Pressure Canning 101

Tired of wasting fresh produce – or spending all your money at the grocery store?

Enter – pressure canning. This method of preserving food not only extends the shelf life of your favorite meats and vegetables, but also helps lock in nutrients so you can enjoy healthy food even in the dead of winter.

Pressure canning is more than just a cooking method. It’s an art form that has been passed down from generation to generation, used by countless families to ensure that they had enough food during long winters or seasons of scarcity. This method of food preservation has been used by homesteaders, farmers, and gardeners alike to keep produce fresher for longer periods of time.

But you don’t even have to have a garden at all to enjoy the benefits of pressure canning.  You can easily pressure can the food you buy from your local farmer’s market or other vendor to make sure you have all the food you need – whenever you want it. 

However, pressure canning can be intimidating, especially for first-timers. We’re here to help walk you through it. 

What is Pressure Canning?

Pressure canning is a method of preserving food in glass jars by processing them with high temperature and pressure. The process kills any harmful bacteria and seals the jars, keeping the food safe for long-term storage.

But why pressure canning and not just regular canning? 

The main reason is that pressure canning allows for preservation of low-acid foods like meats, vegetables, and some fruits (though these tend to be best suited for a water bath canner). These foods can contain botulism spores which, when consumed, can cause serious illness or death. These spores multiply in the oxygen-free environment of a canned jar of food. 

Regular canning methods – ie, water bath canning – don’t reliably kill these spores and can lead to food poisoning. Pressure canning reaches a higher temperature (240-250°F) than regular water bath canning (212°F), so it kills the spores and ensures the safety of your food.

What Foods Should Be Pressure Canned?

Any low-acid food with a pH level of 4.6 or higher should be pressure canned. This includes things like meats along with most vegetables, like green beans, carrots, and potatoes. 

These foods can’t be safely canned using a water bath canner because the high temperature and pressure of a pressure canner is required to destroy any botulism spores that might be present. 

Foods like tomatoes, fruits, salsas, jams, and relishes are safe for a water bath canner and can also be safely processed in a pressure canner, but the high heat and pressure of a pressure canner may be a bit too much for these foods (so you’re best to stick with water bath canning them to ensure the right flavor and texture in your finished product).

You can even can full meals in your pressure canner – a hidden secret that not many people are aware of. By canning things like soups, broth, and stews, you’ll have a ready-to-eat meal right in a jar that just needs a bit of reheating before serving.

What Kind of Pressure Canner to Buy

Now that you know what pressure canning is, you’re likely chomping at the bit to get started! The beautiful thing about pressure canning is that it doesn’t cost very much money at all to get yourself up and running. In addition to the canner itself, you’ll also need some canning jars (like Mason or Ball jars), lids and rings (you can reuse the rings more than once, but you’ll need to buy new lids each time), a jar lifter, and some towels. That’s it!

Not all pressure canners are made alike, however.

First, there’s the dial gauge canner. These canners have a gauge on top that tells you the pressure inside the canner. They’re great for beginners because they’re easy to use and give you an exact reading. However, you do need to get them tested annually to make sure they’re reading accurately. 

Second, there’s the weighted gauge canner. These canners have a weight on top that regulates the pressure. They’re also known as “jiggler” canners because the weight jiggles and makes a noise when the pressure is at the correct level. These canners don’t need to be tested annually because they don’t have a gauge. They’re simple to use and work well for most canning needs.

Finally, there’s the electric pressure canner. These canners are a bit different from the previous two because they don’t need to be used on a stove. You plug them in and they do the rest. They’re a great option for those with limited stove space or those who want an all-in-one solution. Be careful when shopping for these models – there aren’t many that meet USDA recommendations, but they can be helpful because they don’t require you to make adjustments at high altitudes. 

One note of caution here – do not use a pressure cooker as a canner. While many people use these phrases interchangeably, the two are actually quite different devices and need to be used as intended. 

A Few More Tips to Consider

As you’re shopping for your pressure canner, you also need to consider your stove type. If you have a gas stove, you can pretty much use any pressure canner. 

However, if you have an electric stove or a glass stovetop, you need to make sure you get a canner with a flat bottom – ideally one intended for a glass-top stove. This will ensure that the canner makes proper contact with the heating element and heats up evenly.

Capacity is also an important factor. If you’re just starting out, a 16-quart canner is a good choice. It’s large enough to hold a good batch of jars, but not so large that it’s unwieldy. If you have a larger family or want to can in larger quantities, go for a 23-quart canner.

When shopping for a pressure canner, look for features like an easy-to-read pressure gauge, a release valve, and sturdy handles. Make sure the scanner is compatible with the jars you want to use (most canners fit both pint and quart jars and some even allow double-stacking of pint jars). 

Pressure Canning 101: Instructions

Pressure canning might seem intimidating at first, but really, it’s about as easy as can be! Follow these tips and you’ll be enjoying your newly canned food in no time. 

1. Sterilize Your Jars

The first step is to sterilize your jars. Make sure you clean them thoroughly with hot, soapy water and then place them in a hot water bath (the water should be boiling – you can also do this process in your dishwasher if it has a “sani” cycle you can run). Leave them in the water for at least 10 minutes to kill any bacteria that may be lurking about. 

One note here. When it comes to pressure canning, the type of jar you use is important. Make sure you’re using jars that are specifically made for canning – don’t try to reuse jars from store-bought food or other types of glass containers. You’ll also want to use new lids and rings to ensure a proper seal.

2. Load the Jars With Your Recipe

Next, it’s time to load those jars up with your recipe. Whether you’re canning vegetables, meats, or soups, you can find plenty of great recipes online or in canning cookbooks. Remember, it’s important to follow the recipe exactly as it’s written to make sure your food is safe and keeps well. 

3. Remove Air Bubbles and Clean the Rims

After your jars are loaded up with deliciousness, it’s time to remove any air bubbles that may have formed (you can do this with a plastic knife) and give the rims a nice, clean wipe down. Make sure you have adequate headspace and that you haven’t over- or underfilled your jars (your recipe will tell you how much space to leave).

4. Fill the Canner With Water

Now it’s time to fill up that canner with water. The amount you need will vary based on the manufacturer’s recommendations, so be sure to check your manual. In general, it will usually be around two to four quarts of water. 

5. Load the Jars into the Canner

Once your jars are filled, it’s time to seal them up and get them ready for processing. Place the lids onto the jars and secure them with the rings, making sure they’re snug but not too tight.

After you’ve filled your jars, go ahead and load them into the canner. Follow the manufacturer’s recommendations for how close together these should be. 

6. Put the Lid on the Canner and Lock it in Place

Next, put the lid on your canner and lock it into place. It should click when you do this.

7. Vent Steam for 10 Minutes

Before you start building pressure, you need to let some steam escape to create a proper seal and remove any trapped air. Let the canner vent steam for about 10 minutes before proceeding to the next step.

8. Close the Vent

Once the steam has been released, it’s time to close the vent. This is typically done with a weight in a weighted-gauge canner or the vent cover in a dial gauge type. Make sure the vent is securely closed before you continue.

9. Build Pressure and Start Timing

Now it’s time to start building pressure inside the canner. Follow your recipe’s recommended pressure level and let the canner come to the desired pressure before starting your timer. For example, if you’re canning chicken broth, you’ll want to get to 10 pounds pressure (and you’ll need to stay at 10 lbs for a full 20 minutes if you’re canning pints). 

Getting to the right pressure can take anywhere from five to twenty minutes depending on your specific recipe and canner.

10. Watch it Like a Hawk!

During the processing time, it’s important to keep a close eye on the canner to make sure it stays at the right pressure. If the pressure goes above the recommended level, that’s okay – just turn down the heat a bit to bring it back to the proper level. Don’t let it remain high, as you’re creating a sort of miniature-bomb on your stovetop! Not good. Turn the heat down a bit and you’ll be good to go. 

If the pressure gets too high, you don’t need to adjust your timing – however, if the pressure drops below the recommended level, you’ll need to restart the timer once it’s back up to pressure.

11. Shut Off the Heat – But Leave the Canner Where it Is

Once the processing time is up, turn off the heat and let the canner sit for a few minutes to release its pressure naturally.

Do not move the canner. There’s a lot of built-up pressure inside that little machine, and shifting the jars around can cause them to break (or cause you to get hurt). Just turn off the heat and leave the canner where it is. 

12. Wait for the Canner to Depressurize Before Removing the Jars

Don’t attempt to open the canner until it has fully depressurized. If you try to take off the lid and there’s still pressure inside, you’re going to be faced with a pretty nasty steam burn. Instead, wait until the pressure reads “zero.”

Then, after the canner has cooled down a bit, it’s time to remove your jars. Use tongs or a jar lifter to carefully remove each jar from the canner and place them on a towel or cooling rack to cool.

13. Let the Jars Cool and Test Their Seals

Allow your jars to cool completely before testing the seals. To test, press down on the center of each lid – if it doesn’t pop back, it’s sealed properly. If any jars haven’t sealed properly, they can be refrigerated and used within a few days, or reprocessed using the same steps.

How Many Jars Can a Pressure Canner Hold?

The number of jars a pressure canner can hold depends on its size. Generally speaking, a standard sized pressure canner can hold anywhere from 7 to 10 quart jars at a time. Some fancier models may even fit up to 12 jars! 

And if you’re using smaller pint jars, you may be able to fit a few more in there. Some models allow you to double stack pint jars, meaning you could get as many as 19 or 20 jars inside a canner. How cool is that? 

Just remember to always pay attention to the manufacturer’s recommendations. If you’re using wide-mouth jars, they may take up a bit more space in your canner, meaning you won’t be able to fit quite as many in there.

Resist the urge to overfill, too, even if you think they might fit. Overfilling your pressure canner can be a recipe for disaster, so be sure to double-check the manufacturer’s guidelines for how many jars your specific canner can safely handle.

A Few More Tips for Successful Pressure Canning

Before you go, check out a few more tips to help you be successful in your journey to pressure canning:

Altitude Makes a Difference

If you live at a high elevation, your boiling point is lower and your pressure canner will have to work that much harder to reach the proper temperature. Make sure to adjust your canning times and pressure settings accordingly to avoid any food safety issues. Most recipes will tell you exactly what you need to do here.

Acidity Matters

Another important factor to consider is acidity. Some foods, like tomatoes, are naturally high in acidity and can be safely canned using a water bath canner. 

However, low-acid foods like meats and vegetables need the higher temperatures and pressure of a pressure canner to kill off harmful bacteria. Be sure to follow a trusted recipe that includes the proper amount of acid (like lemon juice or vinegar) to ensure your canned goods are safe for storage.

Know the Difference Between Weighted and Dial Gauge Pressure Canners

While both canners operate similarly, they require different pressure settings and canning times. Always refer to your user manual and recipe for the correct canning instructions.

Not All Pressure Canners Are Created Equal 

It’s also important to note that not all pressure canners are created equal. You’ll want to invest in a high-quality canner that will last for years and provide accurate pressure readings. It’s worth the initial cost to avoid any safety issues and to have consistent canning success.

Test Your Gauge for Accuracy

And speaking of safety, make sure to test your gauge for accuracy before you begin canning each season. A faulty gauge can result in under- or over-processing your food, which can be dangerous. Use a trusted testing method or take your gauge to a professional for calibration.

Don’t Use Your Instant Pot to Pressure Can

Finally, while those fancy electric pressure cookers (like Instant Pots) may be versatile and convenient, they are not suitable for pressure canning. The temperatures and pressure levels are not sufficient for safe preservation, so stick to a traditional pressure canner for your canning needs.

Where to Find Pressure Canning Recipes

Now that you’ve got the hang of pressure canning, you’re going to need some delicious recipes to fill those jars. Luckily, there are plenty of resources available to help you on your canning journey.

Start at the bookstore. Many cookbooks, especially older ones, include sections on canning and preserving. You may even have some family recipes that have been passed down through the generations. These recipes have stood the test of time for a reason, so give them a try.

Another great resource is the internet. A quick Google search for “pressure canning recipes” will yield an endless array of options. There are countless food blogs, websites, and forums dedicated to home canning. Just be sure to stick with reputable sources, as canning is a science and not all recipes are created equal.

One of the best places to find canning recipes and advice is your local extension office. These offices are run by state universities and offer a wealth of information on all aspects of home canning. They may even offer canning classes or have knowledgeable staff on hand to answer your questions.

No matter where you find your recipes, be sure to follow them carefully and use the appropriate processing times and pressures for your altitude. And don’t be afraid to try new recipes – you never know what treasures you’ll uncover!