Introduction: Open a Stuck Jar With a Knife

Picture of Open a Stuck Jar With a Knife

Jars can be troublesome little jerks. They're stuck tight and you're stuck trying to pry them open with your hands.

To make them easier to open all you need is a regular table knife. No fancy tool, no extra junk to fill up your kitchen, just a few hits with a knife.

For those who want TWO ways to open a jar with a knife, here's part 2.

Step 1: A Few Whacks

Picture of A Few Whacks

To loosen the jar is just a matter of three or four hits on the lid with a knife so you get some dents. These dents loosen the seal and make the jar easier to open.

To be more precise, do this:

  1. Hold the back of the knife against the jar at a 45 degree angle
  2. Pull it back a bit
  3. Whack the back of the knife hard against the corner of the lid so it leaves a small dent
  4. Repeat 2-3 times around the lid
  5. Open

Step 2: What Success Looks Like

Picture of What Success Looks Like

In case you're wondering just how big of a dent is appropriate, here's a close up shot. You should be able to catch your fingernail in it.

Jars can take a pretty strong hit. I've never had a jar break while doing this and I've done it hundreds of times. Check out the video in the intro to see how much abuse a salsa jar can take.


fatimahtravers212 (author)2017-11-09

Nice Way.

PrincessPug10 (author)2016-10-16

Why bother with a jar opener? lol.

jakecreates (author)2016-06-26

Does this technique work on plastic jars and lids too?

cuyler1 (author)2016-05-12

I was taught this way over 50 years ago by my grandmother. back then men were at work while women stayed home to open jars.

True story... my grandmoter was a professional jar opener. She was hired by IBM in the 30's. back then, IBM produced peanuts for elephants who were the country's main form of public transportation. The company would import hundreds of peanut butter jars from Amsterdam and my grandmother would spend all day opening the jars and handing them off to the Peanut Assembler, who would reassemble the peanuts for packaging. In 1934, my grandmother was invited to England to meet the queen, as she (my grandmother) had opened her 5 millionth jar. In 1940, my grandmother lost her job as the country abandonded elephant transportation in favor of porcupines... and, as we all know, porkupines don't like peanuts.

I would like to hang out with you. More stories please!

how does one reassemble peanuts from peanut butter?

Pollin8 (author)Cat00x2016-06-05

lol, sounds more like empty peanut butter jars?

This seems a little far fetched but because I didn't know your grandmother I'm going to take your word for it ;)

ShilpaAtwaal (author)2016-05-27

Best of the Best

TJLee089 (author)2016-05-17

Despite the many alternatives presented, whacking the jar with a knife, as shown, is by far the simplest/fastest. I have been doing this for 50 years with never a problem.

ggallen103 (author)2016-05-03

What works even better , using the same knife, slide the tip end between the glass and the lid, and turn the knife slightly, this will break the vacuum seal, then it's a breeze to open from there. Doesn't dent the lid either.

DiegoZ1 (author)ggallen1032016-05-16

You're absolutely right! Hitting the lid with the knife can crack or dent the glass border, so pieces of glass can enter the food... Breaking the seal or loosen the lid from dried food is easily accomplished the way you explained. As an added bonus, the same method (knife between lid and glass) works for oppening beer or soda bottles without the risk of breaking something.

crackedpiston (author)ggallen1032016-05-13

I have been using your method for years but with a vintage 60s beer can opener to pry with. I never have broken a jar top. Sometimes rusted fruit jar bands are so hard to loosen the bands are unuseable after getting them off.

Katzsta (author)ggallen1032016-05-12

This is the way I always open new jarred products. The goal is to pop the seal, not rip the top off. I will admit that sometimes I am a bit worried about tiny pieces of glass breaking off, but so far, no cut lips. Oh, and definitely use a metal knife, preferably stainless steel or some other hardness.

I haven't tried that in a long time and when I did it was with a pretty flimsy knife. So... that must've been a college dorm. As I recall, the knife end got twisted and the jar didn't open. Probably works better with a "real" knife.

so maybe try the spoon, the distance between hand and top of the spoon is less

most butter knives are strong enough. You really need to get the point up inside the lid. You basically are lifting the lid just so slightly to allow air in. probabally the blunter the point, the better - it will give more area, whereas a pointed end knife will tend to twist more.

OK, I went back to the market and got two more jars to try that out. One worked great. The other not so much. So maybe just keep both in mind.

Thanks for the tip, here are the results.

yes! this is what i do with a teaspoon: little force needed, fast and no damage to lid nor jar. I prefer the spoon as it has no cutting edge

neversleep49 (author)2016-05-15


SamMechatron (author)2016-05-14

Use a lighter or any source of heat to heat up the lid slightly. The heat in the lid will cause it to expand loosening the lids grip on the jar.

gustoolmaker (author)2016-05-13

Turning the jar upside down and firmly hitting the lid squarely on a solid surface breaks the seal with damaging the lid.

Bauke (author)2016-05-13

Nice way! Wouldn't work for left-handed people though. :)

Wobbledagger (author)2016-05-13


Simply use a piece of that anti-slip mesh you put in cutlery draws, cupboards etc.

Another way. Most people grip the lid using thumb, forefinger and middle finger as the primary fingers. Well that is wrong as the strongest fingers are the middle, third and little fingers. You can get most lids off that way. Your thumb and index fingers are really for dexterity not strength.

RobP37 (author)2016-05-12

Got Hot Water? Run the tap until it's hot and then turn the jar on its side and hold the lid under the water for about 10 seconds...take a tea towel/dish cloth and remove the lid. The heat breaks the seal. Simple and no dents!

A Potts (author)RobP372016-05-13

There are several benefits to this method. First, you don't destroy the seals on your jars after repeated openings. Second, if the lid is stuck because there's something sticky like jam or honey on the threads, the hot water helps loosen up the crusties.

ronjohnstone (author)2016-05-12

Go to a decently stocked kitchen gadget store. Surely they will have a jar opener that mounts under a kitchen cabinet. It will have a V shaped slot with a smooth metal side and a rough metal side. Now, just insert a jar with a tight cap into the V and turn the jar. The cap will be captured in the V and the jar will turn, thereby opening the jar. Works like a charm, takes seconds and you always have the tool, out of sight, ready to go and it should only cost a couple of dollars.

hazlett (author)2016-05-12

I am 74 years old ans have been using this trick for over 65 years. It does work grest but I think it helps if the blows are struck at the angle needed to s\put a light twist on the lid.

CaroE1 (author)2016-05-12

I usually try opening with rubber gloves and if that hurts the wrists too much its the old fashioned can opener with the spikey bit to pierce the top and release the vacuum. Doesn't always help if it's home made jam and they got it on the thread though....

Microbe (author)2016-05-12

If you don't have a knife handy, just whack the edge of the lid 4 times on something solid, rotating it 90 degrees each time.

PhilS43 (author)2016-05-12

Chain wrench works for me. Failing that, oil filter pliers, or WD 40.

Another one that pees me off are the caps on Tetrapak milk cartons. With some of them, you can tear the carton apart before the cap comes off. I contacted Tetrapak and their suggestion was tighten it first, then unscrew. Does work. A bit like tightening a stuck woodscrew before you knacker the head trying to unscrew it.

The jam jars can be a challenge because of the sheer area of the seal. A knife blade under the lip usually breaks the seal without the dents.

When I first read this, I had visions of a knife being plunged through the cap and Mole grips on the knife.

Anthony. (author)2016-05-12

Why not bang the lid against a wooden table or something similar, a few times and the lid comes off quite easily. it works for me all the time... minus a knife or a spoon

SusanH75 (author)2016-05-12

Done it for years use the handle instead

JUANKERR (author)2016-05-12

One prises things open; one pries into things that do not concern one.

DanielW140 (author)2016-05-12

i cant believe you guys are using a knife ...

This works 100% of the time on new jars!!!

For used jars just run them under hot water upside down to get the water into the lip.

All you need to do is turn the jar over (upside down) hold it in one hand and smack the bottom hard with the palm of your other hand.

If you smack it hard enough it will make a popping sound and that is the seal letting go!!

PS: If you're afraid the jar will break or crack (its highly unlikely) just cover the bottom with a rag or dish towel!

GeorgeG37 (author)2016-05-12

Turn jar upside down smack on bottom with heel of hand

waddoyouwant (author)GeorgeG372016-05-12

That's how you get catsup out of a bottle.

Helentalking (author)2016-05-12

take an old bottle opener (the ones our parents used to call a "church key" and use the rounded end (NOT the pointy one) and use it like you were removing a bottle cap just enough to break the seal and PRESTO!

User1 (author)2016-05-12

Have you tried to hit the jar without the lid? I imagine there would be someone out there that would have done this accidentally.

Great idea though!

billipo (author)2016-05-12

A yarn so nice you gotta post it twice?

skiwolf9 (author)2016-05-12

A meat cleaver will break it. Ever try an electric knife instead of a regular knife? Don't use a chainsaw, it'll break for sure.

Pedro Zapata (author)2016-05-12

HooRay !

bibbster (author)2016-05-12

It doesn't always work, but sometimes if you try to tighten the lid further you can then remove the lid. Just because it won't loosen enough to break free doesn't mean it won't tighten a little and break free. You can do the same with stuck bolts/nuts. Again, sometimes it works, sometimes it doesn't. Running hot water over the lid on a jelly jar or jars with other sticky contents will also sometimes loosen them. Save the knife for spreading the jelly. ;)

mrstan (author)2016-05-12

Take jar

Smash it on the floor with as much force as possible

pickup broken jar pieces

Eat contents now on floor

clean up mess on floor with mop before mom sees it

all done!

metroscoots (author)2016-05-12

I've used a similar method for years and have never had a problem with
broken glass. In my method I hit the edge of the lid on an angle that
not only breaks the seal but also starts the lid turning in the lid in a
counter-clockwise direction. It's the same principle as toe nailing instead of driving the nail in at a 90 degree angle. Works great!

S AG (author)2016-05-12

If you thought there was a *possibility* of broken glass shards, why would you only wear *one* Kelvar Oven Glove? (I have a pair!) Why not two?

prfromdover (author)2016-05-12

3. Pick out shards of broken glass.

4. Hope you got them all.

5. Make Jelly sandwich

6. Cut tongue on class you missed.

osoriocj (author)2016-05-12

Please, do not teach how to open a jar. That´s why the women need us :)

pam.vanengelshoven (author)2016-05-12

I open them with the round side of a teaspoon: position the "point" under rim with convex side against the jar for lever. Just a little bit of pushing against the jarglass with the spoon handle, and air sucks in the botle and lid opens easily.

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Bio: I like to make things for the internets. I also sell a pretty cool calendar at You'll like it.
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