The Auswine Forum

I’ve a question for those more science minded than myself. When used for cooking, does wine retain its alcohol or does it loose it? I pondered this as I was pouring half a bottle of Riesling into a seafood dish last night.

cheers
Ian

Alcohol is much more volatile than water and will quite quickly evaporate from the hot cooking pot. If you don't want to waste it, stick your head over the pot and breathe deeply.

Red Bigot wrote:Alcohol is much more volatile than water and will quite quickly evaporate from the hot cooking pot. If you don't want to waste it, stick your head over the pot and breathe deeply.

Brian, does that mean the rate of alcohol evaporation is determined by temperature. High temp = rapid evaporation, lower temp reduces the rate? The reason I asked is because as I was cooking it struck me that perhaps decanting has an affect on alc/vol? If a wine is left to sit in a decanter for 4-5 hours, will the alc/vol reduce?

Boiling point of alcohol is 78 degC.
If you want alcohol in your food stay below this.

Regards
John

Irregular wrote:

Red Bigot wrote:Alcohol is much more volatile than water and will quite quickly evaporate from the hot cooking pot. If you don't want to waste it, stick your head over the pot and breathe deeply.

Brian, does that mean the rate of alcohol evaporation is determined by temperature. High temp = rapid evaporation, lower temp reduces the rate? The reason I asked is because as I was cooking it struck me that perhaps decanting has an affect on alc/vol? If a wine is left to sit in a decanter for 4-5 hours, will the alc/vol reduce?

Oh dear. 2nd year physical chemistry

To keep a complicated story simple you are right in thinking that the temperature or heat that you put into the substance affects the rate of evaporation. Ethanol has a higher vapour pressure and thus a lower boiling point than water so would evaporate faster. But then you want to talk about a solution of the two together.

Interestingly when you mix water and ethanol you actually get some interaction between the two substances and the evaporation of the mixture is faster than expected as well (positive deviation from Raoult's Law).

The ethanol component should evaporate faster than the water at room temperature but a significant decrease in concentration would take a matter of days (haven't done the maths but remember an isopropyl alcohol experiment where we measured concentration over a few weeks)

Acetic acid formation would be faster I suspect

I add the caveat that 2nd year was a while back now so could easily be incorrect on this!

cheers

Carl

Thanks all, I think that clears it up

Irregular wrote:Thanks all, I think that clears it up

OK, how about:

Alcohol will evaporate faster than water so alcohol concentration will reduce but the time taken is slow so 4-5 hours in the decanter isn't going to make a difference.

cheers

Carl

Ian,

I find that a bit of dry sherry works very well in seafood dishes, especially pasta sauces. And the oakiest, but cheap, Chardonnay does wonders for a seafood soup when you put in a cup or two just before serving. However, don't sniff too close to the steaming pot right after pouring in the wine unless you want to "burn" your nostrils. I learned the hard way.

So perhaps that answers your question about alcohol evaporating.

Cheers..................Mahmoud.