Originally posted by: BigJ
Originally posted by: HomeBrewerDude
well, that would be a cold beer (retains more co2 per volume of beer) and a sealed keg (once removed, the keg will most likely be airtight and minimize the amount of co2 that can diffuse from the beer).
I suspect that the the OP left the tap on, and the beer was allowed to warm.... a shameful waste of beer IMO...
Good to know, thanks :thumbsup:
By the way, if you use the typical 'hand-pump' pressurization system, then you're not really maintaining your beer under the needed levels of co2. those hand pumps pump air into the keg, thereby introducing o2 and nitrogen (not particularily a problem as far as I know). Since gasses diffuse independent of each other, the only way to keep a beer to the intended level of carbonation is to keep it under pressure with a co2 tank and regulator.
For example, if you drink half a keg and decide to save the other half, then you're going to get the following:
1) a decrease in the amount of co2 dissolved into the beer
2) an increase in the amount of o2 dissolved into the beer
#1 will lead to a less fizzing, perhaps sweeter tasting and less bitter tasting brew.... not the end of the world because if this was the only thing happening (ie. there was only a loss of dissolved co2 in the beer) then you could just repressurize under 12-14 psi of co2 and youd be right back to where you started with virtually no ill effects to the beer.
#2 will lead to a change in the flavor profile. Oxidation occurs relatively quickly and can result in a cardboard flavor. There is no way to undo oxidation. Even if you recarbonate, you'll still have oxidized beer.