The Importance of Safe Canning

We've all seen the "Family Favorite" canning recipe featured on a website, blog, YouTube channel, or social media page, but is that recipe safe?  I want to share with you the reasons to follow safe-tested canning recipes, as well as some of the dangers of not following safe-tested recipes.  There are some home canners who say, "My kitchen, my rules", and I will be honest, I will not eat food that was canned in their kitchen!  Not following safe canning guidelines is a recipe for disaster, or worse, death!  At the end of this blog, I will share links to a video of a woman who assumed her canning method was safe, as well as to a video that shows the science behind safe canning and the prevention of botulism, the deadliest toxin known to man.

Is this food safe to can?

Whether it is a recipe found online, one of Grandma's favorites, or if you are just curious if the leftovers soup from last night can be canned, there are some foods that should never be canned.

Those foods are:

• Dairy items - no safe home preservation way to process dairy items to guarantee safe consumption when opened
• Pasta items or starchy sauces - starchy foods can interfere with the heat transfer within the jar, making it unsafe to eat
• Eggs - store bought canned eggs are manufactured with commercial equipment, home canning equipment is not suitable for this 
• Dense foods like purees or mashed potatoes - these food should not be canned, the density of the product prevents even heating 
• Tender foods like broccoli, squash and eggplant - these foods would not be an edible consistency after processing
• Foods with thickened gravies - these foods will not be heated through effectively for safe canning, gravy can easily be easily thickened during the reheating process. 

Any recipe that features any of these food items, is not safe to can.  

If your recipe contains safe ingredients except for one or two of the items listed above, consider adding that ingredient when the jar is opened for reheating.  Noodles, creams, and thickeners for gravy can easily be omitted from a canning recipe, and added once the jar is opened. 

There are rules for "create your own" canning recipes.  Check with a reputable site to make sure that all of the ingredients are safe to can individually.  If all of the ingredients are safe to can, but there is not an exact recipe that gives canning times for your recipe, then process for the food item that takes the longest of the individual ingredients.

I often hear people say, "I buy canned milk and soup with pasta in the store, so why not can at home?".  The short answer to this is, commercial recipes and canning equipment used for these retail products are specially designed for canning them.  They reach a higher heat, and often times have added ingredients that act as preservatives to the canned food, both things that are not available to us as home canners.

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Is this a safe recipe?

Even if the food in the recipe is considered safe, it is important to recognize if the recipe itself is not safe.

Some foods are not recommended to be raw packed, so a recipe that calls for that ingredient to be raw packed might not be safe.  It is important to research why certain ingredients require blanching or thorough cooking before using them in a raw pack recipe.

For some food items such as potatoes, blanching can help reduce the extra starch in the potato itself, and can help maintain the quality by stopping an enzyme found in most root vegetables that can compromise the overall quality.  Blanching potatoes offers a better quality product and is a must if the recipe calls for mostly potatoes.  I do use a recipe or two that calls for a raw pack of potatoes, however, there is such a small amount of potatoes in the jar and the canning time is much longer than if it were just potatoes, that the quality and safety is not compromised.

Recipes that call for any root vegetable to be canned without peeling first is a big NO!  Botulism is more prevalent in vegetables, especially those grown in or close to the ground.  Contaminants can hide in the grooves of the skins of these vegetables, no amount of scrubbing will make them safe, therefore, they must be peeled, and most of the time they must also be blanched. 

Ground beef, although it is perfectly safe to can ground beef once it is browned, it must never be canned from the raw state.  I have seen recipes for "Canned Meatloaf" that use a raw ground beef mixture, these are not safe.  Any recipe that calls for packing the jar with a mixture using raw ground beef or sausage is not safe.  When raw ground beef is canned, it is so dense within the jar, that the temperature at the core may not reach the required temperature to be considered safe.

Is this a safe canning method?

There are a wide variety of different canning methods floating around on the internet and in rebel canning books.  Basically, there are 2 approved methods, pressure canning and water bath canning (boiling water method).  Recently, however, steam canning has made an impression and has been proven safe for recipes that would normally be water bathed.

There is one unapproved method that I have seen become extremely popular, and that is "oven canning".  This is a very old method of canning, yet it is extremely dangerous.  Basically, the recipe tells you what temperature to "bake" your canned goods at and for how long.  Any recipe that calls for "oven canning" is not safe!  Let me tell you why.

High acid foods need to be processed to 212'F for safety.  Low acid foods need to be pressure canned to 240'F (minimum) for safety.  Regardless of what temperature you set your oven to, or how long you leave the food in the oven, the foods inside the jar will NEVER reach the temperature needed to be safely preserved!  This method will only warm the contents and cause the jars to seal, which does not always mean the food inside is safe for storage.  This method will yield a temporary seal on the jar, while the food inside the jar slowly begins to rot.  I know several people who can this way and say they have never had an issue.  As far as I am concerned, and science agrees, they are playing roulette with their health, and the health of anyone they gift their canned goods to.

Think about when you make a meatloaf, or roast a turkey.  The outside of the food heats quicker than the inside.  You may cook your meatloaf for the required time based on the size of the loaf, and the internal temperature will typically only be 165-180.  Imagine canning food in a jar inside the oven, the core temperature may never reach the required "safe temperature" needed.

Also, canning jars are not designed for the dry heat of an oven.  Using jars in the oven can weaken the jars, and can cause cracks to form.  If these jars are later used for pressure canning, they have a possibility of exploding in the canner.

Should this food be pressure canned or water bath canned?

Whether or not a food should be pressure canned or water bath canned depends on the pH value of the food contained in the jar.

Foods with high acid or a lower pH can be safely preserved using the water bath canning method. The Botulinum toxin cannot grow and thrive in a high acid environment.

Foods with a lower acid or a higher pH need to be pressure canned to ensure a safely preserved product.  The low acid foods MUST be heated to at least 240'F to kill any botulinum toxin within the jars.

You may be doing a recipe with mostly high acid or lower pH foods, but some of the ingredients added could change the pH of the entire batch to require pressure canning.  That is why it is so important to have a tested recipe to follow.  If the recipe asks for the addition of lemon juice or vinegar, it most likely isn't for the flavor, but for the acidity.  Never leave this addition out of a recipe, or the quality and safety of your final product could be compromised.

The chart below shows different foods and their pH values.  The lower pH foods are safe for water bath canning, while the higher pH foods require pressure canning.

Some rebel canners practice water bath canning even for low acid foods.  Regardless of how long you boil a jar of food, the core temperature will NEVER reach the required 240'F to kill the botulism in the low acid foods.

If you are following a safe-tested recipe, it will tell you the proper processing method required for a safely preserved food product.

Resources:

Here are some resources to use when a recipe is in question of its safety.

National Center for Home Food Preservation: https://nchfp.uga.edu/

Get advice from your local county Extension Office.  To find your local county Extension Office, click here:  https://www.uaex.uada.edu/about-extension/united-states-extension-offices.aspx

The National Institute for Food and Agriculture, USDA approved resources: https://www.nifa.usda.gov/about-nifa/blogs/usdas-complete-guide-home-canning

For information on how water bath canning works, check out: Water Bath Canning 101

For information on how pressure canning works, check out: Pressure Canning 101

Testimonials for Safe Canning: