european countries( although some people use their steam cooker to can) mostly because of the complete loss of vitamins occurring with this method. The temperatures of 100 Celcius reached in the regular canning pot are already killing most vitamins, but heating them even above most certainly kills even the small rest of nutritients left.

  • To everyone who thinks, ‘oh, it’s safe enough…’ Think again. I had never heard of anyone suffering from food borne illness from open kettle canning. That is, until my neighbor came down with botulism poisoning from his wife’s pumpkin butter which she had been making every year for 25 years. He ate a small amount on toast at 8am. By noon that day he was blind and couldn’t move his arms. By 3pm he was paralyzed and in a coma. He didn’t recover for nearly six months and almost died.

    It’s just better to go overboard and be safe.

    1. Pumpkin butter is dangerous for the home canner. Plus there are more people now with poor immune systems (due to chemo etc) than in the old days. Better to be safe than sorry.

  • I know this is an old post, but just have to add my 5 cents.

    I’m your old grandma that used to make jams/preserves back in the 50s/60s and just pour paraffin on top. I never had a jar go bad and I think if you are careful to sterilize properly and use correct ratios of fruit to sugar, high acid fruit jams/preserves are *probably* safe.

    HOWEVER, I stopped doing it that way years ago–why take chances? Plus, while it takes a little longer to BWB, I think it’s much easier than all the precautions we used to have to take.

    Also, @Cheryl, I think you’re trying to compare apples to oranges. I doubt anyone is saying it’s safe to open kettle pumpkin butter; it’s not even safe to pressure can it.

    1. Hi Maxie et al,

      My Mom used to do jam/jelly with wax. That’s what you did back then. There is enough acid/sugar in jam/jelly that normally there is not a botulism issues and if they go bad you get mold. She very rarely had a bad seal (and you just scraped off the mold if you found it.)

      Our canning methods have improved as we learn more about food safety. I’ve heard some charming stories about canning green beans for hours in a horse trough covered with a blanket over a fire. Makes good reading for Little House on the Prairie. Not happening in my kitchen.

  • I have used the open canning for everything and Have had no trouble, but some times the lids can be bad, meaning not enough rubber on them my mother years back wrote to the Ball co, and got a responds and free lids. You have to check very possiable reason before you foo foo what are Grandmother’s did and like myself I do not have the money to afford all the new equipment that they want you to use I am unemployed and my Husband is also , so we have a big garden and do it very year for at least 30 years . We also hunt off are land to get by. When this happens to you, you have to live off the land like our parents did in the depression…. A lot of the kids today just don’t know .

    1. Just because you’ve been doing it for years doesn’t necessarily make it a recommended technique. Keeping up with the most up-to-date developments in canning ensures that you will make a consistently safe product.

  • Thank you for the article! I can star fruit chutney from my tree. I guess I should have read a book first, I just read the instructions on the box. Since it’s a high-acid fruit, I suppose I don’t have to worry much. The fruit is boiling when it comes out of the deep water bath, though the jars aren’t covered. Now I’m concerned a bit, more research, great place to start, thanks again!

  • What an interesting post…I have a dilemma in my case…

    I’m starting a canning business in Thailand, and my competitors use open kettle AND are FDA Thailand approved…I suspect German and European pickles companies also do the same.

    I have no problem with water bath canning but it makes the Thai cucumbers shrivel, there is no way around it…even with 30 minutes 180-185 method. Even with making toothpick holes in them, soaking in cold water, soaking in brine, soaking in brine/vinegar, fresh cucs, nothing works, they all shrivel. But open kettle works.

    I have pH meters and follow vinegar to water quantities according to USA FDA.

    Any links to European or Australian canning guidelines?

    I’m convinced that open Kettle is fine for high acid foods and that the USA is paranoid, but I would like some scientific evidence. The pH of my brine is 3.5 and after sitting in jars for 7 days pH is still wayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy under 4.6, so what is the danger really? Listeria?

    1. The canning recommendations details on this site are designed for home canning. There’s a whole different set of guidelines for commercial producers. Even here in the US, large scale producers use steam canning and open kettle canning, because they can more accurately control their environment and prevent the transfer of bacteria. The boiling water bath process is there to kill bacteria and other agents that could spoil the finished product. As long as your produce, canning environment, and equipment are meticulously clean, there’s really no reason why you can’t use the open kettle method.

      I don’t have any information about the canning standards in other countries.

      1. In Australia the best thing to do is refer to the USA Guidelines. People here still use cellophane covers, and most haven’t heard of water bathing jams and pickles after bottling.

        I sell a lot of products, so water bathing makes sense as far as I’m concerned. I still get asked “why I bother” the answer is always because none of my products have ever gone off!!!!

        I’ve just invested in a pressure canner as well.

  • I’ve had this argument with a relative recently, she kept insisting that boiling my lids would make the jam go moldy, I tried to explain that I was a bout to water bath the jars, which would kill any mold spores, and I was told that I didn’t need to, she has never done it this way..etc

    Wouldn’t even believe me when I explained that the health Inspector had told me that this was correct.

  • For nostalgia’s sake you could do batch of jam and then seal 1 jar with wax so your dad could have the joy of prying the wax apart. Sometimes I have stuff stuck in my head as being “the best” because of the memories. In reality the jam in jars tastes the same as those sealed with wax, but I am sure in your dad’s mind taking off that wax seal was some sort of passage to a delicious batch of jam. πŸ™‚

  • 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 πŸ™

    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.

      1. 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.

        1. ‘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!

          1. 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.

            1. 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.

                1. My mom did canning for years and did not use the water bath or anything like that. Her canning method was filling the hot sterilized jars with the produce, putting the lids on and turning the jars upside down to seal. No problem whatsoever for all the years she was doing this. So I don’t see where this is not safe at all. Just a comment!

                2. That technique doesn’t kill off any present bacteria and doesn’t create as strong a seal. Additionally, chances are that your mom was making very high sugar preserves. In the current era of canning, sugar content is much lower. That’s great health-wise, but you don’t have as much sugar in a product acting as a preservative and so the boiling water bath step really does provide increased shelf life and safety.

              1. Fruit can only be 100% safely preserved if you are using a pressure canner, not just a hot water bath. A hot water bath only heats foods to 212 degrees (the boiling point of water) – no matter how hot you have your stove setting, boiling water will never rise above 212F unless it is put under pressure. This is the function of a pressure canner. Since fruit is low in acidity, you must heat it to a higher temperature to kill all strains of bacteria. If you hear stories of “My mother did it that way and no one ever got sick”, it is just luck. Just because it hasn’t happened to you doesn’t mean it hasn’t and won’t happen. Invest in a quality pressure canner – then all kinds of possibilities open up for delicious, safe food! Happy canning πŸ™‚

                1. Emily, fruit is high in acid, not low. It’s only vegetables that require a pressure canner. Additionally, bacteria is killed at the boiling point. It’s only the botulism spores that don’t die at 212F.

                2. Marisa is right. Low acid veggies require a pressure canner. Botulism spores die at about 250 degrees F. Foods with high acidity and/or sugar content do fine in a water bath for recommended processsing time.

    2. 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.

    3. I had the same problem with mushy pickles. So instead of throwing them out, each time I opened a jar I drained them and threw them into my food processor. The result was I never ran out of relish. Hey “waste not want not” is a great old creed to live by.

    4. Personally, I do not recommend canning pickles. Fermenting them is so much easier and they taste so much better. Have you ever tasted the difference between a canned pickle and a deli pickle? Deli pickles are fermented, not canned. Basically, you get your pickling cucumbers, wash them not too good (because they need the lactobacillus on the skin to ferment), pop them in a jar, pour a 2% brine solution over them, then cap. Leave them sit at room temperature for 2 or 3 to 10 days (2 or 3 days for milder pickles, 10 days for really sour) (in a bowl because when they ferment liquid will run out), then store them in a cool place (traditionally, the root cellar, but a fridge is better). If you used the right brine concentration, they will never ever go bad, but after a year or so the consistency is not as pleasing. There are a ton of you tube videos on fermenting pickles.

      1. I agree. Fermenting vegetables and keeping them in cold storage is a great option, and is wonderful for things like cabbage for borscht, etc. Fermented vegetables will keep for many months that way.

  • 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.

    1. You would put your stove out on a screened porch that was already set up with a stove pipe. Usually on the north side of the house. I learned how to do water bath canning on a Coleman white gas stove. Just had to make sure I was “fueled and pumped up” before starting!

  • 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.

      1. 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.

      2. Whole milk is not recommended by USDA, guns are not recommended by BATFE, and collecting rainwater is not recommended by DOI…..I grew up eating jams and jellies sealed with wax, drank whole milk, shot pistols, rifles and shotguns, and we gathered all of our washing water from off of the roof of the house. I was never sickened by the Jams, jellies, and the milk. I was never shot and our clothes and ourselves were as clean and fresh as any using “city” water BTW all of our drinking water came from a well and was not treated….I am 74 years old …..Ergo, I challenge you and the USDA to support your warning

        1. Dave, I did all those things too (I think you mean raw milk). I grew up with my grandmother who sealed jellies with paraffin, I milked the cows myself for our milk, and rainwater filled our cistern. People didn’t drop dead right and left for any of that, but some people did die because of that. Today’s methods are safer, and that is a good thing. Some of the things about the good old days are not as good as we remember.

        2. Im 63 and my experience has been the same. I learned from my mother and Grandmother who raised 10 children. All 10 kids lived and their deaths had nothing to do with canning related issues. They all drank raw milk growing up, food preserved by my Grandmother, ate meat raised on the farm and drank water from a well. I feel very fortunate to have benefited from both my Mothers and Grandmother food preservation experience. I do it their way.

    1. Wax did works for a long time, and it still works. It just isn’t as safe as the more modern methods. If any of you are preppers, it would be good to stockpile paraffin.

    2. Wax seals can be unreliable. Some people can get a good seal with them, some can’t–depends on how good you are at it. if the seal is poor, mold will develop on the underside of the wax, which although not super poisonous, does usually contain mycotoxins, which are likely carcinogenic. Color and flavor can also suffer with a poor seal. So if you have good luck with it, you’re getting it done properly. Many others do not know how.

  • 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.

    1. 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.

      1. You can always gently shake the jar as they are cooling after the water bath. That can help redistribute the bits of rind.

    2. 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.

    3. 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.

    4. I agree with you that home canning can be very safe and results in wonderful products. But, even with a very clean kitchen and sterile jars, bacteria are everywhere. When you wipe the rim of the jar before you seal it, it is not necessarily probable, but possible to contaminate it. So a boiling water bath is a good insurance policy for high acid foods. A boiling water bath won’t do much for low acid foods, unless you’re boiling them for hours and hours, which will ruin your produce. Botulism spores don’t die until you hit about 250 degrees F, so you really need a pressure canner for veggies to be safe. It gets up to about 240-250 degrees.

  • 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!! πŸ˜€

    1. 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!

    2. 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.

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

    1. 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.

      1. 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!

  • 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.

  • 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

  • Reading all the comments, I can see why people don’t know who to believe. I agree wholeheartedly with the earlier comments about generating fear and I think it is wrong to tell someone that what their Mothers and Grandmothers taught them is wrong. I myself am in my mid forties, have eaten my grandmothers, my mothers and my own open kettle canned products all my life and so has my family. No one has ever been sick. Someone else said this was just luck. That’s one heck of a winning streak I’d say. I will keep canning as generations before did and skip buying a $200 pressure canner because someone else says to.

    1. Iris, there’s a difference between doing an open kettle canning process on high acid, high sugar and processing low acid foods in a water bath. The first is more prone to spoilage, but nothing bad will happen to you if your jams get moldy. The low acid foods processed in a water bath are actively dangerous because they could potentially harbor botulism. Additionally, a good pressure canner costs all of about $70 these days.

    2. I was taught to open kettle can fruit jams and jellies by my mother who learned from her
      mother. My mother was born in 1916 and her mother in the late 1800’s. They made delicious jams and jellies all their lives. My aunts, sisters, and cousins and I all can this way. We have never had an issue. As an attorney I realize that we have gone overboard to negate risk to such an extent that we have lost the finer arts and culture from past generations. The FDA and Extension websites include statements that their recommendations are because they are trying to eliminate all potential for a jam going moldy based upon some studies on rats that the mold may be harmful. Instead of scaring the next generation wouldn’t it be better to encourage common sense – that if it didn’t seal or has mold throw it out? Needless to say, I will be continuing to make jam the old fashion way and teaching our family’s next generation this lost art.

      1. Trish, just know that the jams and preserves made in your mother’s and grandmother’s time often had far more sugar in them than today’s recipes. Sugar is a powerful preservative and so those items often had a greater chance of staving off the effects of mold. When you lower the sugar, you increase the chances of mold. The boiling water bath kills off those spores and ensures that your preserves will keep longer and better. So there is a reason for it.

  • I used wax to weal my jelly yesterday. It is seeping out on To the wax. Can heat seal it in a water bath with the wax on it? Also it is cold now. Can I still heat seal it in a water bath?

    1. Wax sealing is no longer a recommended method of sealing. At this point, the only thing you could do would be to pull the wax seals off, empty the jelly back into the pot, reheat it, fill jars, apply lids and rings, and process in a boiling water bath canner. However, this action could potentially ruin the set of the jelly. Beyond that, the only other thing you could do would be to freeze the jelly.

  • My mother-in-law in France makes all kinds of fruit jams that she stores in their basement, not in the fridge. The only sealing process is that when the jars have been filled with the hot jam, she covers the jars with strong plastic wrap secured by an elastic (no lid, no nothing). She stores them for months outside the fridge and my partner’s family has been eating them their whole lives (and before, since that was how my partner’s grandmother also made her jams). As a North American I was skeptical at first (like I was skeptical of raw milk cheese at first, LOL!), but now I’ve been eating them all the time too. My mother-in-law says that as long as you put minimum 50% sugar and 50% fruit, there is too much sugar for anything serious to grow. True? It seems to be – nobody in her family’s ever gotten sick from it!

    1. If she is using a ratio of one part fruit to one part sugar, what she’s doing is safe. Sugar is an incredibly powerful preservative and so is preventing spoilage from occurring. However, as soon as you drop the amount of sugar in your jam, the risk of spoilage goes way, way up.

  • Lots of comments here about not having had issues with the old methods. I get it, but I haven’t had any issues with the new methods either. I’d rather be safe than sorry. I can remember my mother sealing jams and jellies with wax; however, we did occasionally find mold. Must we insult each other claiming that a person is lazy or filthy to have a method go bad? I think not. Thanks for current information.

  • Thanks for this article. Very helpful.
    Technically, I think the section on steam canning is not accurate. Steam penetrates better than liquid water, and transfers heat more quickly. BUT, vapors that you can see are NOT steam, which is why Marissa said that steam can be colder than 212. No, it can’t be. And it can only be hotter than 212 if you have a pressure seal (pressure cooker). In any case, your boiling water and your steam will be at the same temp.
    I think that if you leave your cans in a steamer you will get them just as hot, and more quickly, than you would in a water bath. Because you will get steam long before you would have a pot full of water at a boil. That’s how the physics should work out. Just don’t start timing based on visible water vapors, make sure your jars are not touching the sides of the steamer, and start timing based on a thermometer in the steamer, but above the boiling water.

  • Thank you for this article. I can’t believe all these comments from canners who believe they can safely continue to can the way their mothers and grandmothers always have because “they never had a problem”. I’m guessing one such person was responsible for the recent church potluck poisoning.

  • Marissa,

    I know this is an older post, but I have a question in preserves. My grandmother always used a water bath to process, and so do I; but she always cooled chunky jams, marmalades, and preserves upside down. When I asked why, she told me it keeps the chunky bits from collecting in the top or bottom of the jar. True to her word. I have found a more even distribution of fruit using this method. Since everything is water bath processed anyway, does the cause a problem with seals or good safety?

    1. If you’ve done the boiling water bath canning process, there’s no harm in cooling your jams upside down. The only danger is that occasionally the jam sets so that you have an air pocket at the bottom of the jar, which doesn’t look great (and I don’t like having my product pushed up against the lid).

  • Marisa, I hope you get this. I have a question about making birch syrup. What is the best way to preserve the birch syrup. I’ve condensed the birch sap and have it frozen while I am trying to find the best way to bottle it and preserve it. I’ve never canned anything before so I am a real novice. I will have a very small volume of birch syrup, perhaps 6-8 ounces. It takes roughly 128 ounces of birch sap to get 1 ounce of syrup.

    1. Unfortunately, I don’t have any experience canning birch syrup. I’d suggest you look into how it’s done with maple syrup.

  • Hi, there . I use a water bath canning method myself but my mother-in-law uses an open kettle method for making a fig jam every summer. My kids stay over at hers so now I’m really concerned about botulism and any other food borne danger. The jam is very quickly consumed but is that safe? If refrigerated closed right after made is it still a risk? Thank you so much for the valuable info

    1. Canning methods can’t prevent botulism, only acid content can. Figs often fall into the acidity grey zone, so I’d be more concerned about whether your MIL is adding acid to her fig jam than with the method of preservation she’s using (not that I endorse open kettle canning, but with high acid foods, the worst that can happen is that the jam will turn moldy). If it’s consumed quickly or refrigerated, there shouldn’t be any major issue, but if there is visible mold, I suggest throwing the contents of the jar away rather than scraping the mold off.

  • I was just trying to find out the best way to seal jars. I have to heat the condensed sap to a temperature of 190-200 degrees until the syrup is done and then pour it into jars and seal it. I was originally planning to seal the jars with paraffin wax until I read this article. I’m expecting to recover about 8 -10 ounces but I thought I would divide it between 2 jars. I would seal 1 jar and keep the other to use. Sealing the jars with paraffin still sounds like the quickest way to do it.

  • Sorry, no need for an answer after reading all. But I would like to say I didn’t see an answer to Louise’s question about after bath thinning solving. Thank you

    1. The only suggestion I have for that is gently shaking the jars as they cool after the water bath. That can help redistribute the bits of peel.

  • My mother used to make plum butter in a large pot, cover it with waxed paper, and keep it in the garage. When she wanted some she would take off the waxed paper, scrape off the mold, scoop some out, and recover the pot with fresh waxed paper. I’m aware this is anecdotal, but it worked for our family. This was in the 1950’s. I don’t preserve jam this way πŸ˜‰