Preserving is simply a broader term that describes treating food with heat, acid, smoke, or salt (or some combination of those) in order to prolong its shelf life by destroying or inhibiting the growth of active bacteria; freezing and vacuum-sealing are other methods of preservation.
The preserving umbrella encompasses everything from pickled vegetables and jams and jellies to jerky and smoked salmon, though we certainly tend to associate it most with produce (fruit preserves being one specific example; they tend to have larger chunks of fruit than jam or smoother-still jelly).
Canning is the branch of preserving that—in a home kitchen—involves sterilizing glass jars, filling them with fruits, vegetables, or meat, and cooking them in a hot water bath or pressure canner. “Preserving” is sometimes used interchangeably with canning, which can be a bit confusing, especially since you can still preserve things in those iconic mason jars without actually canning them, including jams, jellies, and pickles; they just won’t last as long and will need to be refrigerated.
Related Reading: How to Quick Pickle Anything
How Do These Methods Work?
Homemade jam and jelly rely on sugar and acid (often in the form of lemon juice) to inhibit bacteria and prolong the shelf life of the starring fruit or veg (this is why low-sugar jams will spoil faster once opened). Quick pickled vegetables rely on a mix of salt and acid (usually vinegar) to do the same—adding these ingredients will make the produce last at least a few weeks if not months, but they’ll still need to be stored in the fridge since they haven’t undergone a canning process.
If you do take the next step and can these jams, jellies, or pickles, they’ll be shelf-stable after the high heat treatment, which kills more bacteria and also seals the jars. Canned goods will last for a much longer time too—though once you open a jar you’ll still have to store the leftovers in the fridge and consume them within a month or so.
Ball 9-Piece Canning Starter Kit, $14.83 from Walmart
This kit includes four half-pint canning jars, a funnel, a bubble remover, a jar lifter, a trivet, and pectin for jams and jelly.
Related Reading: Essential Canning Supplies to Stock Before You Begin
Home canning is a cooking paradox. It’s simultaneously simple (a food’s life span is extended) yet complicated (it requires a precise amount of acid and heat). Get it right, and you’ll have flavorful whole fruit and tasty spreads, sauces, and condiments for a full year; get it wrong, and you’ll have a jar of mold and funk.
The USDA advocates two canning methods: the boiling water method (or water bath canning) and pressure canning. In the boiling water method, all the food gets packed in jars, then placed in a hot water bath for a specific amount of time. This method is safe, easy, and doesn’t require that you buy a steamer. You can use a stockpot and steamer rack you already have as long as they meet the guidelines here, but you will still need a few specialized tools like a jar lifter to make the process easier.
Water bath canning should only be used for high-acid foods (meaning they have a pH lower than 4.6) such as fruit and tomatoes. (You can use low-acid vegetables if you pickle them first, since that makes them stable before canning.) If you’re not sure about the pH of your produce, test it with some litmus strips à la high school chemistry. This may seem overcautious, but it will ensure you don’t have unwanted occupants multiplying once the food is processed.
Pressure canning must be used for low-acid foods, including most vegetables and meats (think green beans, corn, chili con carne, and homemade spaghetti sauce with ground beef). You should not use a pressure cooker like an Instant Pot for this method; naturally, some people have (and some Instant Pot models actually have canning settings), but this goes against USDA guidelines.
To safely pressure can, you need a pressure canner, a special piece of equipment with a pressure gauge that subjects the contents to steam heat at a much higher temperature than boiling water. Pressure canning comes with other caveats and warnings as well, which is why water bath canning is the usual entry point for beginners.
In all cases, since improper home food preservation can be dangerous, it’s important to find a tested canning recipe and follow it precisely. And always use the proper canning method indicated by the recipe.
Preserving & Canning Recipes
Here are a few examples that help further illustrate the difference between preserving and canning, as well as the two different canning methods.
Jam and jelly are great places for beginning canners to start, and making them is an easy way to preserve fruit for the shorter term too. Our Fragrant Blueberry Jam recipe includes canning instructions for a jam that can be stored in the cupboard for up to a full year—but if you don’t want to keep it that long, you can skip the canning process and simply store the spread in the refrigerator for up to 1 month or in the freezer for up to 3 months. This is true of any fruit preserve recipe.
Summer berries and stone fruit aren’t the only candidates for canning, of course. If you love that jellied log of cranberry sauce at Thanksgiving but don’t love the high fructose corn syrup in the commercial brands, make your own! Get the Homemade Canned Cranberry Sauce recipe. (And jelly haters, never fear: You can make Whole Berry Canned Cranberry Sauce too.)
Canned tomatoes are a pantry staple that you might not think about making at home, until you have a glut of perfect summer tomatoes you can’t possibly eat all at once. Use the water bath method to preserve them and you’ll have a flavorful base to use year round in sauces, soups, and more. Our Canned Tomatoes recipe packs the whole fruit into jars with their own juices, but you can also make homemade tomato puree and paste.
When it comes to homemade spaghetti sauce, you can process it with boiling water too—unless you want to add meat, in which case, you must use the pressure canning method. Either way, you should also stick closely to the recipe (as is true with all canning recipes), since adding certain things like fresh herbs and vegetables can alter the pH and make the end result unsafe to store. Get the Canned Spaghetti Sauce recipe.
Quick pickles are a snap to make since you simply pour a hot brine over the vegetables in question; they keep in the refrigerator for at least a week and often much longer (just be sure to keep them submerged beneath the liquid and don’t contaminate the contents by fishing them out with your fingers). Canning pickles, of course, makes them last much longer, and they don’t need to be refrigerated until you open a jar. This Canned Dill Pickle recipe details everything down to the ideal cucumber size (with a note on bread and butter pickles too); because the low-acid cucumbers are pickled prior to canning, the hot water method is all you need.
Related Reading: What Is the Difference Between Pickling and Fermenting?
This pickled cabbage recipe (which also features cucumbers and tomato) can be made with a water bath canner, thanks to the acidic brine. If you’ve never had chow chow, prepare to fall in love with this tangy relish, which you can use like slaw or pickles, and anywhere you might use sauerkraut. Get the Chow Chow recipe.
In addition to preserving produce and meat, you can even can your own beans! Since they’re low acid, you do need a pressure canner. Start with whatever kind of dry beans you like and your pantry will be well-stocked through the winter. Get the Canned Beans recipe.
Preserved lemons are a fabulous addition to the standard roster of pantry staples that originated in the Middle East and often show up in Moroccan dishes. While you do need to sterilize the jars, the preservation happens thanks to a heavily salted brine—no hot water bath required. Our Spiced Preserved Lemon recipe adds bay leaves, cinnamon, allspice, cloves, and coriander, but if you want to skip the warm spices, the end result will be even more versatile.
Canning can definitely be a bit daunting, but there are some first-rate resources out there to help you get through it. Here are some, both online and in book form:
- National Center for Home Food Preservation
- Food in Jars
- Simply Canning
- Canning Across America
- Well Preserved
- “Canning & Preserving for Dummies” by Karen Ward
- “Ball Complete Book of Home Preserving” edited by Judi Kingry and Lauren Devine
- “Blue Ribbon Preserves” by Linda J. Amendt
Header image by Chowhound.