Leaving bottle or can cases of beer in car overnight. How low can outside temps go before bottles or cans are in danger of bursting?
That would be entierly dependent on temprature. If it was exactly 32 and the car was stored in an attached garage, I think a few days would be fine. If it was -10 and the car was out in the driveway in the shade I would think only a matter of hours.
Not exactly the same thing but…
I started keeping soda and Propel flavored water in my car, which is outside all the time. If the temperature is below about 20-25 degrees it will freeze overnight. There will be some residual heat trapped in your car that keeps it just slightly warmer than the outside temperature. I’m guessing if you haven’t driven your car for a couple days it would be closer to the outside temp and freeze faster.
Googling suggests that the freezing point of beer is around 28 F (- 2 C). Clearly the precise temperature will depend on the alcohol content. Overnight, the temperature inside of a car will equalize with the outside temperature, so the answer to the OP’s question would seem to be 28 degrees.
(Note: I was surprised to see that Googling “beer freezing temperature” produces all sorts of links with the notation “This site may harm your computer.” This includes a Wiki entry on the subject.)
Reading this thread prompted me just now to go get the three cases of beer I left in my truck yesterday afternoon and bring them in. It got to -7C (19F) last night; the cans weren’t frozen or even close to it.
The answer here, as usual, depends. You can freeze beer at just a couple degrees below freezing, or you can leave it in the car at -30 and not freeze it. When beer would freeze at a given temperature is dependent on:
the size of can or bottle,
how many are in the case,
what type of case it is,
how the cases are packed,
where in the vehicle they are packed,
how warm the beer was to start,
how long “overnight” is,
and the alcohol content of the beer.
A standard 355ml aluminum can will freeze much quicker than a 1L bottle or those mini keg-cans; surface area to volume thing. One single beer will hold less heat than 24 all crammed tight against each other. A bunch of bottles sitting in 2 rows in an open-top cardboard case will cool of faster than cans packed into those near cubic insulated cases sometimes sold. The beer will also hold it’s heat better if all the cases are tighly packed against each other and covered with a coat or blanket. They’ll stay warmer longer if placed on the seat near the center of the vehicle rather than on the floorboard in the trunk… certain parts of the car/truck cool off faster than others. If the beer was already chilled when you bought it and stuffed it in the cold trunk then it’ll freeze a few hours sooner than if you bought it at room temperature and kept in in the passenger compartment next the the heater duct for the ride home. “Overnight” might be from 11pm to 5am… or from yesterday afternoon to late the next morning (as it was in my case). In general I’d recommend not leaving beer in an outdoor vehicle overnight if it’s forcast to get much below -10C that night.
At any rate, I’ve frozen beer numerous times, and only once did one can bulge on the bottom (but not burst). If the cans are decent quality, you can freeze them solid and thaw them out no problem. Sometimes they lose carbonation and taste off after freezing, sometimes not. It’s usually a good idea to drink the previously frozen beer after you’ve had a few fresh ones; by then you won’t even notice the difference.