If you’re lucky enough to have found some canning jars with glass lids and rubber seals, you may be looking to do some water bath canning with them. The thing is, though, these jars are a little foreign to the new generation of canners.
In this article, I’m going to walk you through how to use canning jars with rubber seals and answer your most commonly-asked questions, so your canning goes off without a hitch.
In a hurry? Here’s the quick guide:
To use canning jars with rubber seals, fill your jars, then place the rubber seal on the mouth. Pull the lid down and use the clip hinge to clamp it down. Water bath as usual. Keep the jar clamped shut for 24 hours to fully seal.
While these jars seem to be the most common rubber-sealed canning jars, there are several other jar designs out there that require different canning methods. You may be interested in debates surrounding how to can with these jar varieties and which is the safest, most effective method.
All of this and answers to your most commonly asked questions are still to come.
Table of Contents
Using Canning Jars With Rubber Seals: Jars With One Clamp
To use jars with rubber seals, first fill your jar. Second, place the rubber seal on the mouth of the jar and pull the lid down. Clamp it shut with the front clip hinge, do the water bath, then leave the jar undisturbed for 24 hours while it fully seals.
To can with this method and with your rubber-sealed jar, sanitize the jar, the lids, and the fresh rubber seals. Prepare your contents and fill your jar. Note that some suggest you’ll need to leave a little more headspace than suggested for jars with metal canning rings because there’s more than one area for the contents of the jar to interfere with the seal.
I would personally suggest going by the recipe’s instructions for headspace unless you encounter problems.
After your jar is filled, make sure the mouth is clean, then place your rubber seal on top. Put the lid down, and then secure the front clip hinge. From this point, you will do a water bath as usual. When you remove your jar from the water bath, it will have to sit for 12 to 24 hours for the seal to take.
Using Canning Jars With Rubber Seals: Jars With Two Clamps
To use jars with rubber seals and two clamps, first fill your jar as normal. Then, secure your front metal clip onto the lid and do the water bath. After you remove your jar, pull down the second clip and let the seal take over the next 24 hours.
For this variety of glass jars with rubber seals, things get a little more complex. These jars are not as easy to find or buy, but many have stood the test of time and are still usable for water bath canning.
To can with this method, sanitize your jars, their lids, and your fresh rubber seals. Fill the jar with its contents, make sure the lip of the jar is clean, then place your rubber seal on the mouth. Pull the lid down, then secure one of the clamps by pulling it over the top of the glass lid.
Your second metal clamp will still be partially pointed up. Don’t put this part down yet, as that will fully seal the jar.
Water bath your jars as usual. When you remove the jar, you’ll pull the second metal clamp down, so it is resting on the shoulder of the jar. At this point, one of your metal clamps is firmly on top of the lid, and the other is in the down position. This is fully sealed. Let it rest in this position for 24 hours as the seal takes.
It’s interesting to note that there has been some debate about whether you can fully seal these jars before putting them in the water bath. Some research suggests that fully sealing them doesn’t interfere with the air escaping, and the contents of the jars are equally sanitary.
For the most part, everyone still abides by the half-sealed method.
How To Sterilize Glass Jars With Rubber Seals
To sterilize glass jars with rubber seals, first wash the jars, their lids, and the rubber seals with hot, soapy water. Then, bake the jars and their lids at about 180 degrees Fahrenheit for 15 minutes. Boil the rubber seals for 3 minutes.
Sterilizing these jars with glass lids is a little different than with metal canning ring lids and seals, but not by much.
To start, wash every part of your jar as you normally would using hot, soapy water. Leave the jars to drain upside down on a dish towel until they’re thoroughly dry. You can then transfer them to a rimmed baking sheet and put them in a pre-heated oven at 180 degrees Fahrenheit.
Bake the jars for 15 minutes. While you’re doing this, boil your fresh rubber seals for about 3 minutes before transferring them to a sterile surface.
Opening a Canning Jar With Rubber Seals
To open a canning jar with rubber seals, first, try to pull open the lid with your hands. It should not come open. Then, use a jar opener or a pair of pliers to grip the edge of your rubber seal and twist until you can hear the air release.
Before opening your jar fully, you’ll need to test the seal. To do this, make sure your jar is unclamped and pick it up by the lid. Do a little twirl and maybe try to open it with your fingers. If it stays secure, then your contents are safe.
To open the jar, you can use a jar opener like the one sold by Le Parfait. These look like bottle openers but have a long end with two pieces of metal twisted up to meet each other. With these, you’ll slip the rubber tab into the gap between the metal pieces and twist the entire thing so the tab is stretched. You’ll hear the air let out to tell you it’s open.
If you don’t have one of these, you can use a pair of pliers without much tooth, so you don’t damage the seal. Grip the tab and twist as you would have with the jar opener. This will let the air out and open the jar.
Reusing Rubber Seals From Canning Jars
You cannot reuse the rubber seals on canning jars because the shape of the rubber has been altered by the sealing process. After being used once, they will not be able to seal properly on second use.
Though you can’t reuse the rubber seals, that doesn’t mean they have to go to a landfill. Do a search for “Where can I recycle rubber nearby,” and you should come across some facilities that accept it.
Now that you know how to use canning jars with rubber seals, you can make your preserves safely and effectively. The advantages? You aren’t sacrificing a safe seal, and you get beautiful storage and less waste.