Alcohol in beer would evaporate extremely slowly in cold temperatures?

[malignant]

I'm guessing the alcohol in beer would evaporate extremely slowly in cold temperatures like a fridge. I hear a lot of people say otherwise, so I'm wondering if it even evaporates a noticeable amount in 24 hours?

 

[eigenperson]

It depends on the conditions inside the fridge.

If the fridge is airtight, then the worst-case scenario is that equilibrium is achieved and the entire fridge becomes filled to saturation with ethanol vapors. The vapor pressure of ethanol at 4°C is about 0.02 atmospheres, so if the interior of the fridge has a volume of 1 cubic meter, the amount of ethanol vapor at equilibrium is PV/RT = 0.9 mol, or 40 g. So it is theoretically possible that you could lose all the ethanol as long as your beer has less than 40 g of ethanol in it (probably the case unless you have put a lot of beer in the fridge).

But that is the worst-case scenario, and it will take a long time to achieve equilibrium unless you have dispersed the beer into an aerosol.

I would guess, roughly, that the concentration would not be noticeably changed after 24 hours, but probably would be after a week. Here is an example of a similar (informal) experiment. Of course, you could prevent even this by simply covering the beer.

 

[SteamKing]

I'm guessing the alcohol in beer would evaporate extremely slowly in cold temperatures like a fridge. I hear a lot of people say otherwise, so I'm wondering if it even evaporates a noticeable amount in 24 hours?

Is that why it's hard to keep beer in a refrigerator? People drink it up before it evaporates?

 

[Borek]

Who keeps their beer opened?

 

[SteamKing]

Well, in case the alcohol might evaporate thru the can, you want to drink it ASAP.