If you have ever opened a jar of preserves, you know that popping sound it makes. But did you ever stop to wonder why the jars make that noise?
In this blog post, we will explore the science behind jar popping and tell you whether or not all jars should pop when they are opened.
Should All Jars Pop When Opened?
Not all canned jars make a loud popping sound when they are opened, some make a hissing sound, and others may not have much sound at all. Special lids have been created to emphasize the popping sound that is associated with jars.
Why Do Jars Pop?
When jars are being manufactured, they are placed in a chamber where the air is removed. This helps to create a vacuum inside the jar.
Once the jars are sealed, they are placed in a hot water bath. As the jars cool, the lids suck down tight to create an airtight seal.
The popping sound that you hear when you open a jar is the sound of the vacuum being released.
The reason all jars go through this process is that it helps to preserve the food inside.
If you notice your jar is not popping or making any sound when you open it there is a chance the food inside has gone bad.
Are the Contents Still Good If the Jar Doesn’t Pop?
Since not all jars will make a loud popping sound when they are opened, you might be wondering if the food inside is still good.
The answer to this question will vary from jar to jar. If the jar was properly sealed, then the food will still be safe to eat even if it doesn’t make a popping sound.
However, if you are unsure whether or not the jar was properly sealed, it is best to err on the side of caution and throw it out.
You can go through a smell test to determine whether or not the contents inside the jar are still good to eat or you can look for visible signs of spoilage.
If the food inside the jar has an off odor or if it is discolored, then it is best to throw it away.
People can become exposed to botulism if they eat contents in a jar that has not been properly sealed and handled.
Botulism is caused when a specific kind of bacteria enters your body. The bacteria starts to attack your nervous system and can cause muscle paralysis or even death.
Any food that is suspected of containing bacteria that could lead to botulism should be disposed of properly.
Why Do Some Jars Not Pop?
The reason not all jars pop equally the same is that the vacuum seal is not always perfect.
If there is a small hole in the lid, the jar will not make a popping sound when it is opened because the air will be able to escape through that hole.
A jar may also not pop if it was not properly cooled before being opened. If the jar is opened while still warm, you won’t get as much pressure inside the jar which causes it to pop.
Can Home Canned Jars Lose Their Seal?
There are several reasons why a jar may have lost its seal over time. It’s important to understand each reason so you can avoid one of your jars becoming toxic and making you or your family sick.
When you are in the process of canning your jars it’s important to not let any food or liquid get between the lid and the rim of the jar.
If this happens, it’s called siphoning and it can cause your jars to lose their seal over time.
What happens is the lid cannot properly seal because there is a bit of food or liquid that is resting between the lid and jar, causing a little bit of distance between the two.
Over time the air can enter and exit your jar causing the pressure inside to dissipate over time and ruining your seal.
Bad Storage Conditions
After you are done canning and have put your jars in the hot water bath, you should test your jars to make sure they are properly sealed.
Unscrew the ring part of the lid and if you can pick up the jar by the lid without the ring attached, you know there is enough pressure.
Go ahead and leave the rings off the jars and clean the outside all around to get rid of any potential mold that may grow on your jar.
When you are storing your jars you never want to stack them more than two jars at a time.
This will help them keep their seal and you can even put a piece of cardboard or something thin in between the jars so it doesn’t create too much pressure on the lid.
Keep your jars between temps of 50 and 70 degrees and make sure they aren’t in direct sunlight or places where it is very damp.
Frequently Asked Questions About Should All Jars Pop When Opened
How soon should lids pop after canning?
You should let your jars sit for 12-24 hours after giving them a hot water bath before your lids will make a popping sound when they are opened.
What is a false seal in canning?
A false seal is when the lid appears to be sealed but after further inspection, you realize that it is not. This can happen if there is food or liquid on the rim of the jar when you are screwing on the lid. It can also happen if your jars are not at equal pressure when they are being processed in a hot water bath.
How do you know if your jars have sealed?
You can test your jars to make sure they have been sealed by unscrewing the ring part of the lid and trying to pick up the jar by the lid. If you can do this without the ring attached, then you know your jars have been sealed.
Opening Jars With a Pop
Although not all jars will make a loud popping noise they should always be properly sealed and prevent any air from entering or exiting the jar while storing.
You never want to risk eating the contents of a jar that has not been properly sealed but if you follow the advice in this article you should never have to worry about it.
Daniel Iseli (Head Chef)
Hi, my name is Daniel and I am passionate about cooking. I have been cooking for the past 20 years and am happy to share my best recipes and cooking-related knowledge with you.