CO2 vs Vacuum

[Confused Carl]

Howdy Folks,
Hope you're all doing just dandy here, help me settle an argument with my friend here would you kindly.

If I were to open 2 bottles of beer, drink half the beer in each then decide I needed to save the both the beers... I vacuum seal/cap one bottle, I replace air with CO2 in other bottle. Which would stay fresh longer? How much longer? Anyone randomly know the answer to that?
hahaah Thank you so much in advance, I've read over a few of the post here and I'm already very happy to have found this community.

 

[Pkrd]

If I were to open 2 bottles of beer, drink half the beer in each then decide I needed to save the both the beers... I vacuum seal/cap one bottle, I replace air with CO2 in other bottle. Which would stay fresh longer? How much longer? Anyone randomly know the answer to that?

In the vacuumed bottle the CO2 would escape from the beer to fill the bottle. Leaving flat beer behind.

You should really drink both.

 

[VikeMan]

I vacuum seal/cap one bottle, I replace air with CO2 in other bottle. Which would stay fresh longer?

If you could execute both perfectly, from an aging/freshness perspective, I'd expect them to behave the same. But as @Pkrd mentioned, the vacuum version would lose CO2 to the headspace and become flat. The CO2 version's beer may gain or lose CO2, depending on how much was in the beer to start with and how much you put in the headspace.

 

[Advance]

Both of these scenarios would result in destroyed beer. The vacuumed bottle would loose nearly all of its carbonation. The CO2 flushed bottle would suffer nearly the same result from the large headspace created by pouring out half the bottle's content. Both of the bottles would suffer from oxidation. Out of these two choices the CO2 flushed bottle will give you the better result, but it wont be any good. Your best option is to drink the entire bottle in one sitting, rather than destroying half by trying to save it for later date.

 

[Calder]

The CO2 one would fare better. Why would anyone leave half a beer?

 

[AlexKay]

If you evacuate the bottle, most (80-90%) of the CO2 in solution will go back into the headspace. If you add CO2 at the correct pressure, and there's nothing else in there, the beer will stay as if you had never opened it.

If you said vacuum was better and want to weasel out the bet with your friend, you could argue that the only feasible way to fill the headspace with only CO2 would be to evacuate it first...

 

[jddevinn]

Neither would work well as you oxidized the beer by drinking/pouring the first half.

I've used CO2 to flush the headspace in wine bottles to save for the next day..... but typically I just drink the whole bottle

 

[mcmeador]

Siphon the beer from one bottle to the other to give you a full bottle and then recap.