Nitro carbing issue

[Logman]

My Nitro head gets larger the longer the keg has been hooked up. I leave it connected the whole time so maybe that's an issue - it's on around 200 and it's a 70 nitro/30 co2 mix.

I roll around the keg for around 30 seconds on Co2 at first before hooking up the Nitro and at first it gives a great pour. But after a few days the head starts getting larger.

I'm not really sure of the carbing process with this mix so I figured I'd ask as it's $^%#ing me off. Will this keep carbing if it's just left on long enough or is the issue something else - i.e. does 70/30 not really carb the beer enough to cause this issue?

 

[Bribie G]

I don't always do a Nitro beer, but when I do I also get that situation. I guess because we are pressurising at a rate that would make CO2 carbonators faint, then that 30% of CO2 is going to get gradually forced into the beer until it reaches some sort of equilibrium point vs the Nitrogen. Maybe commercial places like pubs and clubs go through the kegs too quickly to get the problem?

Do you think that the rolling around thing precarbs the beer enough? I'm thinking that if you do a more steady pre-carb (edit, using your CO2 supply) at a fairly low pressure for a couple of days then on switching to the pub mix, this could perhaps obtain that equilibrium point straight away. Ross is a bit of a nitro expert and he might be able to advise if he spots this post.

 

[stux]

Now we just need the ability to tag people in posts

 

[Logman]

I don't always do a Nitro beer, but when I do I also get that situation. I guess because we are pressurising at a rate that would make CO2 carbonators faint, then that 30% of CO2 is going to get gradually forced into the beer until it reaches some sort of equilibrium point vs the Nitrogen. Maybe commercial places like pubs and clubs go through the kegs too quickly to get the problem?

I figured this was what was probably going on but wasn't sure. The only thing I could think of was to pull it out of the keezer overnight when the keg's half full and open the PRV or something.

Do you think that the rolling around thing precarbs the beer enough? I'm thinking that if you do a more steady pre-carb (edit, using your CO2 supply) at a fairly low pressure for a couple of days then on switching to the pub mix, this could perhaps obtain that equilibrium point straight away. Ross is a bit of a nitro expert and he might be able to advise if he spots this post.

I've got a spare Co2 bottle in the garage, never thought of carbing it to 30 or so before putting it in - any idea what the correct Co2 is?

Going to the next BB so I'll ask Ross if I don't know by then. Can't remember asking him if he keeps it hooked up permanently.

Stay thirsty my friend :beer:

 

[NickB]

I would assume its because, lets say, if we are carbing a regular keg with CO2 to 70KPa and pouring at that pressure, it would seem to me that if we are serving on a 70/30 Nitro mix at 200KPa, then the keg would be absorbing approx 90% of our normal carbonation - CO2 at 30% of mix, but at 3x the pressure... My maths may be off.....

Just a thought - and I have the exact same issue as both above.

 

[Logman]

Just remembering that they had a perfect pour at CB now that I think of it so maybe we are making a mistake somewhere.

Sent Ross an email to ask if he can shed any light on this topic :huh:

 

[Murdoch]

When I gas a nitro beer at home I use the 70/30 mix to keep at/top up to 300kpa for 3-5 days until I`m happy with the gas & head
I then reduce to 200kpa & serve there
Head & gas level stays constant
But I dont use straight CO2 or any rolling

 

[Logman]

Do you put it onto the gas at 300 straight out of the fermenter?

What about if you want to age the Stout for a few months?

:icon_cheers:

 

[Murdoch]

Yep, Gas it straight up as soon as kegged
Up to 300kpa if I want to start gassing (& drinking) straight away
Or if I want to age it I`ll wack it to 200kpa then when ready to drink I`ll check the gas level & increase up to 300kpa until its gassed which prob wont be as long if its been sitting at pressure & taken on some gas

At work we gas with 100% nitro at huge pressures (around 1700kpa) then serve at 200-250kpa on a 70/30 mix

 

[Logman]

Ok thanks Murdoch, got some ideas where I might be going wrong from that.

 

[beerbog]

Log, have you tried this new method yet? I've got an Irish Red coming off the ferment soon and I was wondering if I should give it a go? Cheers. B)

 

[Tony]

I used to run my system at 180 KPA.

I would filter the beer to keg cold, hook the gas (70/30) up the to the keg at pouring pressure with a non return valve on the line, and shake it for a minute. Let stand a minute and shake again.

I would repeat this a few times and hook it up and it would pour perfect first go.
I did get a slight increase in carb over the life of the keg but it never increased the head........ just how dense it was and the longer it sat, the better it was!