Canning 101: Preserve the Harvest & Your Wallet
Canning isn’t just for your grandmother anymore.
Whether you’ve got a survivalist bunker or you’re a foodie crying because the last fresh blueberry dropped off the bush, canning is for you. Canning and food preservation fed Napoleon’s armies, and kept homesteaders from cannibalism throughout American history.
For me, canning isn’t matter of life and death–if I were a pioneer, I’d most certainly be dead. Canning falls somewhere between earth-loving sustainability and food snob.
What started as a budget craft quickly became an obsession. I waste less and eat better every year.
Canning is one of our grandparents’ arts we cannot let die.
Why should I can when the good Lord invented grocery stores?
Because you can…
- Save food in season. This is when it’s best and cheapest. It’s when nature intended us to eat it. It’s when it tastes best.
- Control the ingredients and quality. Don’t want a lot of salt? Don’t add it. With canning, you can eat without all the additives and junk.
- Go shelf shopping. Ever have one of those nights where you just don’t know what to cook? Canning brings the grocery store home. Jams, broths, sauces, salsas, meats, soups, chili, and veggies–all these things are at your fingertips, made by you.
- Gift inexpensively. Chuck a few jars in a basket, tie a bow around it–instant gift. A few dollars worth of Mason jars are far less expensive than a fifty-dollar gift basket, and people will think you’re a magician. “You made this?” Yes, indeed.
But first… the basics
Canning is relatively simple but done wrong, people die. Sneaky things grow in jars left at room temperature. You’ve got to kill them all and seal them right.
Which kind of canning do I need?
There are two types of canning–water bath canning and pressure canning. The one you choose depends on the pH of the food.
Water Bath Canning
Water bath canning is for higher acid items like jams, and tomatoes. The acid stops certain bacteria from growing and the rest can be killed at the normal sea-level boiling temperature of water–212º Fareineit or 100º Celsius. Water bath canners are just giant pots with racks in them so you can lift out the jars easily. You can use a soup kettle to can a few jars of jam, but you probably don’t have one that’s big enough to mass produce.
You must have a pressure canner to safely preserve low-acid foods such as soups, meats and most vegetables. A pressure canner is a special piece of equipment, a canner that adds pressure, raising the boiling point to a temperature where potential contaminants like botulism are killed. Botulism can survive your 212º assault.
Pressure canners are also pretty simple but they’re specialized equipment and a bit more costly. A pressure canner is NOT a pressure cooker–never confuse the two. Do NOT use your Instapot for this purpose!
A pressure canner has a weighted gauge on top that adds pressure, allowing the water to get to up to 240º degrees. Food gets processed much longer, according to the ingredient in the recipe that needs the most processing. If the water temperature and pressure falls below the temp even for one second, you’ve got to start that timer again. This is why pressure canning is a bit tricker.
There are a couple of common types of pressure canners–some have rubber seals, and some screw down. You can often get them at a discount on Ebay or other sites, but if you get one used, you must know how to check all the parts, so bring it to someone who’s canned to have a look. If any of the parts or seals looks old or cracked, contact the manufacturer of your pressure canner for replacement parts, gaskets, or seals.
I check mine often.
Today, we’re starting with water bath canning. I’ll do a separate post on pressure canning. Meanwhile, if you must can your beef soup, read this.
Before you can a single berry, repeat the canning creed with me:
“I will pay attention to the rules of canning at all times. Even if my middle name is ‘Picasso’ I will save my art and creativity for another time and follow the directions exactly.
I will follow the rules of kitchen safety, equipment safety, and sterilization at all times.
If I even think I’ve messed up a batch, I will put it in the fridge and eat it or throw it out, even though I hate to waste.
I will not experiment or gift unsafe food to my friends or enemies, and I will never EVER use an heirloom family recipe for canning without checking with a master canner or food scientist, even if my grandmother ‘Did it safely for decades.’
I will measure, stir, boil, and time all the steps of my recipes and use the required amount of headspace.
If a jar bubbles and doesn’t ‘pop’ I will put it in my refrigerator and eat it right away. I will not put it on my pantry shelf.
And when I gift items, I will always, ALWAYS demand the jars be returned.”
Now that you’ve been sworn in, let’s continue with canning history…
Napoleon Bonaparte was fighting everyone in Europe, and he got hungry. Since he was French, he couldn’t eat any old MRE (MREs hadn’t been invented yet…), he put out an award for scientists to invent a method of preserving fresh food for transport. Chef Nicholas Appert–patriot and foodie–started preserving food in champagne bottles–which seem pretty French to me, but smash in transport, and so the tin can had to be invented. Tin can trivia: the can opener wasn’t invented until later. Scientists do have a sense of humor.
What started as a military invention that let soldiers to use their bayonets to stab open tin cans made it to our kitchen in the form of the Mason jar you know and love. Canning became an art that was nearly lost as industrial food took over the world.
Now, we have tons of old recipe cards from our friends and families and prize-winning fair cookbooks.
These are not safe. Just because your grandmother did it, doesn’t mean you should, too.
Canning recipes must be tested and the science verified to guarantee you’re not going to die. Sure, you can get lucky canning things with dairy and flour (NOT RECOMMENDED WITHOUT A COMMERCIAL KITCHEN AND MASTER CANNER KNOWLEDGE) but if you do, ask yourself, “Do you feel lucky?” Then, be safe.
What is safe?
Any recipe that has been tested and included in the Bible of Canning, the Ball Complete Book of Home Preserving--also known as the “Ball Blue Book” is safe.
You may also trust any recipes from your local “extension school” (agricultural school at a food science university) or through a master canner.
A master canner is not your grandmother, by the way. It is a level of expertise. Master canners take exams, much like master gardeners. Master canners are trained, know food science, and are generally extremely happy to pass on their craft because not many people want to hear about wilted carrots in Weck jars. They get lonely. Look for them–treasure and appreciate them when you find them.
Let’s get started…
Supplies for A Simple Jam:
- A water bath canner. This is usually a black enamel pot. It comes with a rack for pulling up jars. You can buy one at a yard sale or on Ebay cheap. They’re easy to find. If it has rust, pass. Get one with the enamel intact.
- A jar lifter. It costs a dollar, and will keep you from being burned when you take the jars out. You can totally find these at old person garage sales.
- Mason jars or Weck Jars. I started with Mason Jars and keep plenty of rings and bands on hand, but I discovered the Weck jar recently, and am switching over. Those are the European glass jars with the reusable rings. Today, we’re using the Mason jar because it’s easier and more available for beginners.
- Lids and bands. These are cheap. If you dry your screw-top bands right away, they can be reused. Never reuse the flat rubber seal top for canning, but you can keep some on hand for storing leftovers in the fridge.
- Towels and clean space. You’ll use clean towels to wipe any food spills off the side of your jars prior to placing the lid on and canning. Please keep this part of the operation sterile.
- A wide-mouth funnel. I use it every day of my cooking life, but it’s especially amazing during canning time. I can fill jars without making a ton of mess.
10 Simple Steps to Water Bath Canning
Here’s a simple process guide. Make sure to use an approved recipe. I’m doing blueberry jam here…
How to can your favorite jam:
- Prepare your recipe. (I’ll be adding some to this site)
- At the same time as you are preparing your food, sterilize your Mason jars. To do this, boil in your canner. Leave them in the water until just before it’s time to fill them, then use your jar lifer to remove and dump the water. Be very careful with this if you’re not used to canning. Keep the boiling water in there for canning time.
- Fill the jars with your recipe as soon as you finish cooking–do not let your recipe cool or leave this until later. That’s where bacteria forms.
- Leave the required amount of “head space” in your jar. Headspace is empty space between the jar and the lid. Most recipes call for 1/4 inch to 1 inch of headspace. You’ll learn to judge it, but you’ll want to come very close as you’re learning. If you have too much or too little headspace, you won’t get a good seal. Don’t worry if it looks less filled after you can–the recipe accounts for that. Make sure you don’t have any bubbles in your jar that will give you extra headspace. If I see any, I get them out with a sterilized chopstick or knife.
- Jams and jellies: 1/4 inch of headspace
- salsas and relishes: 1/2
- veggies and low-acid canning (this is pressure canning) 1 to 1 1/4 inches)
- Wipe the top of each jar to make sure no food is around the top.
- Sterilize the lids and bands, and place the lid on the jar, then place the band on the top, screwing it tight, but not “I can never get this off” tight.
- Using the jar lifter, put each jar back in the canner, and process for the amount of time the recipe requires. Don’t start your timer until the water in the canner is boiling again.
- After the time has elapsed, leave the jars in the boiling water to rest for five minutes, then lift each out with the jar lifter, and place on a towel laid out on your counter where they won’t be disturbed until they cool–overnight or about 24 hours.
- Then, label each jar. Make sure you put the date, year, and contents.
- Keep a canning journal and log each batch and the quantity you make. This way you can ramp up production of things you run out of, and cut back on things you thought you’d love but didn’t use.
That wasn’t so hard, was it?
Start your canning with a simple recipe like jam with inexpensive, in-season fruits. You’ll get the flow and feel confident with your canning skills. Once you feel good about water bath canning, you may get the urge to start canning everything in sight.
If so, make your requests, and I will put them on the site for you!
If you have any specific requests for a canning demo or recipe, contact me at firstname.lastname@example.org and I’ll make that happen in a future post. If you love to can and want to submit a recipe or guest post, we welcome your genius, too. Send your post or photos and we’ll get them up and give you all the credit you deserve.