Canning Safety Rules: 6 Must Follow Guides

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Last Updated on March 21, 2024 by Share My Kitchen

The Summer Season means that the canning season has begun or is ongoing! It’s also time to refresh your knowledge of canning safety rules. Although it might not be the most exciting part of canning or preserving food, it’s certainly the most important.

Canning is science, not art.

Home canning is not the same as cooking, so you cannot just “get creative.” To ensure safe canning for your family, there are certain canning safety rules that you must adhere to. Why can you even bother to can your food at home when it is not safe to eat, right?

It is always surprising to me that there are people who oppose the recommendation that you must always use up-to-date and proper canning methods when doing it at home. Or, there are also those who proudly call themselves “canning rebels” proudly. It is unbelievable, but it’s real.

The protests often sound like, “my grandma did this way for years and never killed anyone, so I’m going to continue doing it this way.” Or, “I’ll take my chance [even though I know the risks involved].”

Why would you want to risk your life or your health? Or, even your family’s life?

Home canning is an easy and safe way to preserve food, and enjoy the fall and summer bounty all year round. However, you should be careful with the following basic and sensible rules.

Don’t be a rebel! This is one aspect of homesteading (and essentially your life) where it’s actually cool to follow the rules.

These are the six rules that you must follow in order to make sure your home-canned food is 100% safe to eat.

Canning Safety Rules to Always Follow

1. Always Use a Canner to Can Food at Home

This one is obvious. However, some people still believe it safe to can food in an oven, using the open kettle method, or the inversion method, where you just put hot food in jars and seal the lid, either right-side-up (open kettle) or upside down (inversion).

You might seal your jars this way, but it doesn’t kill the harmful bacteria. Essentially, you will seal up these bacteria nicely and tight inside your canning jars.

So, when canning food at your home, you must use either a water bath canner or a pressure canner

You don’t actually need a water bath canner if you are water bath canning. Instead, you can use a large stockpot with a rack in the bottom. However, you must either process the jars in a boiling water bath or in a pressure canner, depending on what food you are canning.

2. Low Acid Foods Need to be Canned Using a Pressure Canner

This is the most important when it comes to canning safety rules.

High-acid foods such as fruits, jams, jellies, pickles, pie fillings, etc. can all be water-bath canned. However, all low-acid foods MUST be canned using a pressure canner.

Low-acid foods include meat, vegetables, fish, soups, stocks, combination meals, and so on.

A boiling water bath canner can achieve temperatures high enough to kill off most harmful bacteria you can find in food. However, only a pressure canner can reach temperatures high sufficient to kill off botulism spores. These spores can produce a toxin under the right conditions if they are not killed or rendered inactive with the high heat in a pressure canner.

Although botulism can be found on almost everything, including fruits, vegetables, soil, and water (they are EVERYWHERE), they are virtually inactive in most cases. So, they are completely harmless.

But, these spores can produce a neurotoxin that can cause serious harm to your health if they are given the right environment and conditions. Let’s take a look at what these conditions are.

Botulism particularly thrives in moist, low-acid, anaerobic (low oxygen or no oxygen), room temperature environments. These are the exact conditions in a jar of home-canned food.

It is important to kill botulism spores before they can turn deadly, so you must pressure can low-acid foods. Don’t skip this one!

3. Some Food Do Not Need to be Canned

Some foods should never be canned, even with pressure canners. These foods include:

  • Dairy and Eggs: this includes milk, cheese, butter, etc.; pickled eggs
  • Pumpkin Puree: winter squash or pumpkin puree, acorn, butternut squash, etc. are too thick to allow the pressure canner’s high heat to permeate; pumpkin and squash should be cubed and pressure canned
  • Flour, Pasta, Rice, Cornstarch, Arrowroot Powder, etc.: these will become mushy and clumpy, so this is more of a quality concern than a safety one.
  • Oil: olive oil, avocado oil, coconut oil, etc.; it is fine to have a little oil in a canning recipe that has been tested, but oil-based foods such as pesto or sun-dried tomatoes in oils should never be canned
  • Nut Butters: peanut butter, almond butter, sun butter, etc.

Home canning is not for dairy products. Do not follow any recipe on how to can milk or butter at home. These are not safe!

Yes, dairy can be frozen. Some forms of dairy can even be fermented and dehydrated. However, you should never can it. Dairy is low in acid and high in fat, which can help protect spores against being destroyed by heat. So, there’s no safe method to can dairy products at home.

Jam recipes may call for a tablespoon of butter. This is fine, and it helps to create foam at the top of the jam. However, you cannot can a stick of butter.

Pumpkin puree should also not be canned as it is too thick to allow heat from a pressure cooker to penetrate and kill all of the harmful bacteria presents.

But, you are allowed to can cubed winter squash or squash in a pressure cooker. Then, drain it and purée it when you’re ready to use it. If you prefer to make the purée ahead of time, freezing is the best way to preserve it.

You should not can flour, rice, cornstarch, arrowroot powder, and pasta. This is more of a quality issue than a safety one, but it can make your food almost unusable. So, follow this rule too.

This happens because starch and flour products break down eventually, and they become mushy and gross. For example, you could pressure cook chicken soup. However, don’t add noodles. When you are ready to serve the soup, cook the noodles fresh. You can store dried pasta noodles for a long time, so you don’t need to make any special preparations. Similar to rice.

The same goes for adding flour, cornstarch, and arrowroot powder to recipes as thickeners, these ingredients might work when they are being prepared fresh, but not for canning. This is evident in home-canned pie fillings.

These thickeners can be added to your pie filling when you are baking it fresh, but adding them to your home-canned filling could result in a runny, lumpy mess that you won’t want to eat.

For pie fillings, you can only use Clear Jel as it’s the only approved thickener for canning. It is modified cornstarch, which is non-GMO, so don’t worry. It can withstand high temperatures of canning and preserves your home-canned pie filling thick and tasty for a long period of time.

4. Use Mason Jars for Canning

Although this one may seem obvious, it’s still surprising that a number of people think it’s safe to can food in old jars purchased from the grocery store.

Reusing old lids or jars from the grocery store won’t guarantee a good seal, which can lead to food spoilage.

Because they are all different sizes, they may not fit the Mason jar lids. And, these lids are the only ones approved for home canning.

Mason jars and bands, however, can be reused, and you’ll often find them at garage sales and thrift shops for a fraction of the cost. It’s fine as long as the Mason jars aren’t too old.

Some really old Mason jars won’t fit today’s lids, and they are more susceptible to cracking and breaking due to their age. These vintage jars make great collector’s items, but not for canning.

You can also reuse the jars repeatedly, making them very economical and environmentally friendly. So, even if you need to buy them new, you will get your money back in the end.

5. When Canning, Always Use New Lids

Mason jars and bands can be reused, but not the lids. Canning lids were made so that they can only be sealed once. There’s no guarantee that the lid will seal again once they have been sealed onto a jar.

Even if they seal again, it might not be as strong, and it will break. This could cause food spoilage.

It’s not cost-effective to reuse lids to save a fraction of the price every canning season.

You can, however, reuse these canning lids for plenty of other things. They are great for storing dried goods in your pantry, and for making (and labeling) homemade products, such as body butter and bath salts, candles, etc. Or, you can use them for storing food in the fridge in Mason Jars. For example, extra food from a canning project, homemade mayo, yogurt parfait, or overnight oats.

You can buy Tattler lids if you want lids that can be reused. These lids are a bit more expensive upfront but can be reused repeatedly.

6. Always follow a safe and tested recipe

Many canning safety rules and recipes floating around the internet are unsafe. There are also many outdated and unsafe canning practices and recipes that have been handed down from generation to generation. And, some people will argue that they have used these methods and recipes before and that is enough evidence to support safe canning. But, it does not sound as convincing as the best piece of evidence.

There has been a lot of research on food safety, and what scientifically makes home-canned food safe or unsafe to eat. In our grandparents’ time, much of this research wasn’t done and the information was not available. And, as with all scientific advances in history, our knowledge of bacteria and food safety has advanced.

However, not everyone is able to keep up with the times or believe in the science of food safety. Anyone can also post any recipe on the Internet. So, be cautious and avoid recipes for canning milk, or recipes for water bath canning green beans (non-pickled ones).

To ensure a safe finished product, make sure you follow the most current, tested, and safe canning recipes and practices.

The National Center For Home Food Preservation, the authority on home canning in North America, is a good source. And, anything that Ball/Bernardin has published since Ball is the maker of most Mason jars found in the US, while. Bernardin is a Canadian manufacturer.

For all things, canning, preservation, and cooking at home visit the National Center For Home Food Preservation website.

Getting a solid canning safety rules book with tested recipes is also a good idea. It is recommended to check the Ball/Bernardin Complete Book of Home Preserving.

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