Carbon dioxide usage for brewing

I was wondering how long the CO2 tank should last when used for both carbonating and serving the beer.  The carbonation consumption is not insignificant.


  • 1 keg is 5 gallons
  • Carbonating to 2.2 volumes
  • Dispensing at 40°F
  • Dispensing at 12 PSI

There’s 0.134 cu ft/gallon. Thus, 5 gallon is 0.67 cu ft.

2.2 “volumes” means there is 2.2*0.67 = 1.47 cu ft of CO2 that is dissolved in the beer.

12 PSI is the same as 1.82 atmospheres.  Thus after dispensing all the beer, the empty keg has 1.22 cu ft of CO2 in it.

CO2 has a specific volume of ~8.2 cu ft/lb at 1.0 atmosphere and 40°F.  Thus, 2.69 cu ft is 0.33 lbs of C02 used per 5-gallon keg.

So, assuming no leaks (yeah right!), the 15 lb bottle should be good for about 45 kegs.

1 comment to Carbon dioxide usage for brewing

Leave a Reply




You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>