80% CO2, 20% N2 - possible, yeah?

Long story made real short:

I have a custom long draw system that essentially requires that I keep my beers at 17psi in order to serve them. If they are any lower than 17psi, the system coughs and sputters. This has been verified twice now by a certified draft technician. Obviously, 17psi is over carbonating the beers.

What I want is an 80/20 mix of CO2/N2 to keep the pressure up at 17psi, but only keep 13-14psi of actual CO2 on the beers. Draft tech confirmed this was my best route.

I asked for this at my usual gas supply and they looked at me like I was crazy. I asked for an explanation as to why this wasn’t possible, and he said it ‘just isn’t’. ‘I just can’t put nitrogen in a CO2 bottle’ was his main caveat, which I then asked if he could do it in a N2 bottle. That didn’t fly either. I understand that N2 is bottled at a higher pressure than CO2, so I’m not sure I understand why an N2 bottle cannot be used.

So… question is: is this possible or can someone explain why it isn’t possible?

I thought beergas was an 80/20 mix? Perhaps there’s another place you can get it?

I think typical beer gas is 75/25. I would go with that and call it good as the alternate solution would be a blender which run over $600. Blender would also require dual tanks or a nitrogen generator.

I think the issue with using regular beer gas is that it’s 75% nitrogen and 25% CO2.  AmandaK is looking for 20% nitrogen and 80% CO2.

Bingo.

Oh, I had them backwards. Whoops. I guess that complicates the issue.

Yeah, we’re wrong. Blender might be your best option. I don’t think many companies would want to bottle custom blends for a homebrewer, and if they did the price would likely be insane.

Is it feasible to swap your lines for something that will let you run at a lower pressure?

What diameter, material, and line length are you using? Is your tap higher or lower than your keg and by how much? If you can’t easily change the line length or height difference you can also change the diameter and material of the line. All of those things play together.

I’m sure if you had a draft technician out they’ve helped look at those things, though.

Not sure of total length, but I know she is running up 1 floor and not directly above IIRC from her There’s always a project at the Redbird brewery thread in pimp my system. I think she has a pretty unique system that fits her needs and requires special consideration.  I don’t have the answers she needs but do “think” I remember those facts from that thread

I’m leaning this way, but I don’t really want to have another thing to tinker with.

I have a 70/30 N2/CO2 bottle (kinda beer gas) and a 100% CO2 bottle. The CO2 bottle has a dual pressure regulator on it (and two manifolds for what is 100% CO2 now). What I’m thinking is that I’ll use a gas blender for my “normal beer manifold”, blending the beer gas and the CO2 for my “normal beer manifold”. Then I’ll have straight CO2 for my “high carb manifold”. Then have the beer gas straight for my stout tap. Ugh.

May have to pull the bottles out of the keezer and make some sort of pass through. I remember seeing a thread about that a month or so ago, and I liked Mark’s design, but I can’t find it anymore. :frowning:

I suspect this is actually the reason it ‘can’t be done’, but being the person I am I want to know precisely why.

Yep.

Pretty good memory, Frank! It’s about a half a floor (split level home), but otherwise spot on. Link is in my signature.

Yes, but I hated the lines. I can use the normal ol’ vinyl lines (1.4" ID, 1/2" OD), but they have a LOT of flavor carryover from beer to beer to mead to cider. I also had to dump the first 1/4-1/3 of a beer due to ‘line beer’. I am not willing to compromise this. I run Micromatic Brewmaster II barrier lines and have absolutely zero issue with flavor carryover. Hell, I can run water through the lines after running a berry-laden hydromel through them and have no flavor carryover into the water. And that makes me happy.

Yes, I am very picky.  :wink:

Side bar: I’m kinda surprised that there isn’t a gas vendor lurking on here. Still curious about the 80/20 CO2/N2 blend question.

You need a gas blender, then two tanks; one each of CO2 and N2. Then you can blend your own and maintain partial pressures where they need to be. Also means you can use straight CO2 if you need to fast carb, and straight N2 if you want to keg still wines or meads. :slight_smile:

There are pictures of his setup in the following thread:

https://www.homebrewersassociation.org/forum/index.php?topic=25373.0

Thaaaaank you. Was using the wrong search terms over here.

Man, it’s sad to see Mark’s username in “Guest” status. I think we must’ve drilled him too hard with questions and burnt him out. That’s a bummer…

That’s not what happened.  See reply #7 in the thread titled “The Pub?”.

Thanks for the PM. What a f*cked up situation.