[flbrewer]

Any idea how long serving pressure would last on a keg without CO2 attached? I am debating between bringing a 2.5 gallon keg (would rather not bring a CO2 tank) or just filling up 2 gallon carboys.

This is for an upcoming festival where I'd be pouring beer for some non-beer folks.

[Stevie]

Any idea how long serving pressure would last on a keg without CO2 attached? I am debating between bringing a 2.5 gallon keg (would rather not bring a CO2 tank) or just filling up 2 gallon carboys.

This is for an upcoming festival where I'd be pouring beer for some non-beer folks.

Too many variable to say with certainty, but a couple of pints before the pour slows to a noticeable amount.

[Bob357]

If you start with a full keg you'll only get a couple of pints before you see a rapid drop in serving pressure because there won't be much CO2 that isn't dissolved in the beer. Starting with a less full will yield a few more pints, but the pressure will still drop fairly quickly after a few pints. Carbonation level and temperature are also factors, but to a lesser degree. 

If you plan on serving more than a few decent beers, bring CO2.