Editor’s note: This week’s article is written by Maggie Cooper, wife and thinking partner of regular columnist Jay Cooper.
Like many of you, Jay and I grow quite a bit of the food we eat during the spring/summer growing season. And like many of you, I suspect that you sometimes end up growing more than your family can use immediately. There are several ways to preserve your harvest so that you and your family enjoy it all year long. Today we are going to talk about canning.
Some of the crops we grow and can each year are tomatoes, peppers, jams from peaches, apricots, nectarines, black berries and raspberries, grape juice and jelly, applesauce, cherry pie filling and others that vary depending on our crop choices for the season. It’s very rewarding to get a jar of my own tomatoes out of the pantry in January and use it as the base of a hearty soup for lunch. We also have a bed and breakfast in our home and our guests are always impressed with the homemade jams we serve for breakfast along with homemade honey and oat bread that has been toasted.
With an incredible array of foods available in the canned food section of the grocery store, and all the sealed bottles and jars of sauces, relishes, pickles, condiments, and toppings, it’s hard to imagine a time when none of this was available.
A hundred years ago, grocery shopping was quite different than today. Only fresh food to be used right away, or staples like sugar and flour, spices and the like, were available for purchase. So families were forced to try to preserve what they grew or killed in the wild or from their herds. My mother was born in 1916 in Phoenix, Arizona, and her home didn’t get electricity until she was in high school. Not only did they struggle to survive the 105-plus-degree summer temperatures without so much as a fan, but they had to try to preserve what they could through purchasing blocks of ice for their ice box or through canning. Imagine my poor grandmother canning food over a wood-burning stove in Phoenix in July!
Before people had the ability to can foods (seal them in containers that allowed them to be stored for a long period of time unrefrigerated) the choice of foods was limited to fermented foods, freshly harvested or butchered items, or items kept cold in cold weather or iced down. We visited an Amish farm in Ohio years ago that was part of a particularly strict Amish sect. They were still using a dugout area in the stream to keep their perishables preserved.
Did you know the process of canning was discovered as a result of the French Revolution? France found itself fighting just about every other country in Europe. The government of France offered a prize to any inventor who could create a better way to preserve food in order to supply it to the military in the field. After experimenting for over a decade, Parisian distiller and Chef Nicholas Appert won the 12K franc prize in 1809 with a process that became known as “appertizing.” Food was sealed in champagne bottles (who knows how they got food in there or more importantly, how they got it out!) and heated in boiling water. The heating process killed the germs, which was a bonus that Appert didn’t even realize, and the bottles could be transported to the battlefield without spoiling for months or even years.
A bit later, an Englishman named Peter Durand absconded with Appert’s idea and obtained a patent — with a notable improvement. He used metal containers. The first cannery in England opened soon afterward, putting food in canisters made out of tinplated steel. So, the term “tin can” is actually a takeaway from the words “tinplated” and “canister.”
Today, home canning is done primarily in molded glass jars with lids that can seal when the contents are heated to a specific temperature. Originally known as a Mason jar, it was named after John Landis Mason who first invented and patented it in 1858. A removable metal lid is laid on the top of the jar once the heated food is inside, and a threaded ring tightens it down so that it will seal during the heating process. Once complete and the lid is sealed to the jar, the ring can actually be removed until the jar is opened. Then any remaining food will need the lid and ring reapplied for storing in the refrigerator.
Why can properly canned foods be stored at room temperature? We now know that we can kill germs and micro-organisms with heat. That’s why we boil water before drinking it if we think it might be contaminated. The canning process heats the food to a temperature that destroys micro-organisms that cause food to spoil. During this heating process air is driven out of the jar and, as it cools, a vacuum seal is formed. This vacuum seal prevents air from getting back into the product bringing with it contaminating micro-organisms.
The boiling-water-bath method is safe for tomatoes, fruits, jams, jellies, pickles and other acidic preserves. In this method, jars of heated food are placed in a large canning pot, completely covered with boiling water (212°F at sea level) and cooked for a specified amount of time. A chart of these times for specific foods can be found in most canning books.
Pressure canning (using a pressure cooker) is the only safe method of preserving vegetables, meats, poultry and seafood. Jars of food are placed in 2 to 3 inches of water in a pressure cooker, which is heated to a temperature of at least 240° F (at 10 pounds of pressure). This temperature can only be reached using the pressure method. A microorganism called Clostridium botulinum is the main reason why pressure processing is necessary. Though the bacterial cells are killed at boiling temperatures, they can form spores that can withstand these temperatures. The spores grow well in low acid foods like meats and vegetables. When the spores begin to grow, they produce the deadly botulinum (botulism) toxins.
Here’s some simple tips I’ve learned during my years of canning. First, heat your canning jars, after washing in hot soapy water and rinsing, by placing them on a cookie sheet in a 200-degree oven for at least 15 minutes before using. The jars need to be as hot as the food going inside.
While you’re at it, place your canning lids in a pan with simmering water so they are sanitized and hot when they are placed on top of the hot jar.
Always have sugar pre-measured when canning jams or other food where you will add sugar. The timing is precise and you don’t want to have to interrupt the process by measuring.
It’s critical to follow a verified canning recipe to the letter. Make sure that you process your food for the exact time the chart recommends for your altitude. Know your altitude before you begin!
As you remove jars from the water bath or pressure canner, place them on a thick towel on the counter. As they cool, you will hear them “pop”. When all the jars have cooled to room temperature, you can test the seal by gently pushing on the center of lid. If it is properly sealed, it will not make a popping sound. If the lids flexes, making an “oil can” sound, put the jar into your refrigerator and use it in the next few days.
Remember, the 2017 Spring Expo is coming up on March 4th! With the gardening season coming at us so quickly, this is a great way to get your “head in the game.” There’s a total of six great subjects being covered, as well as a keynote class on how to have the best lawn on the block!
You can get more information in the Happenings section elsewhere in this paper. Jay and I plan to be there (in fact, Jay is presenting one of the classes) and I hope to see you there!
Jay Cooper can be contacted at firstname.lastname@example.org, or you can visit his channel at youtube.com/dirtfarmerjay for videos on the hands-on life of gardening, shop and home skills, culinary arts and landscaping.