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SpaghettiMonster 04-16-2009 05:33 PM

Altitude and carbonation
 
Not sure it this is the right section or not but I had a question on carbonation. Recently I made a batch of honey porter and I split it with my mom (each got a case). So the few Iíve opened so far have been carbonated OK, maybe even a tad under carbonated (Mesa, AZ, 1,300 ft). My mom spent the weekend in Munds Park (7,000 ft) and she said they seemed way over carbonated. Now it could be that I just didnít mix the priming solution well but I havenít had that problem before so I was wonder if it could have been due to the altitude. Anybody run into this before? Would the carbonation eventually die back down it they were to keep the beer up there? Etc. Etc.
Thanks

menschmaschine 04-16-2009 05:42 PM

I think the key is the pressure (atmospheric) difference between where it was bottled and where it was opened. When bottled at your altitude, that essentially bottled in your atmospheric pressure. It could be that they weren't really over carbonated, but that the pressure difference between bottling location and opening location caused more CO2 to come out of solution (and gas expansion?), creating more foam (but not more carbonation).

SpaghettiMonster 04-16-2009 05:51 PM

Ok, that's what my thought was (sorry for the wrong terminology carb vs. foam). So do you think that over time the CO2 would be released slower if say the beer sat for a month at the higher altituted?

menschmaschine 04-16-2009 05:56 PM

Quote:

Originally Posted by SpaghettiMonster (Post 1265545)
Ok, that's what my thought was (sorry for the wrong terminology carb vs. foam). So do you think that over time the CO2 would be released slower if say the beer sat for a month at the higher altituted?

I'd say no. You locked in your atmospheric pressure when you put the cap on. There's no way for it to equilibriate to a new atmospheric pressure without opening it.

SpaghettiMonster 04-16-2009 06:06 PM

Quote:

Originally Posted by menschmaschine (Post 1265557)
I'd say no. You locked in your atmospheric pressure when you put the cap on. There's no way for it to equilibriate to a new atmospheric pressure without opening it.

Yeah, I guess that makes sense thanks. I'll give you an update this weekend when she had some back here in the valley if they've returned to 'normal'.
Thanks

z987k 04-23-2009 03:50 PM

While it was capped at your atm pressure, when it carbonated, it went well above that, as in a much much lower altitude. Probably in the range of a positive 10-12psi, depending.
Since each gas acts independently, when you open a carbonated bottle, it will try to reach equilibrium with the partial pressure of that gas, and since the partial pressure of CO2 is lower at 7,000' than 1300', more CO2 will come out of solution at 7k than 1.3k. Also remember that the volume of a gas is inversely proportional to it's pressure (assuming constant temperature.) So there is a good deal of expansion going on.

TheChemist 05-24-2009 09:10 AM

Can't speak to pressure (I am clueless on that), but I know that temp would have a big impact. Is it possible your mum just stored the beers at a higher temperature, and didn't chill as well before opening?

althalos 06-01-2009 05:34 PM

I actually think you may have been on the right track. The interior pressure will be the same, but when you open it at higher altitude/lower atm pressure, it will effervesce more vigorously to attempt to reach equilibrium with the lower pressure, so it will SEEM to be overly carbonated.

Phunhog 06-05-2009 02:16 AM

Wow what a timely thread! I just bottled 4 different beers for the Telluride Bluegrass Festival, which is at 9,000ft. However I live at the beach so that is quite a difference. I just hope that my beer is not overly carbonated, or at least taste that way.

Kaiser 06-05-2009 04:51 AM

Has anyone noticed this with commercial beers which we can assume to have a standardized CO2 content? At least for the large national brands. It certainly would make sense that beers seem more carbonated in Denver than on the coast.

Kai


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