The Secret to Airtight Glass Storage Jars

The Argon Tableware range of Glass Storage Jars with Airtight Clip Top Lids - Suitable for Fruits, Vegetables, Pickles, Seasonings and more

Browse any popular lifestyle blogging or social media platform today and you’ll no doubt be inundated by influencers up and down the internet talking about ‘x reasons why you totally NEED to start growing your own fruits and vegetables’.

Certainly, the art of the self-sufficient kitchen provides a lot of benefits:

Nutritional - Fewer chemicals; the food you grow can be eaten fresh from the ground as opposed to from a store after extensive time and distance spent shipping and storing.
Physical - Gardening keeps you active and exposes you to fresh air and sunlight. You may also find spending a little time around nature helps to ease stress and anxiety.
Financial - For the cost of a packet of seeds, a successful crop can continue to provide through multiple seasons, saving money on your shopping bill.

If your green fingers are itching to get involved in the ‘homegrown’ movement, one thing you'll need to consider is how the fruits (and vegetables) of your labour will be stored.

A New Craze, 150+ Years in the Making!

The practice of storing food in glass jars has been common since the mid-19th Century, when advancements in manufacturing allowed the containers to be mass-produced for the first time. Through the generations since, that practice hasn't really changed - take a stroll through any town centre on Market Day and you'll no doubt find scores of those very same jars stacked at the back of stall after stall.

So, what is it about the glass storage jar that makes it the go-to for 170 years' worth of farmers, jam makers and owners of vintage sweet shops?

Well, the main selling point is its ability to create and maintain an airtight seal around the lid, locking in freshness to keep the contents full of flavour and other goodness for far longer than your standard box or plastic wrapper.

That seal is created by a combination of two things: a ring of rubber or silicone pulled tight over the underside of the jar lid, and a metal wire clip mechanism that locks that lid in place. The majority of jars on the market use rubber rings - however, our Argon Tableware models use silicone, which is stronger, more durable and therefore designed to last a lot longer.

So far, so simple - but be aware; any glass storage jar you buy does not come airtight straight out of the box! There is a particular process you need to follow (conveniently called 'processing') in order to create that seal. It's fairly straightforward - essentially just boiling your jars in water a couple of times - but we have laid a simple step-by-step guide out for you below. Find yourself a recipe for homemade jam, marmalade or chutney and follow along for delicious, perfectly preserved preserve!

Eight Simple Steps to Creating an Airtight Seal for Jams, Marmalades, Preserves & Chutneys

What You'll Need...

Jars - Obviously. The size will depend on what you’re making and how much. Fortunately, our Argon Tableware collection offers a wide range that is sure to cater to whatever your heart and hunger desire!
A Large Pot - Professionals and mass-manufacturers can source something called a Water Bath (essentially a big bucket); for the novice or home jammer, any large cooking pot will do. Again, the size will depend on the jars you’re using and how much you’re planning to make - keep in mind, though, that you’ll need to have room for 1-2 inches of water ABOVE the tops of the jars.
A Less-Large Pot - For sterilising the silicone rings that go around the lids of your jars.
Oven Gloves - Vital for handling hot jars. Again, if you prefer, you can get hold of specialist ‘jar tongs/lifters’ to remove your fingers from the equation entirely.
A Heat-Proof Surface - Such as a Worktop Saver or Trivet. This will protect your counters and tables from being scorched by hot glass.
A Ladle - To scoop your stock into the jars.
A Day - Your jars will need to cool for 24 hours after processing, so make sure you allow enough time for this to happen!

Step One: Check your jars!

It sounds obvious, but it’ll save you a LOT of time and heartbreak. Check the condition of the jars you’re going to use. If they appear chipped, cracked or broken in any way, set them aside - they will not work for this process!

Step Two: Remove the seals

You’ll process these separately from the jars themselves.

Step Three: Sterilise your jars

Place as many empty jars as will comfortably fit into your pot or bath and fill with cold water until completely submerged. Bring the water to the boil and heat through for 10 minutes.

Step Four: Sterilise your seals

Place your silicone seals into a separate pan and fill with four inches of water. Heat to 85°C and simmer for 10 minutes. Turn off the heat below both the seals and the jars and cover each pan to keep warm until ready to fill.

This is the point where you should make your jam, marmalade, etc. Take your time! I'll just wait here.

Step Five: Filling

Carefully remove one of your jars from the warm water and place on a heatproof surface. Use a ladle or large spoon to transfer your preserve into the jar. Best practice is generally to leave around a quarter-inch of empty space at the top of the jar, though this may vary depending on your recipe!

Use a non-metallic spatula to remove any air bubbles by running it around the inside edge of the jar between the preserve and the glass.

Step Six: Apply the seal

Carefully remove one of your seals from the pan and stretch it over the lid. Close it up and use the wire clasp to lock in place. Repeat steps 6 and 7 as necessary for your other jars.

Step Seven: Process your jars.

Discard the water from your pan or bath, then refill with fresh cold water. Bring to the boil and heat through for 30 minutes. The application of additional heat to your preserve is what helps to create the vacuum seal between the jar and the lid.

When you submerge your jars at this point, it is recommended that they do not touch the bottom of the pan. Specialist “canning racks” are available; however, if you do not have one of these, you can layer your jars on top of a tea towel instead.

Step Eight: Cool down

After 30 minutes, turn off the heat and leave your jars to cool untouched for 24 hours. Once those 24 hours have passed, you can check the seal by undoing the wire clip lock and lifting your jar (carefully!) by the lid. If it stays in place, success!

Don't forget to label your jars with our chalkboard stickers or slate hanging tags: perfect tools for organisation (as well as showing off)!

Has this article helped you hop on the homegrown bandwagon? Got any recipes for delicious jams, pickles or other preserves you'd like to share? Let us know in the comments or tag us on social media!

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