# Why does meltwater taste different?

I've noticed that water obtained from melting ice cubes (by keeping them in the open) tastes different from water cooled to the same temperature.

Furthermore, the taste goes away if you keep it in the open for a sufficient duration of time.

I can think of these possible explanations:

• Dissolved gases being released
• Something to do with the crystal structure of ice
• Something to do with dissolved minerals

The Internet is giving me all sorts of varying answers.

Exactly what chemical differences exist between meltwater and cold water?

• I might guess the dissolved gases (and specifically the chlorine/chloramine) would be ejected faster from melted ice (and slowly from standing water), but I don't know if that's the taste you're looking for. – Nick T Jun 4 '12 at 3:25
• @NickT: I'm not looking for the taste, I'm looking for all the physical/chemical differences. The taste is just a point proving the existence of those differences. You can make that into an answer, though I'd prefer something more than a "guess" ;-) – ManishEarth Jun 4 '12 at 8:24

(not yet a fully grown answer: experiment still pending)

I heard that $\ce{CO2}$/$\ce{H2CO3}$/$\ce{HCO3-}$ is responsible for "fresh" taste of water.

@NickT: Chloramine has a very characteristic smell, so Manishearth could most probably tell us whether this was the smell/taste.

So, here are first questions for @Manishearth:

• does water that has been boiled and then cooled to the same temperature taste similar to the taste you're asking for?

• What about de-ionized water?

Of course, there's also that average-of-all-that-has-ever-been-in-the-freezer taste...

• Nope, boiled water tastes bland, even when cooled. Regarding chloramine, I don't know the smell, but I don't think that that's it (if you want to check it out, lick an ice cube). I remember drinking from a stream in Yellowstone(meltwater), it had the same taste. So it's something natural, not having to do with artificial additions. – ManishEarth Jun 4 '12 at 17:27
• @Manishearth: Chloramine is the "chlorinated" smell of swimming pools or sometimes drinking water (at least here in europe). I was asking about the boiled water because boilings gets rid of dissolved gas - like freezing. So now we know that you're looking for something that is not caused by loosing a gas. But I have to admit I have no idea what it is... any food chemists around? – cbeleites Jun 7 '12 at 21:43
• Nope, not that taste. And never tasted it in drinking water. – ManishEarth Jun 8 '12 at 0:19

Oxygen solubility is 10 mg/L for water, and 14.5 mg/L for ice. Even after the ice melts to room temperature, the oxygen level in the melted ice water remains higher than the water that kept a constant room temperature(~12 mg/L vs 10 mg/L). The extra oxygen present is most likely the cause for the difference in taste.

I read it had to do with dissolved gasses, that "normal tasting" water has the dissolved gas but freezing water you lose the gasses. So I tried this home experiment. I froze water then let melt and tasted it, it tasted bad with the off flavor. Then I took out a large freezer bag and only put a small amount of the foul tasting water. I then shook it violently for some time to mix air back into the water. Boom the water tasted fine again. No double blind here but seriously is it needed?