# Why does whiskey foam more than other spirits in a mixed drink?
**URL:** https://boards.straightdope.com/t/why-does-whiskey-foam-more-than-other-spirits-in-a-mixed-drink/565806
**Category:** Factual Questions
**Created:** [December 30, 2010, 6:47am UTC](https://boards.straightdope.com/t/why-does-whiskey-foam-more-than-other-spirits-in-a-mixed-drink/565806 "2010-12-30T06:47:16Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@GameHat](https://boards.straightdope.com/u/GameHat)
#### Post date: [December 30, 2010, 6:47am UTC](https://boards.straightdope.com/t/why-does-whiskey-foam-more-than-other-spirits-in-a-mixed-drink/565806/1 "2010-12-30T06:47:16Z")
Here’s a question for the ages, no doubt. 😉
I’ve noticed - when you’re making a mixed drink, whiskey foams more (and the foam lasts longer) than any other spirit I’ve used.
Example:
Take one shot each of:
Rum
Vodka
Gin
Whiskey
Pour one shot of each in a pint glass.
Then add 1 can of cola (I know, this doesn’t really go with the gin, but humor me. You can substitute a can or equivalent of tonic, but then it wouldn’t be scientific.)
The whiskey drink will foam much more than the others and the foam seems to be “stickier.” Why?
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### Author:  [@EvilTOJ](https://boards.straightdope.com/u/EvilTOJ)
#### Post date: [December 30, 2010, 9:04am UTC](https://boards.straightdope.com/t/why-does-whiskey-foam-more-than-other-spirits-in-a-mixed-drink/565806/2 "2010-12-30T09:04:33Z")
It’s not actually the whiskey, but the cola that’s foaming. There must be more nucleation sites in the whiskey than in the other spirits, but I couldn’t tell you why. I’m at work so I can’t test this (the bastards) so you’ll just have to take my word on it.
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### Author:  [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)
#### Post date: [December 30, 2010, 12:35pm UTC](https://boards.straightdope.com/t/why-does-whiskey-foam-more-than-other-spirits-in-a-mixed-drink/565806/3 "2010-12-30T12:35:44Z")
Aren’t the other spirits you are using clear? Could you do a control where you use a dark rum?
It is (if a real effect – I refuse to waste any of my whiskies in a “mix with cola” situation) most likely due to the additional impurities in a dark liquor giving more structure to the foam.
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### Author:  [@LeidenFrost](https://boards.straightdope.com/u/LeidenFrost)
#### Post date: [December 30, 2010, 5:37pm UTC](https://boards.straightdope.com/t/why-does-whiskey-foam-more-than-other-spirits-in-a-mixed-drink/565806/4 "2010-12-30T17:37:53Z")
Chemical Engineer checking in here:
```
I too have noticed the same phenomenon when it comes to mixed drinks. Foaming is an issue that effects full scale chemical production as well. The same dynamics happen in your kitchen as they do in a chemical plant.
Foaming happens when there is a mixture of solid particles suspended in the vapor phase. There are chemical streams which are known to be common foamers, such as amines (nitrogen containing compounds).
Whiskey probably either has more solids in it than the other spirits, or a type of solid that foams when mixed with cola. My best guess would be an organic base that comes from the barrel in which it is aged. Whiskey always has the "woodiest" flavor of the aforementioned spirits, which most likely means that it has the most of these compounds.
```
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### Author:  [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)
#### Post date: [December 30, 2010, 6:00pm UTC](https://boards.straightdope.com/t/why-does-whiskey-foam-more-than-other-spirits-in-a-mixed-drink/565806/5 "2010-12-30T18:00:41Z")
> [@LeidenFrost](#):
>
> Chemical Engineer checking in here:
>
> ```
> I too have noticed the same phenomenon when it comes to mixed drinks. Foaming is an issue that effects full scale chemical production as well. The same dynamics happen in your kitchen as they do in a chemical plant.
>
> Foaming happens when there is a mixture of solid particles suspended in the vapor phase. There are chemical streams which are known to be common foamers, such as amines (nitrogen containing compounds).
>
> Whiskey probably either has more solids in it than the other spirits, or a type of solid that foams when mixed with cola. My best guess would be an organic base that comes from the barrel in which it is aged. Whiskey always has the "woodiest" flavor of the aforementioned spirits, which most likely means that it has the most of these compounds.
>
> ```
Why not try a dark rum? Dark rum is aged in barrels.
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### Author:  [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)
#### Post date: [December 30, 2010, 7:50pm UTC](https://boards.straightdope.com/t/why-does-whiskey-foam-more-than-other-spirits-in-a-mixed-drink/565806/6 "2010-12-30T19:50:24Z")
What kind of whisk(e)y? What about tequila and cognac?
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### Author:  [@GameHat](https://boards.straightdope.com/u/GameHat)
#### Post date: [December 31, 2010, 9:36am UTC](https://boards.straightdope.com/t/why-does-whiskey-foam-more-than-other-spirits-in-a-mixed-drink/565806/7 "2010-12-31T09:36:04Z")
> [@LeidenFrost](#):
>
> Chemical Engineer checking in here:
Heh, I’m a ChemE too! Respect!
> [@LeidenFrost](#):
>
> Whiskey probably either has more solids in it than the other spirits, or a type of solid that foams when mixed with cola. My best guess would be an organic base that comes from the barrel in which it is aged. Whiskey always has the “woodiest” flavor of the aforementioned spirits, which most likely means that it has the most of these compounds.
I think you’re probably right. I was hoping for someone to have a definitive answer, but it seems like this one is a paper waiting to be written.
😉