Carbing with Mixed gas

[DBakes15]

Hey guys,

We have 4 7BBL single wall brites in our walking cooler. I was wondering if there is any issues that would occur from carbonating using the 80/20 gas blend that is already going into out walk in cooler.

Cheers,

[Richard Pivo]

Hey guys,

We have 4 7BBL single wall brites in our walking cooler. I was wondering if there is any issues that would occur from carbonating using the 80/20 gas blend that is already going into out walk in cooler.

Cheers,

Nitrogen is far less soluble than co2. Meaning that almost none of the nitro will stay in solution when there is also co2 being introduced. The nitro will basically work to scrub aromatics out of your beer and into the head space. Using a blended gas will most likely also lead to more time spent trying to carb up your beer. Gas blends are typically use only when a higher pressure is needed to balance a long draft than co2 alone can provide in equalibrum. My advice: run a pure co2 line into your cold room for carbing and use the blended only for head pressure for serving.

[TGTimm]

You need to look at your gas laws. The partial pressure of the CO2 is what you will be using to determine your carb level, and CO2 is only 20% of the mix. I doubt your bright tanks will handle the pressure. Use CO2. CO2 is also cheaper than mix.

[jebzter]

Not to mention that you will need much higher pressures to get to the desired carbonation levels. An example using our carb temps here at the brewery:
100% CO2 @ 33F Beer temperature=11psi is the saturation pressure to get 2.6vol
80% CO2 @ 33F Beer temperature=17psi is saturation pressure to get to 2.6vol

I assume these are serving tanks, so they are in a walk-in at 38 ish degrees. That puts your saturation pressure at 20psi for 2.6 volumes. Unless you have ASME pressure rated tanks, you shouldnt exceed 14.9psi and your pressure reliefs will be set that way.

Considiering also the issue that 20% of what you bubble in goes straight to the headspace and can help liberate aromas with it, I would suggest not using a blend. Further, you should only be using a blend on long draw draught systems, if it is direct draw, consider 100% CO2. There are also some pro's to using pneumatic pumps to send your beer the distance vs using a gas blend.