12+ Canning Mistakes to Avoid

Preserving fruits and vegetables the right way is easy, but requires attention to detail.

Enjoy the homesteading lifestyle and hone your skills in the kitchen by making the most of the summertime fruits and vegetables that are readily available this time of year. This primer in canning will take lots of the guesswork out of the process for first-timers, and help you understand how easy it can be to make your harvest last all year long. 

Three Canning Jars with a Peach and Sprigs of Rosemary

Peach Rosemary Glaze is Perfect on Poultry, Port or Root Vegetables

Try peach rosemary glazed on roasted root vegetables, pork loin or chicken.

Photo by: Debbie Wolfe

Debbie Wolfe

Follow these tips and tricks to avoid common mistakes in canning:

Beware the Foodborne Botulism

It may take you a few rounds to learn all of the tricks of the trade, but the biggest thing to keep in mind with canning is that you need to do everything in your power to kill foodborne botulism spores. Proper prep, use of fresh ingredients, and flawless seals will eliminate the risk for contamination and illness. Take no risks.

Tip: Botulism can’t stand up to an acidic environment, which brings me to the next point:

Know the Difference Between Boiling Canning and Pressure Canning

Different recipes, different processes! 

A boiling canning bath is used when you submerge the jars in boiling water to seal them.

Apricot Jam: Process in Water Bath

Apricot Jam: Process in Water Bath

Place jars in boiling water bath and process for seven minutes. Remove from pot and cool on countertop. As jars cool, a tell-tale *pop* should be audible, signifying a complete seal. If a jar doesn’t *pop*, the jar may not be safe for shelf storage and may be placed in the refrigerator until used.

A pressure canner is a vented small appliance with a pressure gauge that allows you to heat food in jars hotter than the boiling point.

pressure cooker

Pressure Cooker

The sturdy All American 921 21-1/2-Quart Pressure Canner is great for canning large batches from the garden or can be used to pressure-cook meats to a perfect tenderness.

Photo by: All American

All American

You can seal jars with a boiling water bath when the contents are highly acidic (tomatoes [add a tablespoon of vinegar per pint to increase acidity], pickled foods, and heavily-salted foods). A boiling water bath isn’t enough to kill botulism spores, but as I mentioned above, it’s not likely for botulism to thrive in an acidic container. 

Use a pressure canner for lightly-salted, low pH foods like stocks, animal products, or vegetables preserved in plain water. Reason being, products being preserved at a low pH level are more susceptible to harboring botulism spores, and to kill those spores, you need to bring the temperature above boiling inside a pressure canner.

Tip: Know how your local altitude affects the boiling point, length of time to seal, and pressures required for success. Learn how you should adapt your recipe to ensure that the food is properly preserved.

Clean the Jars, Seals and Rims Before Use

Many recipes suggest that you sterilize materials before assembling them, and it’s for good reason. Prepping the jars in boiling water is a must from a sanitation perspective, and many recipes ask that you soap-wash or boil the rims and seals too. Take time with prep, and your end product will be shelf-safe for a long time.

Canning tips that will make the process easier.

Tips for Success When You're Canning for the First Time

Tips and words of advice on how to can fruits and vegetables with success.

Photo by: Emily Fazio

Emily Fazio

Invest in the Right Tools

Here’s a list to consider, because it’ll make your job easier:

  • pressure canner
  • deep canning stockpot (and a canning jar rack to make it easier to lower and lift all jars at the same time)
  • canning tongs (makes it possible to move individual jars safely, so you won't burn yourself)
  • canning funnel 

Don’t Reuse Seals (But Do Reuse Metal Bands)

The lids with seals are only good for one use only. Once you consume all of the goods from the once-sealed jar, toss (or recycle) the lid, as it has already done it’s job.

The twist-on bands are not afflicted by the wax seal, and technically once the jar is sealed, they’re not critical to the success of the seal at all. They can be used over and over, year-to-year. That’s the reason you can easily and inexpensively get new packs of lids with fresh seals, but it costs a bit more to restock the bands. 

Canning tips that will make the process easier.

Tips for Success When You're Canning for the First Time

Tips and words of advice on how to can fruits and vegetables with success.

Photo by: Emily Fazio

Emily Fazio

Tip: Bands getting rusty? It could be a sign of moisture in your storage space. Add a dehumidifier to combat humidity, or remove and wash the bands entirely, because rust can also be caused my moisture retained under the band from the preservation process. Over time, the rust can affect the seal.

Don’t Double Your Recipe

An especially important tip for jams and jellies: make two individual batches instead to guarantee consistency in the final product.

Don’t Use Artificial Sweeteners

We know, it feels really unhealthy to pour eight cups of white sugar into that jelly recipe, but it’s an important addition, and reducing or substituting it can affect the texture and shelf life. 

Forgetting to Check Your Jars for Cracks and Chips

A slight crack in a jar could end in disappointment (and quite a mess) during the canning process, and a chip in the rim will prevent the lid from sealing properly. Diligently inspect your materials prior to canning.

Canning Fails

Canning Fails

Troubleshooting tips to avoid common canning mistakes.

Photo by: Photo by Mick Telkamp

Photo by Mick Telkamp

Forgetting to Heat the Jars Before Filling Them

Aside from the entire avoid botulism aspect, the benefit to sterilizing the jars in boiling water prior to filling them is to heat them up. It prepares them for being filled with food, and then then plunged again into a hot canning environment.

Don’t Overfill the Jars

Recipes will advise you to leave a 1/2” or 1” space in the jar before sealing. That’s critical, to account for expansion of the contents. Don’t try and fill your jar all the way to the top!

Fill the Pint Jars

Fill the Pint Jars

Remove the sterilized pint jars from the canning pot. Make sure there is not residual water in the jars. Fill the pint jars with the hot jam using a ladle and funnel. Leave at least a 1/4 inch head space. Wipe the rims and add the jar lids and rings. If canning, process in a hot water bath for 10 minutes then remove. Let the jars cool and sit at room temperature undisturbed for 24 hours. After they cool, test the seals. If the jars have sealed, you store them in the pantry for up to a year. Alternatively, if you do not wish to can them, let them cool to room temperature and store in the refrigerator for up to 4 weeks. You can freeze them as well.

Photo by: Debbie Wolfe

Debbie Wolfe

Don't Use the Wrong Salt

Opt for kosher salt, or canning salt, which is pure. Table salt can still be used, but contains other additives that may affect your end product.

Tip: Kosher salt is coarse, and shouldn’t be used in pickling recipes that require the water to have a higher salt concentration.

Clean the Rim of the Jar

After filling contents into the jar, you’ll have to make certain that the top rim of the jar is clean and dry. Even with a canning funnel, you’ll want to double check the rim before you place the lid and seal. Particles of food will prevent the jar from properly sealing the contents. 

Canning Fails

Canning Fails

Troubleshooting tips to avoid common canning mistakes.

Photo by: Photo by Mick Telkamp

Photo by Mick Telkamp

Not Giving the Jars Enough Time to Cool and Seal

The jars must cool in open air for several hours while the seals continue to do their thing. Don’t transition hot jars to a cold or drafty spot in an effort to speed up the cooling; instead, place the jars in a sheltered spot on your counter, atop a towel, until they reach room temperature. Resist the temptation to poke and prod the jars and lids during this time, so you don’t interfere with the sealing process. Once cool, now you have permission to press down on the lid firmly, to make sure that the seal is tight and doesn't "pop" when agitated.

Need ideas for foods to can year?

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