# Why does tapping on the top of a shaken soda can keep it from exploding when opened?
**URL:** https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156
**Category:** Factual Questions
**Created:** [August 3, 2020, 2:03pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156 "2020-08-03T14:03:36Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@obbn](https://boards.straightdope.com/u/obbn)
#### Post date: [August 3, 2020, 2:03pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/1 "2020-08-03T14:03:36Z")
Question in title. Drop a can of soda and open it and you’re showered with a fizzy explosion . Tap the top of the can a few times and you disarm the fizzyness. Why?
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### Author:  [@tofor](https://boards.straightdope.com/u/tofor)
#### Post date: [August 3, 2020, 2:05pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/2 "2020-08-03T14:05:06Z")
It doesn’t. Except for the fact that it forces you to wait a little bit before opening it.
> **[Tapping a Soda Can](https://www.snopes.com/fact-check/on-tap/)**
>
> Will tapping the side of a soda can keep its contents from foaming over upon opening?
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### Author:  [@superwombat](https://boards.straightdope.com/u/superwombat)
#### Post date: [August 3, 2020, 7:18pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/3 "2020-08-03T19:18:07Z")
I’ve found if I turn the can end-over-end gently a few times before opening it can calm the spew a bit. This could just be placebo effect, YMMV.
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### Author:  [@TriPolar](https://boards.straightdope.com/u/TriPolar)
#### Post date: [August 3, 2020, 7:19pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/4 "2020-08-03T19:19:19Z")
It does work if you tap it several hundred of times
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### Author:  [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)
#### Post date: [August 3, 2020, 7:44pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/5 "2020-08-03T19:44:07Z")
I always thought the tapping broke up the bubbles or something. I’ve seen it work and I’ve seen it not work. YMMV
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### Author:  [@AlsoNamedBort](https://boards.straightdope.com/u/AlsoNamedBort)
#### Post date: [August 3, 2020, 7:50pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/6 "2020-08-03T19:50:49Z")
> [@Beckdawrek](#):
>
> I’ve seen it work and I’ve seen it not work.
The problem with saying “I’ve seen it work” is that, yes, you’ve seen cans that were tapped and then there was no spray. But how can you if it was going to spray if it hadn’t been tapped?
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### Author:  [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)
#### Post date: [August 3, 2020, 7:59pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/7 "2020-08-03T19:59:21Z")
I saw it get shook up first, and assumed it would spew if opened.
All things be equal.
Son-of-a-wrek has actually spent a good bit of time experimenting with this. With beer cans. We think it’s a ruse to get to drink more beer in the name of science.
Hmmm? I may have to revive this question. We need an activity for today
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### Author:  [@The\_Librarian](https://boards.straightdope.com/u/The_Librarian)
#### Post date: [August 3, 2020, 9:38pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/8 "2020-08-03T21:38:50Z")
It doesn’t do anything:
> **[Attention! Very important science: Tapping a can of fizzy beer does......](https://www.theregister.com/2019/12/13/science_solves_shaken_beer_conundrum/)**
>
> But Danish boffins tapped cans on the side, not the top – we demand a retrial
However it is a very useful tool to “measure” superstition or confirmation bias.
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### Author:  [@TriPolar](https://boards.straightdope.com/u/TriPolar)
#### Post date: [August 3, 2020, 9:46pm UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/9 "2020-08-03T21:46:31Z")
[If Homer had just tapped on the beer can maybe everything would have been fine.](https://www.youtube.com/watch?v=q1mxGu9fYaQ)
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### Author:  [@MonkeysBrother](https://boards.straightdope.com/u/MonkeysBrother)
#### Post date: [August 4, 2020, 12:15am UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/10 "2020-08-04T00:15:37Z")
Here is a relevant video from Veritasium. He uses a plastic bottle instead of a can, but gets a clear result. The whole video is interesting, but the relevant part starts around 7:50.
[ ](https://www.youtube.com/watch?v=K-Fc08X56R0)
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### Author:  [@MikeS](https://boards.straightdope.com/u/MikeS)
#### Post date: [August 4, 2020, 11:29am UTC](https://boards.straightdope.com/t/why-does-tapping-on-the-top-of-a-shaken-soda-can-keep-it-from-exploding-when-opened/917156/11 "2020-08-04T11:29:01Z")
[The Master speaks.](https://www.straightdope.com/columns/read/1034/will-tapping-a-pop-can-keep-the-carbonation-from-exploding-on-opening/)