Something I have seen many people do - and I’ll be damned, it does seem to work.
After pouring soda over ice in a glass, in order to quickly make the foam go down so you can pour some more to fill the glass, I’ve seen people stick a finger into the foam. Unbelievably, the foam is gone much more quickly than if left to fizzle away on its own. WHY?
Oil dissipates foam.
They pop the damn bubbles with their finger.
I agree with mealworm. A swizzle stick will do the job just as well.
On a related topic; what’s the deal with shaking salt onto the head of a glass of beer? Is that supposed to disipate the foam?
Handy is right. I’ve never done it with soda, but on beer it works great. Rub your finger along the side of your nose, and touch it to the foam. The foam will decrease significantly.
“Penises don’t belong in the mouth, girls and boys. You’ve got the wrong hole there. Just like you wouldn’t shove pizza up your nose.”
-From the Brother Jed flyer-
um… gross.
Ursa, the salt into the glass of beer is actually to get more head… I s’pose to some desirable… I know I enjoy a beer better when it has a thick head than if it fizzles to nothing before you can even take the first drink…
I don’t suffer from insanity…
I enjoy every minute of it!
Re: salt and beer.
Salt with beer is generally gross. But if you sprinkle a little salt on the napkin UNDER your beer the napkin will stay on the table when you lift your sweaty glass 
It’s true…a bartender did it with my beer once - she stuck her finger in the pint glass. I asked her about it and she confirmed the oil theory…I try not to think about the fact that when I get a tap beer that the bartender’s nose-oil is floating at the top of the liquid 
I’ve also heard that if you wash your ice before you pour the pop into the glass it also will reduce the amount of foam.
-Dragwyr
“If God had meant for man to eat waffles,
he would have given him lips like snowshoes”
-Rev. Billy C. Wirtz
Actually, I have a variation on the aforementioned trick, and after countless mornings employing the technique, I have a hypothesis for why both work. Instead of merely sticking my finger in the foam, I also scoop up a pea-sized glob of it, hold it 3-4 inches above the cup and flick it back in. Now, after initially putting my finger into my 44 oz. Pepsi, the bubbles start to disappear more quickly. Then, after I drop the glob of foam back in, the process really takes off, generally eating away an inch-thick head within 10 seconds.
My theory is that when someone sticks their finger into the foam, they force the bubbles they touch to burst more violently than they would normally, and that the additional force sets in motion a chain reaction which causes the bubbles to pop more quickly than they would of their own accord. My foam-dropping maneuver, I believe, heightens this effect, thereby speeding the process up much more.
Anyway, that’s my guess. I have nothing to back it up except many mornings of observationa and speculation.
This technique makes the ice smoother and thus reduces the number of nucleation sites which reduces the foam rate.
quote:
I’ve also heard that if you wash your ice before you pour the pop into the glass it also will reduce the amount of foam.
This technique makes the ice smoother and thus reduces the number of nucleation sites which reduces the foam rate.
while this is true, there is another effect that can crop up. If your freezer is set too cold, the ice will be cold enough to freeze the soda on contact (particularly if you keep your cokes cold as well ).
if you freeze a little bit of the soda on the ice, the disolved CO2 will come out of solution VERY quickly, without the need for nucleation sites so you get an extremely large number of very small bubbles that will then act as nucleation sitees for the rest of the soda.
if your ice is that cold, the coke will do some serious fizzing when you pour it. washing the ice will warm it enough to prevent this. of course, turning the freezer thermostat up a notch will do it even better and easier.
-luckie
As a quick side note, I have an older friend who shakes some salt into his beer because he claims it takes the edge off of the bitter taste. Never would do that myself, sounds nasty to me - but he has as long as I’ve known him. Odd huh.
"_ _ _ _ _ _ _ _ _ _ _ ".
It’s been a long time since my beer drinking days in the 70’s, but I remember a sort of fad had begun of sprinkling salt onto the head of your beer. From I recall, it was for no other reason but to add a salty taste to the beer (similar to sucking on a lime when drinking tequila).
I’d have looked her straight in the eye and told her it was an excellent method to quickly reduce her tip, too.
Cave Diem! Carpe Canem!
Ah, yes. Salt in beer.
If you are one not to guzzle a beer, but to linger lovingly over its flavor and aroma, (after you’ve guzzled the first one), then it can loose it’s head and fizz. A little salt added creates a reaction and gives it back more fizz and a little salty flavor – but not much.