Elevation change affecting carbonation levels in bottle conditioned beer?

Here's a question for some discussion:

If I brew, bottle, and age beer at 7,000 feet in elevation; then transport down to ~1200 feet in elevation - what affect would that have on carbonation levels?

The reason I ask is that I brewed a brown ale (at ~7,000 ft) that won a brozne in a competition in Phoenix (~1200 ft); with the judges commenting that the only thing that kept this out of the excellent category was too high of carbonation.

All of the other bottles of this beer that I've had at 7,000 ft have been perfectly carbed, but I guess the bottles in the competition almost over flowed when opened.

Yes, altitude will affect carbonation and head.

When going from low altitude to high altitude, you will get lots of head and little perceived carbonation. This is because with the lower atmospheric pressure at high altitudes, the dissolved CO2 in your beer comes out faster, leaving you with lots of head and little carbonation after even a few minutes.

When going from high altitude to low altitude, just the opposite happens. The higher atmospheric pressure lower down keeps more of the CO2 "locked into" your beer leaving you with less head and more carbonation for longer.

Hope this helps. There is more info in this thread: https://www.homebrewtalk.com/f128/altitude-carbonation-114569/

Most charts disclaim that the PSIG/Temp refs assume sea level and state that for every 200ft above SL to add 1psig.

Interesting observation, IMO, and raises another potential for debate about who should take that into consideration, the brewer or the judge?

Thanks for the link Parker - can't believe I missed that thread!

The scenario in the other thread seems to make more sense (bottled at lower elevation, and had higher release of CO2 when opened at higher elevation).

It is quite possible that what you consider perfectly carbonated is just a bit high for the style. A common problem for Browns and Porters.

david_42 said:

It is quite possible that what you consider perfectly carbonated is just a bit high for the style. A common problem for Browns and Porters.

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I thought about that, but both judges mentioned that the beer nearly overflowed when opened.

It doesn't do that when I open at 7,000 feet.

So do you have a carbonation issue with commercial beers that you open up there at +7,000 sea level? Like, everything seems low carbed?

Freezeblade said:

So do you have a carbonation issue with commercial beers that you open up there at +7,000 sea level? Like, everything seems low carbed?

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Nope - some commercial beers tend to seem a little over carbed at times (SNPA & Sam Adams come to mind).

The volumes of CO2 will be the same, the only difference will be the rate at which the CO2 comes out of solution.

Orangevango said:

The volumes of CO2 will be the same, the only difference will be the rate at which the CO2 comes out of solution.

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interesting point. I had never thought about that. The bubbles would also change size due to lessened preasure at elevation no?

That's the part I'm not understanding....

If I take a bag of doritos in Phx and drive up to Pinetop, the bag is way puffed up by the time I get to 7000 feet (the pressure inside the bag is the same, but the pressure outside is so much less???)

I'm just curious about this - fyi, I submitted the same beer to a competition in San Diego (near sea level obviously), so I'm curious as to what the carb (or head) level will be like....

Its not really the pressure inside the bag is the same its that the gas inside the bag is attempting to equalize with the pressure outside the bag. The bag is sealed so it can't expand enough.

Exactly...

As you go higher/lower, pressure tries to equalize. Since there is less pressure at 7000', the gas wants to get out of the bag, it always wants to travel high-low. If you open a water bottle at 7,000' and then seal it up and drive to sea level, the bottle will collapse. Again, the pressure inside is less and the outside pressure is pushing in.

This is the same concept in aircraft design. The fuselage has to be able to withstand being "blown up" so to speak. It is pressurised to 8,000' when you are traveling at 40,000'... that is a huge differential, about 7.8PSI.

Imagine if you will, all of the gases trapped in your body during a rapid decompression at 40,000' in an aircraft. Those gasses are kept in check at a canin altitude of 8,000'.... then POP immediately that pressure is lost. Rapid decompression is extremely painful as every gas in your body immediately expands. It basically knocks the wind out of you.

Your beer, has the same volume of CO2... but at HIGHER altitudes the CO2 will come out of solution faster, more readily. This is the same concept with boiling water at high elevations, the oxygen comes out of solution much more readily, reducing the ammount of heat needing to be applied.

The beer being over carbed at 1200' is perplexing, it should "seem" to be under carbed by the reduced rate of the CO2 escaping the solution, IMHO.

The Pol said:

The beer being over carbed at 1200' is perplexing, it should "seem" to be under carbed by the reduced rate of the CO2 escaping the solution, IMHO.

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That's my thought also - thanks for your input Pol....i hope to never experience pressure loss in an airplane - I hear that your ear drums pretty much burst as well

weird; we'll see what happens in the San Diego contest

It shouldnt make that much of a difference honestly. If you prime with enough sugar to make 2 volumes of CO2 then the beer will have 2 volumes of CO2. If you open it at a higher altitude, more bubbles should be seen rising to the top, and the beer will go flat more quickly. At a lower altitude, less bubbles will rise and the beer will reman carbonated longer.The perceived carbonation in the mouthfeel should be identical. You said that comertial beers did not have problems when you opened them up there, so why should your beer be any different?

My best guess, bad luck. You sent two over-carbed beers to comp. Perhaps your priming sugar was not thoroughly mixed enough.

Sounds like you'll need a third party to verify if it's elevation that caused the overcarbonation. Me being at 52' above sea level, I will reluctantly take some beer off your hands for 'research'

Honestly, I don't see how it can happen that way. Breweries around here ship beer all over the place, and I've never heard of overcarbonation problems. Deschutes Brewery's in Bend, OR and they're at 3625 ft, and their beers are carbonated fine for me.