WineLovers Discussion Group

When you open a bottle of Champagne or sparkling wine there's a curl of 'smoke' coming out of the bottle.

I've always wondered what it was. Now the phenomenon has been explained in a way understandable to me, and named, in today's Daily Telegraph by Andrea Sella, an inorganic chemist at University College London, and Engineering and Physical Sciences Research Council Senior Media Fellow


"If you look quickly into the bottle you will see a small cloud floating inside that will dissipate in a few seconds: the result of the extremely rapid decompression of the small volume of gas in the neck of the bottle. Because of the speed at which this occurs, there is no time for the energy transfer – heating – to occur. The result is what meteorologists call adiabatic cooling – the temperature plunges to below -30C, causing the water vapour in the gas to condense."


Ms Sella's article is about beer but the effect must be the same -- full article is here. She also explains the formation of bubbles. Very interesting -- see http://www.telegraph.co.uk/science/5966 ... -beer.html

You can also get this effect if you inflate a bike tire until it pops. Not that I would have recent experience with that or anything.

Walt

Peter May wrote: Because of the speed at which this occurs, there is no time for the energy transfer – heating – to occur. The result is what meteorologists call adiabatic cooling – the temperature plunges to below -30C, causing the water vapour in the gas to condense."

It's not just metereologists who use that term: it's drawn from the field of thermodynamics (the movement of heat, i.e., energy). Adiabatic cooling and its reverse (adiabatic heating) are the basis of refrigeration, air conditioning and heat pumps. That's also the reason that a tire will get hot to the touch when inflated and that an aerosol can will get cool to the touch when expelling its contents.

Mark Lipton

Thanks for the link! I always kind of wondered what that was myself. I just assumed it must be pressure/carbonation related somehow but never really knew the specific science behind it...

Jeff

Mark Lipton wrote:

Peter May wrote: Because of the speed at which this occurs, there is no time for the energy transfer – heating – to occur. The result is what meteorologists call adiabatic cooling – the temperature plunges to below -30C, causing the water vapour in the gas to condense."

It's not just metereologists who use that term: it's drawn from the field of thermodynamics (the movement of heat, i.e., energy). Adiabatic cooling and its reverse (adiabatic heating) are the basis of refrigeration, air conditioning and heat pumps. That's also the reason that a tire will get hot to the touch when inflated and that an aerosol can will get cool to the touch when expelling its contents.

Yes, I too was wondering why metereologists should get a special mention. I would also expect ice particles at -30C rather than condensation. Nevertheless, an interesting article - thanks Peter.

when i was a kid we used to be able to let out a little puff of smoke from our mouths by increasing the pressure inside and then gently letting it out.

David Creighton wrote:when i was a kid we used to be able to let out a little puff of smoke from our mouths by increasing the pressure inside and then gently letting it out.

When I was young, I swear I never inhaled....oh, wrong sort of thread.....

Has any one ever seen this in a non-sparkling wine before? I saw it briefly upon opening a 1988 Lafaurie-Peyraguey last week.

Yup....will happen not infrequently with wines, young or mature, that have been particularly well sealed with no air-exchange whatsoever. Generally a momentary effect that goes rather unnoticed.

Best
Rogov