For at least 200 years, gardeners have been using a simple, reliable technique to preserve homegrown produce for much longer. But it wasn’t till World War II that canning (also known as bottling) really peaked as a way of improving food security.
Since then, canning has fallen out of favour a bit, but with more of us now growing our own it’s seeing something of a revival – and no wonder, because canning can lock in that just-picked freshness for up to 24 months! Want to have a go? Here’s how to do it!
You Can Can!
Can you can? Of course you can! Canning has always been popular with gardeners in the know, so it’s great that more people are cottoning on to this simple method of preserving the best of our harvests. This is a wonderful way to preserve produce that’s super-fresh and at peak ripeness. Don’t can anything that isn’t perfect. Set aside any blemished, slightly soft or otherwise suspect pickings to use as soon as possible.
Water bath canning is the most straightforward way to can produce. For that we’ll need little more than a large stockpot or canning pot, big enough to process several jars at a time. Many canning pots also include a simple rack to lower the pots in. If you don’t have a rack, just use a folded up dish towel on the base of the pot to lift jars off the bottom of the pot so they don’t rattle around too much, which might cause breakages.
![Water bath canning]()
Water bath canning is a straightforward way to preserve perfectly ripe harvests
You’ll also need some canning tongs to move the jars without burning your fingers; a wide-mouthed funnel, which will make it easier to fill the jars; a ladle; and a rubber spatula (do make sure it’s rubber or plastic, because a metal spatula could potentially scratch or chip the glass jars or react badly with the ingredients).
And, of course, we’ll need canning jars. The type with lids and bands do a great job of ensuring that all-important airtight seal, and the jars can be used time and time again, year after year. You can always add to your collection gradually to avoid too much initial outlay. They’re a really good investment and a handsome collection of canning jars, built up over time, is a fine thing indeed!
Sterilising Canning Jars
The first stage in the canning process is to sterilse our jars to minimise any risk of contamination. Give jars a good wash in hot, soapy water, followed by a rinse to remove the suds, then pop them onto the canning pot’s rack, lower them into the pot and fill with water so the jars are covered. Simmer for 10 minutes to kill any bad bacteria and other nasties. Handle jars with care throughout the canning process as they can be scaldingly hot!
Alternatively, you could pop your jars onto a baking sheet and sterilise them in the oven. Warm the oven up to 300ºF (150ºC or Gas Mark 2), then once it’s reached that temperature, hold it for 10 minutes.
![Sterilizing canning jars]()
Sterilising jars is key to ensuring canned food keeps safely for a long time
Canning jars are made of extra-strong glass, but don’t push your luck – keep the jars warm while you prepare your ingredients to reduce the risk of the glass cracking when you come to fill them with piping-hot produce.
Wash lids in warm, soapy water, rinse, and set aside till you’re ready. As the bands won’t be in contact with the food, they need no preparation.
Fill Your Jars
Water bath canning is fairly low-tech, simple way to can produce, but it’s only possible with either naturally acidic foods, or recipes that include some sort of acid such as lemon juice, to create a more acidic environment. Follow canning recipes to the letter, paying particular care to making sure that acidifying ingredients are included in the correct quantities to reduce the risk of serious issues like botulism which, believe me, we want to avoid!
If you’d like to can non-acidic foods try pressure canning – it involves a specialist piece of kit, but will greatly expand what you can can.
![Canned vegetables]()
Shelves of canned homgrown produce are a handsome sight!
When filling your jars, leave a half inch (1 cm) of headspace at the top so nothing touches the lids. You’ll often find that there are air bubbles when you fill the jar, and
we want to remove as many of these as we can. Use your spatula to lightly jiggle the produce to release the bubbles, and run it along the sides to dislodge any bubbles trapped on the inside of the jar. One you’ve done this you might need top up with a bit more of the hot liquid if the level has dropped.
Sealing Canning Jars
Give the threads of the jars a quick wipe to remove any splashes, and then place your lids on top. Get them on as squarely (or should that be roundly!?) as possible. Getting them properly aligned is important to get a good, tight seal. Then twist on the screw bands to hold the lids in place while they’re processed.
Lower the jars down into the hot water so that the tops of the jars are covered by at least an inch (2.5 cm) of water. Bring the water up to a rolling boil, then simmer the jars for 40 minutes.
![Jars of canned tomatoes]()
Lids will form an airtight seal as jars cool
Once time is up, turn off the heat and, after a few more minutes, carefully remove them from the water and onto waiting dish towels. All you need to do now is wait for them to completely cool back down to room temperature. It’s during this time that the magic happens! As everything cools, a vacuum is created which draws the lid in close and tight, creating a good seal. You might even hear popping noises from the lids as the vacuum develops.
Once they’re fully cooled, remove the bands – they’re not needed any more – and check that the seals have formed by pushing down on the lid, which shouldn’t have any give. If any of them haven't sealed, store them in the fridge and use them up as soon as possible.
Store the successfully sealed jars in a cool, dark, dry place where your fresh-picked, beautifully processed produce should keep for at least 12 months.
