This Homesteading Mom of 11 Pressure Cans Hundreds of Jars of Food Each Year. She Thinks You Should Too.

Carolyn Thomas sees pressure canning as a great way to preserve her homestead-grown harvest and feed her family good food on a budget. (Courtesy of Homesteading Family)

Carolyn Thomas understands the apprehension. To the uninitiated, pressure canning can seem a downright frightening process. It’s all too easy to remember the time Great-Aunt Agatha’s pressure canner exploded and sent shards of glass and spaghetti sauce flying in all directions.

Fortunately, most pressure canners made within the past 20 years have fail-safe mechanisms in place to prevent such catastrophes. When done correctly, pressure canning is one of the safest and most efficient ways to preserve the harvest.

Mrs. Thomas’s desire to pressure can was “born out of necessity“ and wanting to feed her family ”really good food without things getting too expensive,” she said. As the mother of 11 children and co-steward of a 40-acre north Idaho homestead, she needed a way to make her meat and vegetable harvest last.

Josh and Carolyn Thomas with their children. (Courtesy of Homesteading Family)

“Being in a place where we can’t grow year-round, we had to preserve the food to get it on our pantry shelves,” she said.

In the early 2010s, armed with a vintage canning book from the 1970s, Mrs. Thomas set to work learning how to can her family’s food. She has now been successfully pressure canning for more than a decade, and puts away 500 to 600 jars of farm-raised meat, stews, sauce, and various vegetables every year. She has taught classes and published e-books on the subject under the banner of Homesteading Family and the School for Traditional Skills, both of which she co-runs with her husband, Josh.

But her early attempts weren’t without stumbles.

Ms. Thomas cans 500 to 600 jars of homegrown food every year. (Courtesy of Homesteading Family)

Understanding Canning Safety

One thing the 1970s book lacked was updated information on the safety requirements of pressure canning. Failing to pressure can food safely can result in potentially deadly consequences.

Bacteria, yeast, and mold can thrive in any type of food environment. While some, like probiotics, are cultivated to benefit your gut, others aren’t so friendly. Fortunately, most molds and yeasts are easy to kill with heat. Bacteria, however, are a little different.

When canning foods like tomatoes, which are extremely high in acid, bacteria can’t survive. That’s why traditional hot water bath canning is so effective for high-acid foods. The boiling water kills molds and yeasts, while the acid takes care of the bacteria.

Ms. Thomas with her homegrown produce, which she cans to feed her family year-round. (Courtesy of Homesteading Family)

At lower acidity levels, however, harmful bacteria such as botulism can survive and multiply, and more heat and time are required to reliably kill them. Low-acid foods such as potatoes and meat need to be held at 240 to 250 degrees F for an extended period of time, and thus cannot be canned in hot water baths, which reach a maximum temperature of 212 degrees Fahrenheit (water’s boiling point). To go higher, you’ll need a pressure canner. Pressure canners reach high temperatures by trapping heat inside a pressurized container and sustaining that temperature for as long as it takes to kill the bacteria.

This was the vital information that Mrs. Thomas lacked in her early canning efforts. Unaware of the potential dangers, she had been hot water bath canning all of her low-acid foods. It was only when she purchased an up-to-date canning manual that she realized just how much danger she’d put her family in.

“I was horrified. What I had been doing could literally have killed off my entire family,” she said. This newly acquired knowledge prompted Mrs. Thomas to dive deep into canning safety.

“While canning safety can seem really daunting, if you can get a grasp on the basics of the pH, and follow approved methods, it’s actually incredibly safe,” she said.

Ms. Thomas cans meat raised on her family's homestead. (Courtesy of Homesteading Family)

Understanding the Pressure Canner

Then, there’s the fear surrounding the pressure canner itself.

“It’s an intimidating piece of kitchen equipment. It sits there and rattles and has steam going everywhere. It’s an intimidating thing to learn at the beginning, especially if you’re not used to machinery,” Mrs. Thomas said.

Pressure canners are stovetop tools that boil water in a sealed chamber to create pressurized steam. Lidded mason jars packed with either raw or precooked food go into the chamber. The heat created by the steam sterilizes the food in the jars, while also giving the jars an airtight seal for long-term storage.

Mrs. Thomas uses a propane field camp burner or her gas range as a heat source. Home cooks with electric stoves will need to check the owner’s manual to see if their model is rated for pressure canning. Those that aren’t could easily crack with the extended heat.

To measure the steam, pressure canners have either a numbered solo dial gauge or a dial-weighted gauge combo. The solo dial maxes out at a pressure of 11 pounds per square inch (psi) at sea level. It can be regulated by turning the heat up or down. The major downside to solo dials is that they require yearly calibration, which can be inconvenient for those without the tools to do so.

Weighted gauges don’t require any sort of yearly recalibration, making them far more beginner-friendly. This is the type of canner Mrs. Thomas uses. The dial-weight combo adds a physical weight to the steam vent on the canner. This small weight jiggles to release any pressure above the desired amount. Pressure requirements change depending on elevation, so be sure to consult the canner owner’s manual to see how much weight is required for your elevation.

Mrs. Thomas recommends All American Pressure Canners.

“You can hand them down to your children; they’re so well made,” she said.

Another great tip is that a pressure canner can be used as a water bath canner as long as you don’t lock the lid to pressurize. It’s two canners for the price of one!

Cans in the pressure canner. (Courtesy of Homesteading Family)

What Not to Pressure Can

Vegetables and meats are excellent candidates for pressure canning. Mrs. Thomas doesn’t recommend pressure canning fruit because “most are too delicate and overcook when run through the canner,” she said.

Pure oils, fats, dairy, eggs, and grains aren’t safe to can because of their extremely low acidity and moisture levels.

The National Center for Home Food Preservation is an excellent resource for all things canning-related, including safety tips, canning times, and pressure guides for altitude. The “Ball Blue Book Guide to Preserving” is also a perennial favorite.

Tips on Storage

Label the jar lids with the contents and year they were canned. As the food is now shelf-stable, it can be stored in a standard pantry out of direct sunlight. Ensure that the jars never freeze or reach temperatures over 120 degrees Fahrenheit. Either condition breaks the seal on the canning jars and ruins the contents.

As far as shelf life goes, they are theoretically good as long as the seal remains intact.

“I’ve heard stories of jars lasting up to 30 years,” Mrs. Thomas said.

This longevity doesn’t, however, translate to how long the food remains nutrient-dense. Ideally, consume pressure-canned food within a year of being canned. This also makes room in the pantry for next year’s harvest.

“It’s an amazing way to have food ready at your fingertips,“ Mrs. Thomas said. ”You save a lot of money on your grocery bill and time on busy nights.”

Ready to try it yourself? Mrs. Thomas shared a beginner-friendly recipe: Raw Pack Pressure Canned Green Beans