But I am always very concerned by some of the unsafe practices being condoned on the Internet (and even here in our comments section). And by dangerous I mean, that someone could die with these unsafe practices. In fact, someone almost died the other day when a canner in Washington cut corners, canned improperly and got botulism poisoning. That said…
Please Don’t Be Afraid to Can!
I don’t want to scare anyone off from canning – just the opposite! You just need to understand that is NEVER okay to cut corners (especially with low acid foods such as veggies & meat). So in this post, I want to cover the basics of safe canning and explain the science behind these rules.
And for the record, I am not just basing what I say here on my “experience”. Yes, I am a life-long canner, but I have also been through Master Food Preserver training through county extension and attended professional cooking school. All the recommendations here are based on the USDA requirements for safety.
If you are armed with a clear understanding of how the canning process works, you will feel confident and safe in all the preserving you do.
So here we go…
Food Can Be Divided Into Two Categories:
1) High Acid Foods:
These have a pH below 4.6 and are considered the safest and easiest things to can. Jam, jellies, marmalades, pickled products, acidified tomatoes and whole fruits fall into this category. They are considered “safe” because their pH level prevents the scary toxins from forming. In other words, you cannot get botulism from a properly canned high acid food. It simply can’t grow there.
Since the botulism spore cannot grow in the high acid environment, you don’t have to worry about killing it with a super high processing temperature. Instead, you just need to kill molds, yeasts and bacteria that can cause spoilage. And these are easily killed at the lower temperature achieved in a boiling-water canner (aka: water bath canner) – where the food is brought to 212 degrees F, the molds/bacteria are killed and a vacuum seal is created when the jar cools. The pH level of the finished product takes care of the rest. Click here to learn more about water bath canning including altitude adjustments to recipes.
You can make jams, jellies and pickles to your hearts content and as long as you follow the recipe, you can sleep well knowing they are extremely safe. They are perfect for beginners and advanced canners.
2) Low Acid Foods:
These have a pH above 4.6 and require a more advanced canning process. It’s not that they are difficult to process. It’s just that you need specialized equipment – a pressure canner in order to do it. And people are usually more comfortable using this equipment when they have already experienced canning in a water bath. All vegetables, meat, soup, or mixed products (like chili) fall into this category of pH level. (For information on fermented foods, see the end of this post.)
Now here is the important part: The botulism toxin CAN easily develop in a pH level above 4.6 when it is in the sealed environment of a canning jar! You cannot taste or smell botulism when it is present in a jar and it is deadly. So in order to ensure safety, you must kill all spores at a super high temperature (240-250 degrees F) for an extended period of time. You can ONLY reach that temperature with a Pressure Canner.
You MUST process all low acid foods (like plain vegetables, meat and soup) in a pressure canner and follow modern instructions properly or you can get into trouble. If you don’t feel you are ready for this, stick to jams and pickles instead.
People get confused about pressure canners, which is understandable. A pressure canner is NOT the same thing as a pressure cooker (which is used to cook food quickly). A pressure canner is made specifically for canning and comes as either a weighted or dial gauge model (or both). It processes the jars under pressure which allows it to reach a much higher temperature than you can reach normally. Water boils at 212 degrees F, but a pressure canner takes the food to 240 degrees F and above.
If you want to use an old pressure canner that is handed down or that you found at a garage sale, I highly recommend that you have it thoroughly checked out through your cooperative extension office before using it. First, it needs to be new enough that it has a UL approval for safety with the fancy pressure release valve, etc. Second, things like gaskets and safety valves can have issues over time so you need to verify that yours are sound. And third, a vintage pressure gauge must be checked for accuracy.
In fact, you should have the gauge on any pressure canner checked every year at your local county extension office or hardware store. It is easy to do and is important to verify it every year. A gauge that is off will either under-process (dangerous) or over-process your food – making it unappetizing.
So if you are going to try pressure canning, buying a newer (modern) canner is really a better option rather than a very old one used by your grandmother. Yes, it can be “used”, but it needs to be a modern model. Yes they can be expensive. But they are also lighter weight, have fewer issues or problems, are very safe (UL approved) and they will last for a lifetime of canning.
Is Grandma’s Recipe Safe?
When people tell me that they always water bath can their green beans (a low acid food) just like grandma and “Well…no one ever dies!”, I shudder. I also point out that I know people who smoked their whole lives and never got lung cancer. But that doesn’t mean, given what we know today, that we should take up the habit and assume we are perfectly safe. We know so much more now than during our grandparent’s time and therefore, we need to use that knowledge to ensure safety. Don’t take unnecessary risks.
A recipe that belonged to your grandma or great-grandmother may be perfectly safe. But it also may not have a proper processing time or method. So to be sure, just have it checked by a Master Food Preserver at your local county extension office. There are usually minor adjustments needed, such as extending the processing time or adding an acid to make it safe. And then you can still make that heirloom recipe and feel the connection to your heritage safely.
Whenever you preserve food, use modern recipes from a reliable source such as the National Center for Home Food Preservation or a canning author or blogger who specifies that they use modern USDA guidelines. Then you will be free from worry and can concentrate instead on those delicious canned flavors!
Note on Fermented Foods:
I didn’t initially include a mention of fermented foods in this post because they are not always “canned”. (Doing so kills all that good bacteria that you worked so hard to create in the fermentation process.) But people often wonder if they can get botulism from fermented foods like cabbage or meat. The answer is NO. You cannot get botulism from fermented foods.
Botulism needs a low acid and anaerobic environment to grow. The fermentation process creates lactic acid and you have the addition of salt to prevent any bad bacteria from growing. And when fermenting on the counter, it is not sealed in an anaerobic environment. You can feel safe with fermented foods. Also, you can process (or “can”) things like fermented pickles and sauerkraut (when they are finished) in a water bath because when it stops fermenting it is now a high acid food. Just follow a USDA approved recipe for proper processing times. I will write more about fermented foods in a future post.