Nitros 70/30

[peebee]

That post by @Sorcerers Apprentice makes more sense of the "high/low" serving method: The "high" goes in first. It's how I remembered it explained to me (when I was knee high to a grasshopper ... etc.): Rows of glasses waiting for the foam to fall back before being topped up. Good-on-yer @Sorcerers Apprentice for posting that!

All the articles I've read have the "high" go in second. I'm somewhat doubting that now? All those articles wrong? Would explain why my attempts at "high/low" serving was a flop. @RoomWithABrew take note!




That above business with "partial pressure" is falling into place now too (separate subject!). And "Partial Pressure" returns to my slot of being Physics' "easy-peasy" subject. I was forgetting the reason for converting to "Absolute Pressure" in the first place: Things will get screwy trying to picture my schoolboy work on pressure, with "zero" offset from its real place by something mundane like "atmospheric pressure". Normality resumed (at least my idea of "normality"); I can get on with being a plain nutter again instead of trying to be a clever-****.

Times like these when it can be really handy having a proper reason for being an id'jet.

 

[peebee]

Heartened by putting to bed my anxieties of having worked out "Partial Pressure" wrong (I hadn't) and having memories of "high/low" stout serving refreshed (thanks @Sorcerers Apprentice), I can return to the subject: Nitrogen conditioning. Just a bit of a reminder: I'm a bit of a "cuckoo" on this forum (I'm not the only one!) and have a lifetime of support for CAMRA and hatred of "keg" (especially "nitro" keg!) behind me. I've moderated, but not entirely. As @Hazelwood Brewery is about to find out in a case of me "biting the hand that feeds me" ...

Nitro changes both the flavour and texture of the beer; it’s smooths any bitter roasty notes and it gives the beer a softer mouthfeel, some people describe it as more velvety. ...

I think I've picked out a similar line from you before? "Nitro" does indeed change the flavour and texture of beer, but it doesn't do it directly. It's a tasteless and very "neutral" gas. Quite the opposite of "carbon dioxide"! CO2 dissolves in the beer (stout) to create carbonic acid. It directly adds a taste to the beer ... sour! It makes spiky any bitter and roasty flavours (and does the same for many other flavours). And gives the beer a rough, harsh mouthfeel, that some people might describe as sandpaper. The unwelcome additions of CO2 are exaggerated by serving the beer (stout) cold. For light coloured "bright" beers many find these qualities acceptable, but for dark "heavier" beers (stout) they do not ... not even hardened "kegheads".

The use of large quantities (70%) of nitrogen in the CO2 dilutes and moderates the excesses of CO2. Nitrogen does impart its own "aesthetic" qualities, it is very difficult to get into solution, and likewise very difficult to get out, so lingers and maintains the head for much longer. Nitrogen also imparts another wholly aesthetic quality, in that the fine bubbles in suspension when the stout is poured "dance" in the glass to the amusement of the onlookers - I've never seen the clouds of fine CO2 bubbles dance in this way?

I do serve "stouts" on handpump. I do prefer a marginally higher carbonation levels for stout ... about 1.3 "volumes" of (pure) CO2. That's equivalent to just over 4psi of top pressure, of "pure" CO2, no N2! Ironically, that's a tiny bit more carbonation than many "nitro" keg stouts! I'll have more stout on for later in the year ... copies of post-WWII Whitbread Extra Stout (thanks to Ron Pattinson's grubbing about in library archives).

 

[Hazelwood Brewery]

Heartened by putting to bed my anxieties of having worked out "Partial Pressure" wrong (I hadn't) and having memories of "high/low" stout serving refreshed (thanks @Sorcerers Apprentice), I can return to the subject: Nitrogen conditioning. Just a bit of a reminder: I'm a bit of a "cuckoo" on this forum (I'm not the only one!) and have a lifetime of support for CAMRA and hatred of "keg" (especially "nitro" keg!) behind me. I've moderated, but not entirely. As @Hazelwood Brewery is about to find out in a case of me "biting the hand that feeds me" ...


I think I've picked out a similar line from you before? "Nitro" does indeed change the flavour and texture of beer, but it doesn't do it directly. It's a tasteless and very "neutral" gas. Quite the opposite of "carbon dioxide"! CO2 dissolves in the beer (stout) to create carbonic acid. It directly adds a taste to the beer ... sour! It makes spiky any bitter and roasty flavours (and does the same for many other flavours). And gives the beer a rough, harsh mouthfeel, that some people might describe as sandpaper. The unwelcome additions of CO2 are exaggerated by serving the beer (stout) cold. For light coloured "bright" beers many find these qualities acceptable, but for dark "heavier" beers (stout) they do not ... not even hardened "kegheads".

The use of large quantities (70%) of nitrogen in the CO2 dilutes and moderates the excesses of CO2. Nitrogen does impart its own "aesthetic" qualities, it is very difficult to get into solution, and likewise very difficult to get out, so lingers and maintains the head for much longer. Nitrogen also imparts another wholly aesthetic quality, in that the fine bubbles in suspension when the stout is poured "dance" in the glass to the amusement of the onlookers - I've never seen the clouds of fine CO2 bubbles dance in this way?

I do serve "stouts" on handpump. I do prefer a marginally higher carbonation levels for stout ... about 1.3 "volumes" of (pure) CO2. That's equivalent to just over 4psi of top pressure, of "pure" CO2, no N2! Ironically, that's a tiny bit more carbonation than many "nitro" keg stouts! I'll have more stout on for later in the year ... copies of post-WWII Whitbread Extra Stout (thanks to Ron Pattinson's grubbing about in library archives).

My delicate sensitive nature is unharmed. I do like nitro stout at about 1.2 volumes and I do like carbonated stout too. I don’t have favourites as such but might prefer one over the other at a given time.

I believe it might be the CO2 bubbles that drive the cascading effect - the CO2 bubbles are bigger and rise more quickly creating effects similar to convection currents in boiling water.

 

[RoomWithABrew]

One reason that the nitrogen generated head persists after pouring is that it's nitrogen bubbles have much less of gradient to exchange across approx 70% nitrogen to the 80% in air.
One pub I visited down here had a nectaron hopped ipa that they had on beer engine and on nitro pour, they said very similar but the beer engine serve was warmer.

Both awful ways to serve a west coast style ipa. When will these people learn taste and test the product before you put it on general sale.

 

[Frisp]

This may help take out the guesswork, and the maths!

View attachment 88825

I know its an old thread but worth asking the question
Have I got this right..
If I brew a stout (not under pressure), put it in a keg and crash it to 2C and pressurise to 41psi with 70/30 (30/70) and leave it to mature out Ifor a week or two I should have a Nitro stout.
My question is wont it explode out of the tap at that pressure? or is that where the correct nitro tap comes in?

 

[Sorcerers Apprentice]

It will, you'll need to drop it back to 28psi to serve it after 2 weeks of carbonation / nitrogenation

 

[Frisp]

It will, you'll need to drop it back to 28psi to serve it after 2 weeks of carbonation / nitrogenation

gotcha. Will it need half a mile of beerline the thickness of a mermaids hair to keep the flow in check?

 

[Sorcerers Apprentice]

You'll need a stout tap with a restriction plate or a stout spout attacked to a nuka tap etc

 

[Hazelwood Brewery]

I know its an old thread but worth asking the question
Have I got this right..
If I brew a stout (not under pressure), put it in a keg and crash it to 2C and pressurise to 41psi with 70/30 (30/70) and leave it to mature out Ifor a week or two I should have a Nitro stout.
My question is wont it explode out of the tap at that pressure? or is that where the correct nitro tap comes in?

Hi Frisp

Apply 40-ish psi, it will take up to a month to properly nitrogenate but you’ll have something nice in a couple of weeks.

You do need a stout spout with a restrictor plate and you dispense at the same 40-ish psi. If you drop the pressure to dispense you’ll just allow the gas to escape back out of the beer.

FYI, I have about 2m of 3/16 beer line between keg and stout spout.

 

[Sorcerers Apprentice]

Just be aware that the max pressure rating on nuka taps is 30psi, I've lost a half keg of beer and a cylinder of mixed gas , due to a seal blowing on the tap

 

[Sorcerers Apprentice]

As per attached image below

 

[Hazelwood Brewery]

As per attached image below


View attachment 92744

If your keg is at 40psi and you dispense the beer through 2m of 3/16 beer line the pressure presented to the tap will only be about 20psi (you lose 3psi/foot of 3/16 beer line).

 

[Frisp]

If your keg is at 40psi and you dispense the beer through 2m of 3/16 beer line the pressure presented to the tap will only be about 20psi (you lose 3psi/foot of 3/16 beer line).

great advice and will be incorporated into the Keggerator. one lager tap, one Stout / nitro tap and one reserved for Wez's "Big Kenny" AG brew

 

[AnimatedGIF]

I keep mine at 40psi, rather than dropping the pressure. Yes, you'll need a long length of 3/16, and stout tap as others have said.

 

[RoomWithABrew]

gotcha. Will it need half a mile of beerline the thickness of a mermaids hair to keep the flow in check?

No the stout tap does it for you. But you will get a lot of foam if there is too much CO2 in the beer.

 

[RoomWithABrew]

Just be aware that the max pressure rating on nuka taps is 30psi, I've lost a half keg of beer and a cylinder of mixed gas , due to a seal blowing on the tap

Or get a dedicated stout tap.

 

[YeastFace]

That disclaimer only appears to be on the flow control Nukatap, and not the regular one. Is there something in the design of the flow control which means it can't handle the pressure?

@Sorcerers Apprentice do you have the flow control or regular tap?

 

[Sorcerers Apprentice]

I've flow control taps, I'm not a fan of coils of beer line in my kegerator , it's really no big deal to throttle back on the pressure, and no impact on head height/carbonation. My regulator doesn't have a secondary gauge , however I use line pressure test gauge similar to this one
https://rlbs.ltd.uk/line-pressure-t...si-liquid-filled-gauge-with-rubber-cover.html

 

[kenstel]

Oh my word! That Porter in the BBC film looked good! I've no idea what most of this thread is about it whizzed right over my head (except for the partial pressures). Some day, I'd like to try whatever it is you're describing here!