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Author Topic: Why does ice make fizzy drinks bubble over?  (Read 1101 times)

Offline thedoc

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Why does ice make fizzy drinks bubble over?
« on: 23/01/2016 04:50:03 »
Tim Coleman asked the Naked Scientists:
   I've been looking for an answer to a science question, and I don't know if it has been asked before. First, there is this question: "Why does ice make fizzy drinks bubble over?" (

But I have noticed that plain soda water, or club soda, does not bubble over in the same way as soda with flavour added. Also, I am fond of adding my own flavours to club soda, and if I add the flavour to ice before pouring the liquid, it will be super fizzy, but if I add it after it will be fine. So is there something in the flavouring that causes it to bubble over?
What do you think?
« Last Edit: 23/01/2016 04:50:03 by _system »


Offline chiralSPO

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Re: Why does ice make fizzy drinks bubble over?
« Reply #1 on: 03/02/2016 05:04:10 »
Very observant!

I think there are two things going on here:

1) The ice increases the rate of bubble formation by giving the bubbles more surface area to form on (you can do the same thing with a sugar cube, some Mentos or even just by scratching the glass)

2) The flavoring must somehow make the bubbles last longer. A similar effect can be seen when making pasta in a pot of boiling water--just a pot of water boiling away with the lid on won't boil over, but once there is pasta in there, starch dissolves in the water, making the bubbles more sturdy. Keeping a lid on a boiling pot of pasta water will lead it to boil over. I believe the reason that this doesn't happen with the lid off is that water evaporates from the surface of the bubbles, making them weaker. When the lid is on, the air over the bubbles quickly becomes saturated with water, and prevents this mechanism for bubble collapse.

So the ice makes the bubbles form faster, and the flavoring makes the bubbles last longer, together leading to a mess!

Offline chris

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Re: Why does ice make fizzy drinks bubble over?
« Reply #2 on: 03/02/2016 08:16:15 »
I think there must be something in the flavouring and colouring that affects the surface tension of the water; this has the effect of stabilising bubble films, making the bubbles easier to form in the first place and last longer, as suggested above.

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Re: Why does ice make fizzy drinks bubble over?
« Reply #2 on: 03/02/2016 08:16:15 »


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