Serving while carbonating

[whm3223]

This is a point of contention in our small brewpub, so if anyone would care to weigh in I'd appreciate it.

We are force carbing multiple kegs on the same manifold as kegs hooked in to serve on draft. However, we only serve beers here for events, maybe a couple hours a week. Could this beer service lengthen the carbonation process because of a thinner distribution of the C02?

[TGTimm]

You're opening up a can of worms, there.

If you're carbonating and serving at the same pressures, you'll end up with under- or over-carbed beer and foam at the tap. Generally, your beer carbonation equilibrium pressure will be lower than your serving pressure. Service lines require higher pressure to get the beer to the tap--unless your lines are really, really, short. If your beer is sitting almost all the time at serving pressure, it will over-carbonate and serve as foam.

You need separate regulators and manifolds for the force-carbing and serving. No big deal. Since you're only serving a "couple hours a week", you might consider using a CO2/N2 gas mix for your service lines--this will allow you to keep the partial pressure of your beer at its CO2 equilibrium pressure, while having enough pressure from the N2 to push the beer to the tap. N2 is poorly soluble in beer, so it doesn't change the quality of the beer like excess CO2 pressure will.

Download the Draught Beer Quality Manual and read it--you'll thank yourself later--and your customers will thank you, too.

While you're at the computer, read this: http://www.meheen.com/support/education/

[lhall]

TGTimm,

I almost always agree with you, but I think part of what you said is incorrect. The keg needs to be set at the correct pressure and temperature to maintain the carbonation level that you want. If you set the pressure higher than the equilibrium pressure, the beer will gradually pick up extra carbonation. Then you design the restriction of the draft line to the pressure of the keg.

If you are force-carbonating a keg, you'll have faster results by turning the CO2 pressure up to about 30 psi overnight, and then checking it. It will take a long time to carbonate a keg at normal serving pressures of 10-12 psi of CO2.

[TGTimm]

TGTimm,

I almost always agree with you, but I think part of what you said is incorrect. The keg needs to be set at the correct pressure and temperature to maintain the carbonation level that you want. If you set the pressure higher than the equilibrium pressure, the beer will gradually pick up extra carbonation. Then you design the restriction of the draft line to the pressure of the keg.

Well, that's what I meant to say... the carbonation, equilibrium, and serving pressures will all be different. Regulator=cheap, poor pours/over-/under-carbed beer=very expensive.