10 Canning mistakes you may be making and don’t even know

Although canning can be a bit intimidating, it is so much fun. It is also quite rewarding when you see your shelves full of brightly colored jars that have food you preserved yourself.

We all know how much hard work actually goes into those jars. All that hard work pays off when you are eating fresh tomato salsa and all other kinds of food all year round.

Lately, very many people have embraced the idea of canning in their homes. For this reason, there are so many articles about canning floating around. 

The last thing you want to do is make a canning mistake that will make you or your loved ones sick. It beats the entire purpose of canning.


I believe we have all had our share of canning disasters. There are so many things that can go wrong during canning.

This includes seal failures and broken jars. Some of these canning disasters threaten to destroy all your hard work and as a result, make you not want to ever try canning again.

Some of the canning mistakes you could be making are;

  1. Using fresh instead of packed lemon juice.
  2. Using a water bath canner for low acid foods.
  3. Not checking for air bubbles
  4. Not measuring the headspace
  5. Reusing lids
  6. Placing hot jars on counters
  7. Overtightening lids
  8. Freezing food contents in just any jar
  9. Not following the recipe
  10. Flipping jars upside down to seal

However, this should not scare you away. You would be relieved to know that even the most seasoned canners make mistakes sometimes.

Canning Food Preservation Ideas For Beginners. Click here to read.

Preserving food using the canning method is in fact very specific. It is not that difficult, but it requires some amount of exactness.

A very small mistake can upset the entire process. Other times you may get discouraged because you can’t fathom what mistake you are making. However, these mistakes can very easily be avoided.

Scientists have conducted extensive studies and as a result, they have come up with recommendations to ensure that whatever you are canning will not contain dangerous bacteria.

Institutions like The National Center for Home Food Preservation take their time to research and make safety recommendations.

As much as it is rare to get cases of poisoning and death from bad canning, it actually happens. You don’t want you or your family to be some of the few victims, do you?

Common Canning Mistakes

Here are a few mistakes you may be making and don’t even know. We learn every day, so I’ll explain why you should not do them and what the correct way for safe canning is.

  1. Using fresh instead of packed lemon juice.

It is very easy for anyone to assume they can swap the store-bought lemon juice with fresh lemon juice that they make at home.

Well, you really shouldn’t. This is simply because bottled lemon juice has a consistent pH/ acid level. This makes it suitable for canning fruits and vegetables that may require additional acid.

On the other hand, fresh lemon juice has an inconsistent pH level which makes it rather unsuitable. It is important to note that lemon juice is not just meant to add flavor to whatever you are canning.

  1. Using a water bath canner for low acid foods.

This tends to be a common mistake for both beginners and people who have been canning for a while.

We are all aware that water bath canning is for high acid foods and pressure canning is for low acid foods. Unfortunately, some people still use the water bath canner for low acid foods. It is a dangerous mistake.

The higher the amount of acid in the food you are canning, the less likely botulism can survive.  Garden produce such as green beans, carrots, and corn should be canned in the pressure canner.

The same goes for soups and meat. Using a water bath canner is not recommended since the temperatures will not be high enough to kill botulism spores.

Also, Click here to read all about Water Bath Canning.

  1. Not checking for air bubbles/using metal utensils to release air bubbles

Checking for air bubbles normally seems like a silly step. But it is a really important step. Air bubbles can actually give space for bacteria to thrive and live.

We definitely don’t want that. So just use those 30 seconds to remove any air bubbles that may be trapped in your jar.

You should never use metal utensils to release air bubbles. Always go for wooden or plastic utensils. Metal utensils tend to etch the glass and this may lead to jar breakage over time.

  1. Not measuring the headspace

Do you see that little space between your jar contents and the lid? Well, that is the headspace.

In canning, you always want a vacuum seal and that headspace is pretty much what will ensure that you get one. It is therefore quite important that you measure the headspace.

For instance, if you overfill the jars, the contents may boil out during processing. Any food residue on the rims can prevent the formation of an airtight seal.

On the other hand, leaving too much headspace may mean that all the air will not vent from the jar during processing. Consequently, a vacuum seal may not be formed.

  1. Reusing lids

The jars and bands can always be reused. However, lids should never be reused. There is no exception to this rule. I know the idea of buying lids every other time can be tiring, but better safe than sorry.

Once you use your lid, the plastisol seal is spent and will not recover enough for reuse when processing.

Simply put, your seal will not be secure and this will eventually lead to food spoilage. We don’t want that, do we?

  1. Placing hot jars on counters

I understand that the canning process can be quite a task and you may be tempted to ignore simple steps like placing a towel on your kitchen counter before you place your hot jars on it.

This step is pretty important. You do not want to change the temperature of your jars too suddenly.

A cold kitchen countertop can actually cause your jar to break. To be safe, always place them on a kitchen towel so that they do not go into thermal shock and break.

For the same reason, you should never put hot jars directly into your fridge. Let them cool down first.

  1. Overtightening lids

There is a specific way you are supposed to screw your lids. Simply use your fingers to screw down the bands evenly and firmly just until a point where resistance is met.

It is normal to be tempted to overtighten lids using the full strength of your hands but don’t give in to this temptation.

Overtightening will prevent air from venting out of the jars which will consequently lead to seal failure or buckled lids.

Once you process, the bands may appear loose. Keep in mind that this is normal and there is no need to retighten the bands. Retightening the bands may actually break the seal that is forming.

  1. Freezing food contents in just any jar

Yes, you can’t just freeze any wide-mouth jar. During freezing, some contents may expand leading to breakage of your jar.

It is actually quite easy to tell which jars are freezer safe. Just look at the neck of your jar i.e. where you normally secure the bands. If the jar has ‘shoulders’ under the neck, then it is not freezer safe.

If it simply tapers from the neck of the jar, then this jar is freezer safe.

  1. Not following the recipe

Unfortunately, canning is an exact science. It is very important that you follow the tested and approved recipe. Developing your own canning recipe is quite risky.

This is because you need to ensure you have the right level of acid, right headspace, processing time, and many others. At the same time, you should not use recipes that are too old.

For the sake of food safety, always use recipes that have been tested and approved. If you are new to canning, consider purchasing a canning book to guide you throughout the process.

  1. Flipping jars upside down to seal

It is rather unfortunate that some people recommend flipping your jars upside down as part of the sealing process.

Even though your lid may seal, there is no guarantee that the seal will be solid and secure.

Additionally, the jars may seal but later on become unsealed. This may lead to food spoilage and you will keep wondering what you did not do right.

Seal your jars using the right process. Do not flip them upside down.


  1. Using paraffin wax to seal the jars

If you come across any recipe telling you to use wax to seal your jars please do not use that recipe.

I understand the logic that the wax is meant to create a secure seal to keep out air and prevent the growth of bacteria but there is no proof. I believe our grandmothers used this method in the past.

You should know that paraffin wax does not in any way destroy bacteria that are already inside the food. There is absolutely no guarantee that your food is safe.

Just stick to the lids and rims. This way you can always be sure that your food is free from bacteria.

How to Preserve Fresh Tomatoes without Freezing. Click here to read.

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