Why the seltzer always explodes?

June 17, 2015 4:32 PM

Why does seltzer explode on the regular but flavored sodas rarely do under the same conditions?

I guess I'm not as good at googling as I thought.
When I buy a commercial bottle (let's say a plastic 1L bottle) of unflavored seltzer or club soda, opening it to drink, whether cold or room temperature (assume it's been sitting still for a while) regularly turns into a mess, and can explode out of the bottle.
A 1L bottle of diet coke, sprite, whatever, rarely does this (assume similar conditions to my seltzer). Why?
I'm guessing something about sugar, aspartame, coloring agents, etc is the reason, but I'd really like you to throw some science at me! (I'm not interested in your special technique for opening seltzer. I just want to know why and what the difference is between the two scenarios)

posted by atomicstone to Science & Nature (5 answers total)

According to Steve Spangler Science, diet soda is still more prone to exploding than regularly sweetened soda. They don't know why:

Some scientists speculate that diet sodas contain more carbon dioxide gas while others believe that there is a unique interaction that goes on between the artificial sweetener, the preservatives, and the carbonated water. No one fully understands the reason.

I can't find a more academic source than that, although there are various results from medical journals about eye injuries caused by exploding carbonated drinks.
posted by Rangi at 4:57 PM on June 17, 2015 [2 favorites]

Is seltzer or club soda more carbonated than the average soda? I've noticed with my soda stream if I over carbonate the water it can get real messy when I add the flavoring.
posted by COD at 5:19 PM on June 17, 2015

Maybe viscosity has something to do with it?
posted by oceanjesse at 8:53 PM on June 17, 2015

COD alludes to my thought; this has to do with nucleation points, the same way the mentos/diet coke thing works. Perhaps the seltzer can have more carbonation dissolved in it than other things and when you release the pressure it releases. Alternately, perhaps the lack of other things dissolved in it makes it more sensitive to being shaken up.
posted by phearlez at 8:23 AM on June 18, 2015

I believe soda companies regulate the CO2 content based on the pressure in the bottle. Pressures can vary based on product, bottle size, and bottle material.
posted by SemiSalt at 11:58 AM on June 18, 2015