Commercial gas

Mashtun

When i worked in a pub a couple of years back there was always at least two different gas supplies. The lagers & cider were carbonated of a green bottle which i think was CO2 and nothing else but stand to be corrected. The other supply was for guinness. I presume the different bottle was used to supply a nitro mix for the guinness.

Anyway, i was speaking to a publican recently and he said there is only one gas bottle needed nowadays provided by BOC and this provides gas for every beer in the house.

Anybody know how this works? where does the nitro for the stout come from?

I'm interested in doin something with a commercial keg at some stage and equally if i could get a commercial gas cylinder then i'd be sorted for quite some time. I'm sure i could come to some understanding with the local if I brought back the bottles!

Fuzzy Clam

Assuming it hasn't changed in the last few years, this is how it works. Larger/Ale/ciders are usually 40-50% Co2, the remainder is N2. Stout is 20-25% Co2.
Small outlets may have separate cylinders for Stouts and Lagers. These are all premixed. Green cylinders but different labels.
Larger outlets use premixed (25% Co2) gas for Stout and some of this gas is also blended with pure Co2 to provide the higher 50% mix for Lagers etc.
The largest pubs, which I think your Publican is referring to, use a machine to generate nitrogen. This is stored in large cylinders which do not get changed by BOC. There are 2 blenders in the machine to mix this N2 with the supplied Co2.

Co2 is in black cylinders. Mixed gas in green(ish) bottles.

If you want to set up your own keg you need premix. 25 or 30% usually, and a regulator set to about 35 or 36 psi. It may be possible to get a premix bottle with a attached reg that will be good for 2 or 3 kegs max.
Whatever you do, do not use a mix greater than 30% for Stout unless you know what your doing. Lower than 50% for lagers is ok, i.e Stout gas.

I'm interested in doin something with a commercial keg at some stage and equally if i could get a commercial gas cylinder then i'd be sorted for quite some time. I'm sure i could come to some understanding with the local if I brought back the bottles!

You need a regulator, not cheap but I might know where to get one. If you're well in with your local publican, he might let you have a cylinder with a few kegs of gas left in it. Green cylinder only though!

Mashtun

Fuzzy Clam wrote: »

Assuming it hasn't changed in the last few years, this is how it works.

That's the thing i think it has. I haven't worked n a pub since 2007 but when i did it had the mix of cylinders that you just described. It seems in the mean time things have changed. I've seen the, now much larger, gas cylinders he was talking about. They're the same height as meself!

Anyway just want to clarify. Stout is gassed of a 25% CO2 75% N2 mix. This is supplied at 35psi. Largers Ales & Ciders use a 50/50 split roughly speaking. Is this supplied at the same pressure?

Fuzzy Clam

Mashtun wrote: »

That's the thing i think it has. I haven't worked n a pub since 2007 but when i did it had the mix of cylinders that you just described. It seems in the mean time things have changed. I've seen the, now much larger, gas cylinders he was talking about. They're the same height as meself!

Anyway just want to clarify. Stout is gassed of a 25% CO2 75% N2 mix. This is supplied at 35psi. Largers Ales & Ciders use a 50/50 split roughly speaking. Is this supplied at the same pressure?

No I don't believe it has changed. The cylinders vary depending on the outlet. As I said, there are 3 different systems, the result is the same though. BOC try to deliver the larger Co2 cylinders because it's cheaper to do so. Some small pubs still only use premix which is available in small or large green cylinders. It varies from outlet to outlet.


The pressures are usually the same. About 35psi at the keg for Guinness products. Other brands may use different mixes and pressures.

Do not connect the cylinder directly to a keg without a proper regulator!