Botulism prevention isn't talked about enough in home food preservation. It is a real and deadly form of food poisoning that makes many home canners nervous. And for good reason!
But canned food is not the only danger of getting botulism. The good news is there are food preservation techniques and safety tips you can follow to ensure you and your family are safe. Learn the signs of contaminated food and the best preservation and storage methods in this podcast.
There are other forms of food preservation and cooking techniques that can have botulism risks. I know this is something that often surprises people, but if you're making and storing food at home, these are important things to know and understand so you don't make these mistakes yourself.
I've discussed the science of home food preservation before, as well as the nine different methods of food preservation, what you don't know about the USDA canning safety rules, whether it is safe to can previously frozen food, and canning myths you should be aware of. So be sure to check out those posts for more information.
If you're new to canning I have a podcast episode, Canning 101, with great information to get you started. I also offer a FREE training called The 5 Essential Steps to Safely Canning at Home. So join me there for more info on canning safety and I'll walk you through everything you need to know.
Everything Worth Preserving
With all that being said, I'm so excited to announce that my new book, Everything Worth Preserving: The Complete Guide for Food Preservation at Home is finally available for pre-order!
This book is about discovering the nine at-home food preservation methods to safely store delicious food for year-round eating.
There are step-by-step tutorials, recipes, and easy-to-use charts. Plus everything you need to know to use cold storage (aka the Freezer), steam canning, pressure canning, dehydrating, fermentation, freeze drying, root cellar techniques (even if you don't have a root cellar), infusion, as well as salt and smoke curing of meats.
What I'm so excited about this book is that it's a literal A-Z recipe guide. For example, if you look up raspberries, it will list all of the ways you can safely preserve them. Then, after that, you'll have all of the recipes and all the techniques for all of the safe methods for preserving raspberries.
We're limited to the number of books we can sell, so if you're interested, go learn more at the link and be sure to snag a copy now because I'm also giving away free bonuses to those who pre-order! Grab your copy of Everything Worth Preserving now.
For now, let's get back to the topic of staying safe from botulism.
What Is Botulism
Botulism is a neurotoxin. It's tasteless, odorless, and you cannot see it. Botulism isn't like getting salmonella or E-coli food poisoning where you'll get pretty sick but probably won't die from it unless there are serious complications.
Botulism is a neurotoxin that grows in a non-acidic and anaerobic environment. So, specifically, if something doesn't have a pH of 4.6 or lower, then botulism can grow in that food (4.7 pH or higher).
It also grows in an area that's absent of oxygen. We usually think of a sealed jar as safe, however, this can be a perfect place for botulism to thrive if the food hasn't been canned properly.
Botulism is tasteless, odorless, and you cannot see it. Many people think if their canned food looks, smells, and tastes safe, then it's safe. However, this just isn't the case with botulism.
Where is Botulism?
Botulism spores are all over the place, but they are very prevalent in soil. This is why some of the food precautions listed below are places where people most often contract botulism.
This is also why any canning recipes that include potatoes, carrots, beets, etc. must specify that those vegetables are peeled before canning. If the recipe doesn't specify, or says this is optional, don't take any more canning advice from the person who wrote that recipe.
Honestly, botulism is so easy to avoid once you understand it and you follow safe and updated procedures.
The cases of botulism in America are usually due to those who are following improper canning recipes or methods. There are a few other ways people have contracted botulism that I want to bring awareness to today.
This is not to cause fear, but rather to arm you with the knowledge necessary to have confidence that your family will be safe.
Safe Canning Practices
Safety canning tips have been around for a very long time. One of the problems with this information being shared is we didn't use to have the pleasure of the internet where information is literally at our fingertips.
There were some updates to canning safety back in the 1990s. These updates informed us that it's no longer considered safe to pressure can summer squash.
There are many recipes that get handed down from generation to generation that are actually unsafe canning recipes. Just because someone you know hasn't gotten sick, it's just not worth risking your or your family's health.
Botulism Prevention: Other Ways to Get Botulism
Beyond canning, there are other ways that botulism can happen. Some of these were so shocking to me that I actually had to look further to make sure the information was correct!
Aluminum Wrapped Baked Potatoes
That's right, raise your hand if you bake your potatoes in aluminum foil! Now, this doesn't mean we need to stop this practice, but there are specific ways to bake them.
Specifically, if you wrap your potatoes in aluminum foil, you need to keep them hot at temperatures above 140° F until they are ready to eat. Or refrigerate them immediately with the foil loosened so they can get air.
Garlic Infused Oils
Because botulism is found in the soil, and garlic grows in the soil, garlic-infused oils can be a source of botulism.
You can only store garlic-infused oils safely in the refrigerator for four days, maximum. So no longer are the days of making large quarts of garlic-infused oil, unless, of course, you want to freeze it or acidify the oil which will make it safe for longer.
I don't have recommendations on acidifying oil infusions so I recommend contacting your local extension office for more information on the safety of this method.
Oxygen Absorbers in Jars
If you are storing dry foods in jars and sealing them, they need to be 10% or less moisture content. If they are more than 10% moisture and put them in a sealed jar, they are a botulism risk.
Below you'll find a few examples:
- Popcorn – You can store popcorn in jars, however, it's typically not below that 10% moisture and can be a risk if you're adding an oxygen absorber.
- Freeze-dried foods are always below 10%, so there is no danger in storing them with an oxygen absorber.
- Dehydrated foods are a different story. To know if something is dry enough to be below 10% you'll need to first weigh your food. Then, after you've dehydrated the food weigh them again to know if you've reached that percentage. If you're not sure, it's better to be on the safe side and just not use an oxygen absorber.
Raw Food in Honey
Many of us have heard the adage that you don't give honey to kids younger than a year because of the risk of botulism because botulism is very present in honey.
Honey is generally on the acidic side, but there are many factors that can come into honey such as the pollens, where it's harvested, etc., so this is not a safe assumption.
After my research, I could not find any documented sources one way or the other that preserving food in honey was safe or unsafe. Because of this, it's a rather gray area.
Because of this, I only choose to infuse dried herbs, spices, flowers, and foods in my honey and oils to prevent the risk is botulism.
Curing Ground Meats
When you are curing meat, specifically when you are grinding up meat to cure it. You need to be sure you're using tested recipes that call for curing salt.
If you're not, you're running the risk of botulism.
I share all of this not to bring fear, but to arm you with the proper information to make sure you're following safe preservation practices so you can line your pantry shelves with homegrown and home-preserved foods you and your family can enjoy all year long.
Related Posts You May Enjoy
- Proper Canning Headspace (Is it Important?)
- How to Preserve Zucchini
- What Causes Canning Lids to Buckle? (+ Proper Tightening)
- The Science of Home Food Preservation
- 9 Ways to Preserve Food at Home
- 6 Canning Myths You Must Know
Hey, pioneers. Welcome to episode number 351. Today's topic, we are going to be talking about botulism mistakes and storing food. I know most people associate botulism within properly canned food, and we will be talking about that, but there are other forms of food preservation that can have botulism risks. I know that this is often surprising to people, but it is something that if you are preserving food at home and storing food at home, which I certainly hope you are, then you want to be aware of these so that you can make sure you are not making that mistake, and in other very exciting news, well, it actually, I shouldn't say other, it has very much to do with this topic at hand, but I am so excited to announce that my new book, Everything Worth Preserving, the complete guide for food preservation at home is available for pre-order.
It is discovering the nine home food preservation methods to safely store delicious food for year-round eating. There is step-by-step tutorials, recipes, easy-to-use charts, and everything that you need to learn about cold storage, AKA the freezer, water bath and steam canning, pressure canning, dehydrating, fermentation, freeze-drying, root cellar techniques, even if you don't have a root cellar, infusion, as well as salt and smoking/curing. What I am so excited for about this book is it is a literal A to Z. The front half of the book, we'll go over in-depth all of the equipment needs, safety, how it actually preserves the food with each of the aforementioned ways, and then there is alphabetical for fruit, vegetable, and meats, literally A to Z. You'll go to raspberries, and it will show you all of the ways that raspberries can safely be preserved, and then after that, you'll have all of the recipes, all of the techniques, et cetera, for each of the safe methods by each food.
When you've got 20 pounds of tomatoes coming in, you can have one source to look for that has all the ways, including vegetables, fruit, and meat. I am so excited, and combination recipes, because I know we all love our soups, and stews and different things like that so that we can have meals ready, on the shelf, and to pull from, so I am so thrilled. I know many of you have been waiting for the information. You have been emailing me, "When is the book available to pre-order?" It's available to pre-order now, and I promise you, this is not a sales gimmick, but if you want to get a copy of the book, I highly recommend that you pre-order right now. In order to pre-order, go to melissaknorris.com/preservingbook.
Melissaknorris.com/preservingbook. You'll also see it under my menu tab underneath Shop. If you click on Books, you'll see it listed there, but the reason for that is there is a paper shortage worldwide, especially in the United States, and the reason for that is because since COVID, more and more people are buying things online, and even before that, the rise of Amazon and things being shipped to your home, et cetera, and so a lot of the manufacturers that were making paper have switched and are making cardboard because there's a greater need for that, and so the first 10,000 copies of the book, our printer has said, "Yes, I have enough paper on hand. We can print 10,000 copies," but beyond that, they cannot guarantee anything. In fact, they told us that they can do their first 10,000 copies, but beyond that, it may be an additional six months before they can get enough paper to do another print run.
The reason I say that is because if you want to get a copy of the book and one of the first copies of the book, please pre-order now, because obviously, those who pre-order will be guaranteed those first 10,000 copies. Once we sell past that, then we won't even ... We'll only be accepting orders through that number because we aren't going to sell something that we have no idea if we can fulfill, so go and pre-order, and there are some really fun pre-order bonuses. There is a ... You'll get a free digital copy of the book because we won't be able to ship that paperback copy right away, so buy the end of summer, and hopefully sooner, you will get a digital copy so that you can get access to everything right now, and then your hardback will be on its way to you as soon as we've got those all lined up and printed, but you'll also get, as soon as you pre-order, the harvest tips and preserving chart so you know when fruits and vegetables are at their peak, the fresh volume needed for processed yield, and what method to use in order to safely preserve all of your favorites, and you get a bonus, Favorite Recipes Using Preserved Food eBook.
This has my favorite recipes featuring preserved food, so you'll have recipe for chicken pot pie, easy pumpkin curry soup, country brulee skillet bake. I promise you, if that is the only dessert you make from it, let it be that one. It is so good. You'll get all of those and more as a pre-order thank you and bonus. If you can't tell, I am extremely excited about this book, but let us get to the episode at hand because there's a lot of really good information to be had. First off, for those of you who don't know ...
Now, some of you I know are seasoned home food preservers, and so you are familiar with botulism, but if you're listening to this and you're like, "Yeah, I've heard people talk about botulism. I don't really understand though, really what is botulism," so botulism is a neurotoxin. It's not like getting E. Coli or salmonella type food poisoning, where you're going to be, throw up and you're going to feel pretty sick, but you won't necessarily die from it unless there's probably further complications. Botulism is a neurotoxin that grows in a non-acidic and anaerobic environment. Specifically, if something is not 4.6 on the pH scale or lower, lower the number, more acidic, then botulism can grow in it, so if it's 4.7 or higher, botulism can grow in that.
It is a little bit unique because it also grows in a anaerobic environment, which means without oxygen, so a sealed jar. Normally, we think of sealed jars as being a form of food preservation, and in some instances, it is. However, botulism is unique and that the toxins can multiply in a non-acidic environment without oxygen, which is a canning jar, and that's why most people associate botulism with improperly canned food. Now, botulism is tasteless. You cannot taste it, you cannot see it, and you cannot smell it, so unfortunately, people will be like, "Oh, well, if your food looks funny or smells funny, then just don't eat it and you'll be safe."
That is not the case with botulism. As I said, it is undetectable by taste, smell or sight, so our safeguards is to follow proper canning. I don't want to go too deep into this episode on that because I've done many, many episodes. I also have free trainings all about that and how to make sure that you stay safe, and of course, it is front and center in the book, Everything Worth Preserving, because botulism is honestly easy to avoid once you understand it and you follow safe and updated tested procedures. Really, there are cases of botulism in the U.S..
Most of them are because people don't can properly. They just don't understand or know what they don't know, and most of the time, they're just not following the instructions that come with canners, especially pressure canners, but there are a few other ways that botulism can be at risk, and so we're going to go over those today. The reason that I wanted to say that is because, one, yes, we should have a little bit of fear about botulism so that we make sure that we stay safe, but I don't want you to be afraid of it to the point that you don't preserve food, because if you follow the tested procedures that are in place, then that is how you ensure that you don't get botulism. It's funny, I get a lot of comments online that are quite interesting, especially I have to say on Facebook and YouTube. I go into this in the book, but I want to preface it here too, that the tested sources and the testing that we have to make sure that we stay safe from botulism on canning, the majority of it was actually done during around World War II, because the government put the funding into doing the test because they needed the American people to can and preserve their food because they needed to take the majority of the food that manufacturers were producing in large farmers and ship it overseas to the war efforts, to the soldiers overseas, and so they needed to make sure that the food that was being preserved at home from the Victory gardens was done in a safe manner.
When I hear people say like, "Oh, that's just the government trying to control you, telling you you have to pressure can your food," no, it's not. It's not. The safety and the funding that we have from that was at a time, and honestly, the safety stuff that I teach and share with you, it's been around since then, but people didn't have as easy access to media as we do now, and even to books and whatnot, and so there's a lot of people who have been canning for 20, 30, 40, 50 years. Yes, they've been canning that long, and thank goodness they haven't got sick, but some of the practices they use are not safe, and the safety practices were in place back then. Now, there have been a few updates in the mid-90's. There was some additional testing that some extension offices, universities, et cetera have done, and so that's why we no longer can summer squash pressure canned.
Now, you can pickle and do relishes and pickle summer squash like zucchini, but it is so mushy that density is an issue, even pressure canned that the heat can't get all the way through because it is so mushy. You know cooked zucchini. It's very, very mushy, in order to ensure that temperatures have been reached and that non-acidic food to kill botulism spores, so you no longer see that. It's never been recommended to can cabbage other than sauerkraut because fermentation actually creates an acidic environment, and that's why you can make sauerkraut, and then you can can sauerkraut, though I choose not to because you're destroying all of the properties of the ferment, all of those good things that we get from ferments with the probiotics, et cetera, so I don't can my sauerkraut, but that is the only way that you can safely can cabbage. With improperly canned food, botulism is a risk.
If you want to dive further into that, I have got resources that we'll put in the blog post links that accompany this episode, which you can find at melissaknorris.com/351. Melissaknorris.com/351, because this is episode number 351. Okay. Beyond improperly canned food, which botulism is a risk, there are actually some other ways that you can get botulism, and this one, I had to tell you, when I first saw it, I had to go to a tested source to be like, "Is this really a true thing?," and that is using aluminum wrapped around baked potatoes. Yes, so specifically that says, "If you bake your potatoes wrapped in aluminum foil, you need to keep them hot at temperatures hotter than 140 degrees Fahrenheit until they are served or refrigerate them with the foil loosened so they get air."
Again, botulism flourishes in an anaerobic environment, so if you let some air in there, then it's okay, and of course, we want to refrigerate that just because there's other food spoilage things after it's been cooked. Yes, if you bake your potatoes in aluminum foil, keep them hot till you eat them or pull that foil back and loosen it, and put them in the fridge. That is a thing. I was actually shocked. Now, many of you are probably familiar with this.
I do think I've actually talked about this before on the podcast and in some different things, but when we are making infused oil, this is a biggie because I usually see this every summer around tomato and garlic harvest time, I will see people posting, making garlic infused oil, and they must not know that garlic in oil is a huge botulism risk. Now, botulism spores are kind of all over, but they are very prevalent in soil, so anytime you have a root-grown crop like potatoes, aluminum foiled potatoes, ah, garlic comes from the soil, any of those have a higher likelihood or a higher load potential for botulism, so that is why with canning, that you must peel your vegetables before canning. Carrots need to be peeled. Potatoes, when you pressure can them, need to be peeled. Beets need to be peeled, and if you are ever reading a canning recipe from a blog or anything like that, and it says peeling is optional on root crops before canning, do not use any of their canning recipes because it's not optional when it comes to canning.
Now, I know that a lot of nutrients are in the peel, right? We've heard that. That's like, "Oh, a lot of the good stuff's in there," and when you're doing regular cooking in your house, absolutely, that is the truth. It's not the case with canning, however. Back to the garlic and infusing it in oil, that is a botulism risk, so if you are making homemade infused oil with garlic and herbs, it needs to be stored in the refrigerator for four days so you can actually only safely sort in the refrigerator for four days.
Yes, even in the fridge, four days. After that, because inside the oil, it's an anaerobic environment, and oil is not acidic, and neither is garlic, and so botulism can develop after four days, so refrigerate it regardless, but even in the fridge after four days, it needs to be tossed out, so do only very, very small amounts if you want to be making it that fresh, and I do love garlic infused oil. I think it's delicious, and with herbs, or you can freeze it, or there are ways that you can actually acidify it. There are options that you can acidify the garlic, but it's very, very specific from extension offices. They give extremely specific directions that will make it safe for longer.
Now, up next is, "What about storing your bulk foods with oxygen absorbers?" Remember, botulism, anaerobic, oxygen absorbers take the oxygen out, it's a sealed jar is a sin issue, sometimes, so if you are storing dry goods or dried foods in jars and sealing them, they need to be 10% or less moisture content. If they are more than 10% moisture and you put them in a sealed jar with an oxygen absorber, it can be a botulism risk, and this one surprised me, popcorn. Now, popcorn, you can store in a sealed jar. I do that, but do not add an oxygen absorber, okay, but you can put those in a jar and have your lid down really tight, et cetera.
That's fine, but do not put an oxygen absorber in there because popcorn is not dried to beneath 10%. As you know, if popcorn dries out too much, then it doesn't pop, and then we're all frustrated and irritated, so popcorn is one you do not want to store long-term with an oxygen absorber. Now, with your dehydrated foods at home, freeze-dried foods are always well beneath 10%, because freeze-dried foods have much less moisture percentage than 10%, so storing your freeze-dried foods with an oxygen absorber is fine. Dehydrated however, that is something where you would had need to make sure you would use a scale to make sure that it had been dehydrated past 10%, and the only way to know that is to weigh it beforehand. It's weight before dehydrating.
Then, weigh it afterwards to make sure that that much ... You have to do the math and see that the moisture has been removed. Now, I do dehydrate my fruit, and I'm pretty sure that my dehydrated cherries, they are acidic, however. That is a fruit, right, so there you go, acidic foods, but that being said, my cherries, I don't like them brittle. I like them still slightly chewy, and so I don't ever use an oxygen absorber with my dehydrated fruit when I'm storing it.
They don't need it. When it comes to that, I've heard people say like, "Oh my gosh, freeze-dried eggs, raw eggs. You can't put oxygen absorber in there because you could get botulism." Well, if they weren't freeze-dried to below 10% or if they were not done to at least 10% or lower ... Oh my gosh, I'm saying that backwards.
If they're higher than 10%, that would be true, and that's why I do not choose to dehydrate cooked eggs. You should not dehydrate raw eggs anyways, but even cooked eggs, I don't dehydrate because a dehydrator doesn't get them as dry as the freeze-dryer. That is a thing, knowing the percentage of how much something is dried before putting in any type of oxygen absorber. Now, another way that we should be aware of botulism, and that is raw herbs or raw things in honey. Now, we know, many of us have heard the adage, "You don't give honey to children that are less than a year old because of botulism."
Okay, so we do know that honey can ... I don't know the actual percentages of botulism cases from honey, but it is something that is documented and known. When you are infusing something that could already have a potential with botulism, you want to be very careful, but that being said, honey has been used for a very long time, and so infusing with it ... Honey is usually on the acidic side, but with anything, some of it has to do with harvest, with pollens. There's a lot of different factors that can come into something like honey to know how acidic is it or not, so we can't go just by that usually, it's acidic or not if you are wanting to test on botulism, because the home pH test strips and stuff are not accurate enough to test for botulism, so just taking a pH test strip and dipping it in recipe that you want to can, that is not a safeguard because there can be, after it sits for so many days from being processed, does the heat penetrate through, et cetera, all the way.
Like you can do pickled eggs, but the pickling brine can't get through the egg into the center enough to get it acidic enough to prevent botulism. That's why you don't can pickled eggs. Pickle eggs need to be kept in cold storage. There's more at play than just pH levels where I was trying to go with that in a long, very rambling way as I realize, but can you infuse honey with garlic? Could it be a botulism issue?
I know a lot of people who do it. I have to say that I researched and researched and researched, and I could not find any extension office, actual lab documented source one way or the other that could say, "If you follow these XYZ steps, that it is safe," so that one, I'm kind of leaving it a little bit of a gray area onto whether or not. However, anytime that I am infusing something fresh, I only infuse dried items in honey or oil, because it's not just botulism, but you have the potential for mold, so I only use dried herbs, dried spices, dried flowers, et cetera in my oils and honey and all of those things. I don't do fresh in them. The only time I use fresh herbs and fresh spices and fresh plant matter is if I am doing a tincture, and then I'm using alcohol and/or vinegar, but not with oil and honey.
Okay. Up last, ways to avoid botulism is when you are curing meat. When you are curing meat, specifically ground meat, when you are grinding up meat to cure it, you need to make sure that you are following a tested ratio recipe using curing salt, because if not, you are running the risk of botulism, so I highly recommend if you're getting into charcuterie where you are using ground meat, that you are not just making up some type of recipe or just following something willy-nilly, that you are learning from somebody who really understands the science of it, and that you are using proper procedures when you are using those types of methods, because that is another way that you could potentially have issues if you're not using curing salt with ground meat and those types of things. That hopefully didn't put you into a fear state, but made you aware so that you can make sure that you're not making any of those mistakes and keeping up-to-date on your home food preservation. I hope that you are filling up those shelves if they're in the freezer, the fridge, and then especially the pantry, et cetera, with a bunch of wonderful bounty of home preserved foods, and go and grab your pre-order of the book because it will help you do so even more.
If you are interested in charcuterie and doing some of that old-school, traditional style butchery, you are going to love next week's episode, so until then. Blessings and mason jars for now, my friends.
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