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Nitrogen/stout question

I have a cylinder of beergas 70/30 mix, a nitrogen regulator, a stout tap and a kegerator. My goal is to have my 5 gal. corny of Dry Irish Stout ready for St. Paddy’s day.

My questions are…

  1. What’s the best way to carbonate the beer? CO2 or the beergas?
  2. If beergas, what pressure should be used?
  3. What is the ideal carbonation level before being pushed with the beergas?
  4. Since the tap uses a restrictor disc, what should tge serving presure be and does it matter the beer line length?

Thanks!

Use CO2 to carb the beer before serving with beergas.

Thanks Denny, that’s what I assumed but a buddy was trying to convince me otherwise.
Any thoughts on the other questions?

  1. What’s the best way to carbonate the beer? CO2 or the beergas?
    like Denny said, co2

  2. If beergas, what pressure should be used?
    That depends on what carbonation level you want in your beer. If using a co2 carbonation chart, cross index your desired volumes of co2 with beer temp and see what pressure it tells you to apply. If using 70/30 beer gas to carbonate, it will take a much higher pressure, 30% of which will equal the co2 pressure indicated as required in the co2 carbonation chart. Since nitrogen gas is not soluble in liquid, only the co2 percentage of the gas used will provide the carbonation that will remain in the poured beer after the cascade effect from the nitro gas. Sometimes it’s hard for the co2 to make it past the compressed nitrogen gas in the headspace, to carbonate the beer. Some get around this by carbonating with beergas entering the keg via the beer out diptube, sometimes with an aeration stone attached to the bottom of the beer out diptube, to aerate with diffused gas from the bottom up. sounds like lots of hassle, so I just carbonate with co2 first.

  3. What is the ideal carbonation level before being pushed with the beergas?
    the style is often stated as around 1.8 to 2.5 volumes of co2, and with beer gas normally towards the lower end. I prefer it at the higher end. Still, I think a lot of the carbonation is stripped out during the beer gas pour.

  4. Since the tap uses a restrictor disc, what should the serving pressure be and does it matter the beer line length?
    Serving pressure depends on beer temperature and desired volumes of co2. I know a lot of people like to serve stout no colder than around 40F, but mine is in with other kegs, and I like beer cold (and it warms in the glass), so my kegerator is at 33F, and after carbing the stout with co2 I serve it with beer gas around 28PSI, via five feet of 3/16" beverage tubing. Per co2 carbonation chart, 8.4 psi at 33F will yield approx. 2.45 volumes of carbonation. Beergas at 28 psi x .3 = 8.4 psi from the % of co2 in the beergas.

My experience is that it’s better to start the beergas at around 25 psi and adjust upward after trying a couple pours, rather than to reduce carbonation in overcarbonated beer.

The Beer Styles Stout book is good reading and has a section on beer gas, and Chuck on this forum helped me dial this in better.

http://www.pjmuth.org/beerstuff/Carbonation_Table.xls

Wow! Thank you for the detailed response. That’s Awesome. I can’t wait to give it a try!

You bet. What you’re shooting for, is that once you’ve achieved your desired volumes of co2 by carbing with co2, you switch over to beer gas and do the math to keep the beer gas pressure high enough so that the co2 contribution (30% of total pressure) will keep your carbonation level where you got it by carbonating with co2.

In an ideal setup, will your serving lines be as long as your other serving lines? Or, would it be better to be longer? or shorter? I understand all of the other stuff, but am still trying to dial in “the perfect pour.” Trying to figure out if I need more restriction and higher Nitro pressure or less restriction from the lines and a lower nitro pressure.

Two issues I’m having are 1) Relatively large bubbles in the head, instead of a smooth tan layer. 2) Regardless of how I pour the pint – all at once, 75% then 25%, 50/50 – I can’t can’t get the perfect head on it. I’m starting to wonder if it has anything to do with my faucet or if I need a new restrictor disc. Or would a tweak to the recipe possibly be needed to solve these two issue. Good news is, the beer tastes great.

Sounds like a faucet or restrictor plate issue to me, or maybe a leak somewhere? I can tell you that I get a really good 1-inch tiny bubbles, lasting foamy head after a standard x2 pour, using 5 feet of beer line (same length as my other kegs) at ~28 psi at 33F, using a Micromatic stout faucet, with very little height change from the keg to the faucet. Micromatic sells a really nice stout faucet.

[quote=“FriendsR2Thirsty”]In an ideal setup, will your serving lines be as long as your other serving lines? Or, would it be better to be longer? or shorter? I understand all of the other stuff, but am still trying to dial in “the perfect pour.” Trying to figure out if I need more restriction and higher Nitro pressure or less restriction from the lines and a lower nitro pressure.

Two issues I’m having are 1) Relatively large bubbles in the head, instead of a smooth tan layer. 2) Regardless of how I pour the pint – all at once, 75% then 25%, 50/50 – I can’t can’t get the perfect head on it. I’m starting to wonder if it has anything to do with my faucet or if I need a new restrictor disc. Or would a tweak to the recipe possibly be needed to solve these two issue. Good news is, the beer tastes great.[/quote]

I would suggest that your beer isn’t carbonated enough. Might sound strange, but the same thing happened to me with my first nitro batch. Granted, nitro beers aren’t highly carbed, but they do need at least some carbonation for the faucet to work its magic.

Try increasing the carb a little bit more with CO2 only, and then trying pushing the beer again with beergas, and i’ll wager that you’ll get the effect you;re looking for. Might take some tweaking, but you’ll get there before you know it.

Bklmt2000

[quote=“Bklmt2000”]

I would suggest that your beer isn’t carbonated enough. Might sound strange, but the same thing happened to me with my first nitro batch. Granted, nitro beers aren’t highly carbed, but they do need at least some carbonation for the faucet to work its magic.

Bklmt2000[/quote]

So, I was getting large bubbles and a tall (> 1/3 of the glass) head. Is this what you got when it was UNDERcarbonated? I think I had it at about 1.7 volumes of CO2 before I released the pressure and then immediately hooked up the beergas to ~28 psi at 38F. If anything, I’d think this amount of head would be a sign of it being OVERcarbonated. My bigger concern is the large bubbles – it makes it look just like a poorly poured dark ale.

I’m getting a new faucet and restrictor plate on Friday, so hopefully that solves the problem.

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