There is enough food at home to be at ease, and canned food with a long shelf life is the first choice for hoarding food. However, what if you can't unscrew these bottles and cans!
The reason why the newly purchased cans are difficult to unscrew is two reasons: one is that the internal air pressure of the can is low, and the lid is "sucked"; the other is that the machine on the assembly line is stronger than the force and tightens.
In response to these two points, we have summarized some good operation methods, which should help you who are jumping around the can. The significance of this push also includes throwing bricks and stones to see what other good ways people will share in the comments.
Pry it!
Have you noticed that the edge of each can lid has a small indentation? Take out your spoon, scissors, and fruit knife, reach through the edge of the recess into the crevice of the lid and bottle, and with a little force, pry it!
Picture 丨 Li Xiaokui
Soon you will hear a soft "boo" sound from the metal lid: the air pressure inside and outside the jar is balanced by the small gap that has been pried out, and the sucked metal lid looks like I myself who is no longer trying to close my abdomen, and my stomach is slacking out.
Congratulations on prying open! Easily unscrew and eat!
Here I would like to remind everyone that the pry can is still a little loss to the tip of the knife. The tip of the scissors that had followed me for years had been bent a little bit because it had pried too many cans. Try to pry it with bargains.
Don't pry it with a ceramic knife, you should know how I came to this conclusion.
In addition, a colleague said that she always used her teeth to pry. Not only did we not recommend it, but we even criticized our colleague's approach.
Knock it on!
There are no cheap scissors and spoons at home to pry, then you can take the can, put the edge of the bottle cap towards the hard (recommended cutting board, not recommended to bump the wall) place a few times, so that the metal lid produces a little deformation, so that the sealing environment inside the can is destroyed, the air pressure is balanced, so that it is easy to unscrew.
Knocking on it several times is useless? Then you change the angle and knock a few more times.
Picture 丨 Li Xiaokui
There are also points to pay attention to in this method. I personally think it's more suitable for cans that are almost only up and down the general thickness. If the jar has a waist, there is a risk of breaking the waist. I was caught in a dilemma when I experienced this scene: the food in the broken jar, the food that I would be hungry if I didn't eat it, the glass ballast if I ate it...
Also, don't push too hard, if the lid is too deformed, you can't tighten it very tightly after use.
Shoot it!
I see this method used by many elders. Pick up the can, point the bottom of the can against yourself, and then slap the can's ass violently with the palm of your other hand a few times before unscrewing it.
Picture 丨 Li Xiaokui
I'm not particularly sure of the principles. A study of "crushing" the bottom of a beer bottle said that a violent slap on the mouth of the bottle caused bubbles to form inside the bottle; these bubbles disappeared immediately after the beating stopped, generating no small amount of energy, thus breaking through the bottom of the bottle [1]. The results of this study may also explain the canning. Everyone is welcome to give us a little guidance in the comment area~
The colleague mentioned above who used his teeth to pry the lid of the can told me that slapping the lid of the can is also very useful, more useful than patting the bottom of the can.
Because I have seen elders open cans like this, and because I trust colleagues, I want to be useful for patting cans. However, I only tried it once, and I didn't succeed, because it was really painful to slap the bottom of the glass bottle with my hand, and it was difficult to keep slapping it several times.
Soak it!
In response to the unscrewing caused by air pressure, the above methods are a bit violent, let's talk about a little mild.
Many canned foods are hot processed, and when the food is still hot, the machine screws on the lid. When the food gradually becomes room temperature, the air in the tank shrinks and the air pressure becomes low, and the lid is difficult to be unscrewed.
Then we'll make the air inside hot! The hot air expands and unscrews! Soak the can in hot water, or turn the can upside down and soak only the head of the can, and it will be easy to unscrew after a while.
Picture 丨 Li Xiaokui
It's a bit troublesome to use hot water, and it's okay to take a hair dryer to blow hot air, but you must not use the microwave oven to heat it, and don't forget that the lid of the can is made of metal.
Take a different approach and screw it!
The above methods are all countermeasures for the imbalance of air pressure inside and outside the can. For the situation that the lid of the can is too tight and the strength of ourselves is too small, we can also use our small brains and use the knowledge of the primary school nature class to solve it.
Find ways to increase friction. When twisting the can, you can pad a paper towel between the hand and the can (the effect of the pro-test facial tissue is better than the dry towel), and you will find that the friction will help you a lot in the process of unscrewing!
Picture 丨 Li Xiaokui
In addition to paper towels, you can also pad a wet towel, plastic wrap, put a leather band around the waist of the lid of the can, or wear rubber gloves for washing dishes. To exaggerate a little more, find a relative or friend with a particularly rough palm to try, it is not impossible...
The method of increasing friction and unscrewing is also suitable for this kind of bottle cap 丨 Li Xiaokui
The world's cans, in addition to metal lid glass bottles, there are also tinplate cans. Tinplate cans are usually equipped with can openers or pull rings, so don't worry too much. But if you really have a pull ring pulling off, pray that there are chisels and hammers in the house.
bibliography
[1] Daily J, Pendlebury J, Langley K, et al. Catastrophic cracking courtesy of quiescent cavitation[J]. Physics of Fluids, 2014, 26(9): 091107.
Author: Li Xiaokui
Edit: luna
Knowledge Aid: Owl
An AI
You ask me how to open a beer bottle without a screwdriver? Don't drink it if you can't open it.
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