What temperature is too cold to keep beer outside?

Reads 135203 • Replies 25 • Started Monday, December 21, 2009 7:16:32 PM CT

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DonMagi
beers 5592 º places 50 º 13:34 Tue 12/22/2009

Id be more worried about the beer being to hot at 27*

 
Narnad
beers 1521 º places 19 º 20:38 Tue 12/22/2009

All my science!

To solve this problem, you have to use the equation for freezing point depression. This tells you how much below the freezing point the solution will freeze. So the equation is….

ΔTf = Kf * mB

Where Kf = constant for water (1.86 (kg*K)/mol)

Where mB = molality of the solute (mol/g)

Molality = moles of solute / (kg of solvent)

When dealing with a solution, your lesser volume is going to be referred to as your solute (here ethanol) and the greater volume is the solvent (H20). Assuming that 5% alcohol, we can use our knowledge of percentages and represent our solute and solvent as 5g of alcohol/100g of H2O.

Ethanol = CH3CH2OH = 46g EtOH = 1 mole

So to solver our mB portion of the equations we have to calculate the moles of solute….

5 g EtOH x 1 mole EtOH = 0.10369 moles EtOH
46 g EtOH


then the mass of solvent…..100g of H2O = 0.1 kg of H2O


So filling in the formula gives…..

ΔTf = 1.86 kg*K x 0.10369 moles = 1.928 K = 1.928 degrees C
Mol 0.1 kg


Since water freezes at 0 C (32 F), the freezing point depression would be subtracted so we get –1.923 C or 28.54 F.

So a 5% OH beer would freeze at 28.54 F, which makes sense. Ever leave a beer in the freezer too long?

At 8% its 26.18 F and 10% would be 24.722, just to cover the range beer your most likely going to be carrying around on any given day.

And just in case that beer is a Brew Dog Tactical Nulcear Penguin (32% OH), 8.7 F would freeze that mother of a beer.

Enjoy!

 
tennisjoel
beers 1633 º places 39 º 21:42 Tue 12/22/2009

Originally posted by shawn14505
I was wondering this myself, so I have been experimenting (hiding beer from the wife) a little bit the last few days/weeks here in upstate NY. I’ve been keeping 9-10%ABV beers inside my car (not the trunk) and it’s gotten down to the mid teens overnight without a problem. Granted the car is stared and warmed up to temp at 6am every morning, so it’s not a constant temp. And I can bet that it dosen’t get anywhere near that temp inside the car during the 10-12 hours that it sits overnight. No freeing/damage. Beers were Harpoon Leviathan DIPA and Simcoe DIPA.




I would guess 9-10% would be fine in those temps. If the car is in a garage, it tends to be a bit warmer than if left outside.

 
DerWeg
beers 1842 º places 45 º 17:53 Wed 12/23/2009

Abosulte Zero would be a little harsh for a beer.

 
User37895
beers 3085 º places 92 º 20:20 Wed 12/23/2009

Originally posted by Narnad
All my science!

To solve this problem, you have to use the equation for freezing point depression. This tells you how much below the freezing point the solution will freeze. So the equation is….

ΔTf = Kf * mB

Where Kf = constant for water (1.86 (kg*K)/mol)

Where mB = molality of the solute (mol/g)

Molality = moles of solute / (kg of solvent)

When dealing with a solution, your lesser volume is going to be referred to as your solute (here ethanol) and the greater volume is the solvent (H20). Assuming that 5% alcohol, we can use our knowledge of percentages and represent our solute and solvent as 5g of alcohol/100g of H2O.

Ethanol = CH3CH2OH = 46g EtOH = 1 mole

So to solver our mB portion of the equations we have to calculate the moles of solute….

5 g EtOH x 1 mole EtOH = 0.10369 moles EtOH
46 g EtOH


then the mass of solvent…..100g of H2O = 0.1 kg of H2O


So filling in the formula gives…..

ΔTf = 1.86 kg*K x 0.10369 moles = 1.928 K = 1.928 degrees C
Mol 0.1 kg


Since water freezes at 0 C (32 F), the freezing point depression would be subtracted so we get –1.923 C or 28.54 F.

So a 5% OH beer would freeze at 28.54 F, which makes sense. Ever leave a beer in the freezer too long?

At 8% its 26.18 F and 10% would be 24.722, just to cover the range beer your most likely going to be carrying around on any given day.

And just in case that beer is a Brew Dog Tactical Nulcear Penguin (32% OH), 8.7 F would freeze that mother of a beer.

Enjoy!



I didn’t proof-read all of the math, but the approach is correct for lower fraction ethanol solutions in water: freezing point depression principle, the same one that drives dropping salt on ice so it turns to liquid at lower temperatures than the normal freezing point. The amount of salt required is lower on a mole% basis, because more ion "particles" are created for salt than for an organic whole molecule like ethanol.

The trend is only good to a point, though, because in binary mixtures, at some point, the ethanol freezing point dominates the shift rather than freezing point depression. You can see this trend at higher ethanol fractions (especially those well above any beer) in the following:

http://www.engineeringtoolbox.com/ethanol-water-d_989.html

25F of actual temperature is where you can start to worry for most beers. But, realize, as others have stated, that freezing is an equilibrium phenomena. Kinetics of freezing are dictated by heat transfer, the rates of which are determined by the temperature differential between the environment and the substance here, beer. A couple of degrees of temperature difference is not going to make things freeze quickly. A lot of energy goes into the process of freezing, so you could be waiting a while to freeze beer in 24F weather. And, this doesn’t even factor in the fact that the warm air in the car (when it was turned off) is somewhat of an insulator from the outside environment. My guess is that your beer would be fine at 25F for overnight.