Attention! Very important science: Tapping a can of fizzy beer does... absolutely nothing Should you be faced with the horrors of a shaken can of beer and an urgent need to open it, science has solved the question of whether or not tapping the can helps reduce the fizz when it is opened. Researchers from the University of Southern Denmark carried out a randomised controlled trial of 1,000 cans of beer (PDF). The …
First, the cans are NOT tapped with a finger.
Second, though as noted, not on the side.
You use the pull ring to tap the top of the can three times (I'm a rebel/lazy and sometimes only do it twice) pulling it until there is enough tension for it to spring back with speed. This creates the resonance to dislodge the bubbles. Using your finger does not create this.
Will test again tonight under duress.
The shockwave from a tap of given wavelength only collapses bubbles of a given size. Since bubbles vary in size, several taps with varying wavelengths are required to collapse a significant proportion of bubbles from the foam back into drinkable liquid, both reducing the quantity of foam liable to be ejected, and reducing the pressure which causes said ejection. Three taps are insufficient, and the assumption in the study that one tap is as good as another is false.
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Don't mention Shepherd Neame in a conversation about good beer. Not only is theirs mostly rubbish, they took out a protected designation of Kentish ale as requiring water from an artesian well, such as they have within their Faversham brewery. And which no other east Kent brewery has, meaning that a brewery in say, Ramsgate, or Cantebury, can't describe their beer as Kentish.
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/271161/pfn-kentish-ale.pdf
(Re-posted with a " 't" included)
” I am afraid my (ahem) extensive testing over the years has confirmed what these”
No no no, absolutely NO! Nothing is confirmed yet and more testing is definitely needed. Lots of testing, every weekend, and occasionally on weekdays too, has to be done before anything can be said.
We need to test bottles and jugs too. Your never know, unless you test it, if beer (that sneaky bastard) decided to act like it was in a can, even when it’s not. All types of beer need to be tested too, and don’t forget make your sample size large enough to get statistically meaningful data.
Don’t we agree on this, huh?
> IIRC a "fizzy bottle" of pop does not fizz bubbles on the inside until you open it, shaking or not.
Beer is quantum in nature. It's not actually there or not there at all until you open it. Or rather it is both. Until you open it and collapse the probability wave (with or without tapping).
Proof of beer's probabilistic nature:
If you open a beer, you may find that you have some, yet if you check it and check it and check it again, sooner or later you will discover that the bottle-or-can is empty!
In the olden days this was regarded as witchcraft. But we are modern and know better now. It's quantum!
Main flaw I noticed is the experiment introduced too many variables. Cans should have been shaken by a carefully* designed mechanism, then precisely* tapped by a mechanical finger to produce consistent* results.
Which of course would require inviting the engineering department to participate. Which has the added advantage of ensuring the liquids used in the experiment are safely disposed of.
*Ish. Fair play to Carlsberg for their participation. Also note that the optimal way to deliver 1,000 cans of beer is in 42 slabs of 24. Thus proving that beer is the answer to life, the universe and science..
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“Cans should have been shaken by a carefully* designed mechanism, then precisely* tapped by a mechanical finger to produce consistent* results.“
That was my thought too. Not very scientific.
“ Which of course would require inviting the engineering department to participate.”
Then again, maybe they were thoughtful enough to shake the cans _really_ carefully in order to avoid excess spillage and make the engineers even happier?
“Also note that the optimal way to deliver 1,000 cans of beer is in 42 slabs of 24. Thus proving that beer is the answer to life, the universe and science..”
Wow, that’s deep! I always knew that breweries hold keys to the secret information on life, universe and stuff, but couldn’t ever quite grasp why. That is indeed the reason why beer cans come in slabs of 24, thanks!
If you look carefully, you note that 24 becomes 42 if you reverse the most and least meaningful digits. That information has to contain some secret knowledge too. Being a pastafari is so yesterday. I’m gonna convert into a beerafari.
Cheers everybody, it’s Friday again!
If you look carefully, you note that 24 becomes 42 if you reverse the most and least meaningful digits. That information has to contain some secret knowledge too.
It's a big-endian vs little-endian thing. This confuses arts students* when confronted with bottled beers. Engineers & cans are little challenge, because engineers are, after all, tool users.
*possibly why so many end up in politics. Then again one of those feckers sold a banana for over $100k. I duct taped a can of WD40, titled it 'Life Imitates Art' and just got thrown out of the gallery.
I raise your research from a questionable source like an actual doctor doing real research with a video from some guy on youtube.
https://youtu.be/K-Fc08X56R0 (Derek Muller of Veritasium)
His video was specific to fizzy drinks though, not beer. I leave it to my fellow commentards to discuss how relevant this might be :)
"Cans selected for abuse were shaken for two minutes"
There's your problem. Nothing on earth is going to help if you shake a can for 2 minutes. Tapping may help if you've dropped it, or it's been briefly agitated.
I would have said that this experiment was a waste of good beer, except that they used lager, (and Carlsberg at that), so this experiment actually slightly increased the global average beer goodness.
No. A can is as close as you can get to a mini cask and is better than anything else for keeping one serving of beer in optimum condition. Just because crap lager comes in cans doesn't mean everything in a can is rubbish. There are many fine ales and craft beers available in cans at your local proper drinking establishment that provide quality and choice when a whole cask isn't economically or logistically viable.
This is an interesting topic. I argued with my whisky-loving friends that if glass bottle can alter taste of whisky. After a lengthy search on the topic, I finally found a study which confirmed that whisky reacts with glass in a way which can be measured and can potentially alter the taste. It takes 20-30 years to have any significant effect, though, so letting Famous Grouse to rest one more year won’t make any significant change in its taste :)
What is even more interesting is that if you immerse a gold ring in distilled water (controlled one) for 20 minutes, a measurable amount of gold dissolves into the water. The researchers’ goal was to demonstrate that significant, albeit small amounts, of precious metals dissolve into sewage water and it makes economically sense to extract those traces of metal from sewage. After reading about the study, I won’t ever again dismiss anyone claiming that she/he tastes metal in a food or beverage.
"There's your problem. Nothing on earth is going to help if you shake a can for 2 minutes."
True. But it makes an excellent prank. I hope they used a paint shaker as well!
The bubbles don't appear because they are microscopic while under pressure and most of the gas is held dissolved in the liquid, on opening these bubbles expand rapidly as the pressure drops.
Divers suffer from the bends for the same reason when nitrogen bubbles form in the blood when they decompress too fast.
Divers get the bends because the solubility of a gas increases with pressure (actually partial pressure - that is the pressure of that gas alone). More gas dissolves in the blood stream under he higher pressure at depth, and then tries to suddenly form bubbles as the pressure is released when the diver surfaces,
Very similar to soft drinks, but if is the gas is dissolved there aren’t bubbles, microscopic or otherwise. It is only when the ceases to be dissolved that bubbles form.
Incedentally was the beer warm or cool for the test? The liquid temperature has a significant effect on CO2 solubility that’s why there”s no carbonated tea. (Well, not hot tea)
You still need nucleation sites. For gas to spontaneously form bubbles within the bulk liquid is actually very difficult due to energy constraints, this is why when you open a bottle of sparkling water you typically get a pop, but it doesn't usually (if it's been standing for a while) transform immediately to foam. Typically bubbles actually grow from microscopic nucleation sites, which might be microscopic bubbles in the bulk, surface irregularities of the container, turbulence and suspended particles.
Studies someplace or other have shown that bubbles will rise through blood, even against normal circulatory flow, so to avoid gas bubbles ending up in the head - which is bad - the simplest solution (or whatever the term is for things coming out of solution) is to ascend from your dive feet first, and stay that way through the decompression period.
Challenging, but wont somebody think of the children, or whatever..
icon - actually a thumbs up, inverted
> Divers suffer from the bends for the same reason when nitrogen bubbles form in the blood when they decompress too fast.
Good point! You have hit upon a cure for this syndrome!
Scuba divers need no longer hang around for long tedious hours at various unter-altitudes reading soggy newspapers or poking uselessly at short-circuited phones.
Now, via the innovative WellyGoss™ Technique, they merely burst out the surface at full speed, are rapped smartly over the head with a hammer 3 times, let out one almighty belch, and climb safely onto the boat. Huzzah!
.
EDIT: ah poo -- just belatedly saw Roger beat me to it. Perhaps the WellyKynastoGoss Technique? Or better, WellyKyn -- makes for a great advertising slogan: "make the welkin ring with the wellykyn ding!"
Agreed. The way I deal with shaken soft-drink bottles / beer cans is to open them the tiniest of cracks that allows only gas to escape. Heavily shaken bottles / cans will still force some liquid through the tiniest gap, but volume loss is minimal (you got to mind the range of spurts though!!)
I think that physics has shown that bubbles have to form on the imperfections of a surface, such as the side or base of the vessel, but also sediment otherwise you have a supersaturated solution. The formation of bubbles gives them lots of energy to move around in the liquid as they expand.
If you mean pub-style, ales, you may have a point, otherwise not really.
in 2016 there were 187 breweries with more than 1400 types of beer. The last 30 years there has been an explosion of micro-breweries, most of which of course produce very little.
I think there these days are more variety of quality beers in Denmark than in Germany
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Nope, it's not asking questions that held us back. It may not be the most important question in the world, but it's still a question and it's still an advancement of knowledge.
And if you want to get snotty about it, it's actually a good test of flow dynamics in a sealed vacuum.
This seems to me to be the most important factor, one that they did not investigate.
Pull the ring quickly, rapid loss of internal pressure and the beer will fizz out.
Pull slowly opening it a crack, wait for the internal pressure to reduce and then complete the opening and little beer will be wasted.
I thought that most kids learned this with bottles of pop.
An old-style commuter train loaded with passengers was sitting at the platform. Hot day, no aircon, so the sliding windows at the top were open.
Outside, a group of kids was kicking about an extra large can of beer (Fosters, I think, but it was many, many years ago).
Just as the train starts to move off, one of the kids picks up the can, cracks it open and puts it through a window.
The effect inside was as if a grenade had been thrown in.
To be fair, I did feel sorry for those inside, even though they were yuppies.
Re: throwing an open container; Aren't bars obliged to open canisters for you precisely because an open can makes a poor projectile (I imagine it's not as 'solid' since the liquid can now slosh about and spew out cancelling out the kinetic(?) energy you applied to it while hurtling towards your opponent)
No, that's just because of licensing laws. In general on-licence and off-licence are exclusive - either you can sell alcohol for consumption on premises or off premises, but not both. Exceptions could be made so some pubs might be allowed to sell sealed drinks, but for the most part somewhere with an on-licence would always open the drinks to make sure they had to be drunk on site and not taken away for later. They were never actually required to do so, it just made it a lot easier to show compliance. Licensing laws changed around a decade ago, so there's a lot more variation and individualised license, but places with only an on-licence will still often do this.
"Licensing laws changed around a decade ago, so there's a lot more variation and individualised license, but places with only an on-licence will still often do this."
I may be wrong, but I think the deciding factor on whether or not a site can hold both types of license is whether or not the establishment brewed or distilled its own products on-site; craft products usually see limited exposure in mainstream stores so they needed to be able to sell take-home craft directly to the consumer.
If, after each test, the scientists disposed of the contents of each open can in the least wasteful manner, I suspect that the test results became progressively more inaccurate as the testing progressed.
When a student, I played a variation on the game of chess. Each chess piece was substituted by a miniature bottle of spirits. When you took an opponent's piece, you had to drink it. This had the effect of equalising the players' ability as the game progressed. By the end of the game neither of the players knew who had won and who had lost. Nor did they care.
Ah, but the clever boffins actually weighed the cans to determine the loss of "beer" rather than measuring the volume. [One assumes they assiduously wiped/dried the outside of each can before weighing, as some (most?) of the lost liquid might well have clung to the can.]
One also wonders how damp the lab coats of said boffins were by the end of this procedure.
The researchers "reserved a few of the opened cans from the exercise for our own consumption at the end of data collection"
What they meant to say was :" We considered it vital to determine whether the quality of the contents were adversely affected by the experiment. We ensured a large enough sample size for this exercise following data collection . Bøøørp!"
As a Muscle Biologist I was aware of a group in Hawai’i who worked on the jaw closing muscle of the lobster. Just the jaw closing muscle you understand*. Leaving the meat, I mean muscle in the claws and tail available as comestibles. Nice work if you can get it.
Closest we came during my PhD was when the Chinese postgrad looking at deer velvet brought some in, sliced, for the lab postdoc when he learned he had been married for 5 years without any children. Apparently one stir fries it and it’s regarded as an aphrodisiac and general sexual tonic. Since as a mere PhD student and married with two offspring I didn’t rate any of it.
If anyone were wondering BTW there’s enough meat on a rat to make it worth eating but not on a mouse. I have never indulged, but you never know when the needs must.
The idea behind the tappings is to remove as much liquid as possible from around the soon-to-be opening so it doesn't spray. The bubbles take longer to reach the opening and would gush liquid rather than spray. I wish they'd have done more thought exercise before doing this.... Or was the intent to do as many studies as possible?!? Which is not a bad idea...
I follow an interesting YouTube channel that's an offshoot of an equally interesting website called Today I Found Out, and they did some research into this awhile back that came to the same sad conclusion.
http://www.todayifoundout.com/index.php/2017/11/tapping-soda-can-actually-anything/
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