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Ice Cubes and Carbonated Drinks

RSLancastr

www.StopSylvia.com
RSLancastr
Joined
Sep 7, 2001
Messages
17,135
Location
Salem, Oregon
I've noticed that if you pour a room-temperature can of, say, Pepsi into a glass with very cold ice (so cold and "dry" that it will stick to your damp fingers), it foams up waaaay more than if you had simply poured it into an empty glass. In fact, the Pepsi will be nearly flat. Is this because of the difference in temps between the beverage and the ice? (There isn't near as much foam when the Pepsi has been refrigerated first.)

I've further noticed that if you put that cold ice into a glass, then run a little water over it, pour out the water, and THEN pour in the room-temp Pepsi, it doesn't foam up near as much. This might support the "temp difference" theory, but it doesn't seem as though the difference between the temp of the ice before and after adding water would be that great.

Thoughts?
 
<WAG>My WAG would be that it is something similar to what happens with supercooled water. Supercooled water is below freezing but not frozen, because the crystaline structure need a 'disturbance' to start.
In the same way carbonated drinks have an excess of CO2, but doesn't explode into bubbles because a disturbance is needed for the bubbles to escape. The 'dry' ice cubes are probably more of a disturbance than the water surface of wet ice cubes.
</WAG>
 
A very simplified view. The "unwashed" ice has a very large number of tiny, tiny crystals sticking out from the surface. The CO2 that is in disolved in the cola begins to form tiny bubbles when it hits these crystals. "Washing" the ice, make the surface relatively smooth which reduces the number of places that bubbles can form. Which, of course, is what bjornart said.

The foam also forms more prodigiously when the cola is poured over ice cream (or for that matter nettles).

You could test the theory by looking at "washed" and "unwashed" ice cubes under a strong microscope.
 
Wow someone else has this ice/soda problem too? I'm not alone!

At my previous house we had a well. Ice made from this water always made sodas flat, whether or not the soda was cold. Using bottled or filtered well-water to make ice-cubes would eliminate the problem. I assumed it was either our water softener, or perhaps a trace amount of some chemical in the water.
 
Both mechanical and chemical impetus will make carbonated water give up carbon dioxide. And of course, you get sort of an avalanche effect as something makes it foam up, this creates a physical disturbance, which creates more foam, etc....

Back technical college, we had a prank: Sometimes it was possible to lure somebody into putting sugar into his cola, heheh. Cola always came in bottles back then, so when we could talk somebody into pouring a spoonful of sugar down a full bottle (we told them it would taste like beer :rolleyes: ), the result would be a nice brown geyser :D , foam all over the place, and a nearly empty bottle.

BTW: Cola over ice-cream???? Yuck! :eek:

Hans
 
That's why, when you make root beer floats, you always put the root beer in first (and don't fill it up) and then the ice cream.
 
Dropping some peanuts in a bottle of Pepsi will make the Pepsi fizz up a little, too. As for why you would do this, you have to be Southern to understand. :D

I always wondered why my sodas taste flat when I pour it in a glass with ice. This is part of the reason I like to drink it straight from a can. Reading this, I understand I probably need to have a little of the soda in the glass before adding the ice, to "wash" it, then add in the rest of the soda. Right?
 
tygirwulf said:
Dropping some peanuts in a bottle of Pepsi will make the Pepsi fizz up a little, too. As for why you would do this, you have to be Southern to understand. :D

I always wondered why my sodas taste flat when I pour it in a glass with ice. This is part of the reason I like to drink it straight from a can. Reading this, I understand I probably need to have a little of the soda in the glass before adding the ice, to "wash" it, then add in the rest of the soda. Right?
Click to expand...
Yup.
 
I always run my Ice cubes under water befor I pour my Coke over them. I also prefer my Coke to be slightly de-carbonated.

I remember when I was young and we would run out of Coke, but there would still be some of my moms diet Coke left, I would just load it up with sugar and it would taste pretty much like normal Coke albeit somewhat flattened.
 
Would be a pretty simple experiment to do. Either measure the
foam height (simple) or measure the released CO2 over time between ice and no ice. Food people do this (the second test) already with things like baking powders etc.

I would certainly agree that it sounds like some of the reason is due to a surface area thing (the "rough" ice cubes). So if you really want to add your ice prior to your coke then a bigger ice cube would be better than a few smaller ones ;-)

One thing i have noticed is that of the two leading brands of cola one of them definitely holds onto it's CO2 better. This is really easy to test ;-)

AX
 
One thing i have noticed is that of the two leading brands of cola one of them definitely holds onto it's CO2 better. This is really easy to test ;-)
Click to expand...

ooh! - Which one ,which one!:cool: I *much* prefer my cola to be semi-carbonated to the horrid fizzy stuff straight out of a can.
 
It works the other way too.....cold coke into warm glasses or plastic cups.....no sooner do you start pouring and the foam is over the edge.
 
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