Gas In The Line

[Wortgames]

I think I've got around 2m of 4mm ID line. I'd start with about 3 metres and work down from there.

I haven't used mixed gas, so I can't comment with any degree of accuracy, but my feeling is that it would be slow/difficult/impossible to carbonate with. IE, it may be fine for dispensing precarbonated beer, but it would probably take ages to carbonate flat beer.

Nitrogen DOES dissolve into beer, but it doesn't like to stay there, and it doesn't oxidise it. Divers experience 'the bends' because of dissolved nitrogen in the blood forming bubbles as the pressure decreases. Nitrogen forms smaller bubbles than CO2, hence the creamy head on a Guinness.

There is also an effect in gases, where each gas occupies its own space at its own pressure. I'm not sure what it's called but I think it's covered in Boyle's law. Basically, gas can enter a vessel even if the vessel is under pressure, as long as it is under pressure from a different gas. In other words, a semi-permeable plastic container, under pressure from CO2, will still have oxygen seeping in - because the oxygen only sees other oxygen, and will therefore move to places where there is less oxygen pressure. Confused yet?

What this means is that the beer would still try to reach equilibrium, except that now you'd have two gases trying to equalise instead of one. It is probably a much slower process (which suits a pub dispensing a pre-carbonated keg within a week or two) but I think it would still mean changes occurring over time.

I can't see any advantage to using a nitrogen/CO2 mix (other than for creamy heads), but I can see potential issues.

 

[Tony]

Great explination wortgames.

I have to aree with pistolpaatch.

I run a fill comercial setup in my fridge with a 50 liter keg and all the fittings ect.

I find that the tirst 1/4 of a schooner is over gassed after it has sat for the day when i pout a beer. I currently pour a 2 second spurt in an old mug and tip it and then fill the glass.

I spoke to my father about this (he has worked setting up kegs in pubs for 20 years, he rembers spearing the old 18 gallon kegs) and he said "CO2 will do that, you need beer gas boy"

I asked what the hell that was and he said it was a muxture of CO2 and nitrogen that stoped the gas going into solution during the time the beer was still in the line.

I have a 2.5 to 2 meter lenght of god knows what size line, i guess ita about 3 or 4 mm internal, the megaswill linesman kindly equiped me with it, and with the reg set at a constant 75 to 80 kpa i get a perfect beer.

like i said, the first couplke of mouthfulls are wasted then i ger a glass with a 3/8 inch head and fine bubbles holding a white film on the beer till the last mouthfull, even if i leave it a while.

I think i will give BOC a ring tomorow and ask about the "beer gas"

cheers

 

[Ross]

I think i will give BOC a ring tomorow and ask about the "beer gas"

cheers

[post="95935"][/post]​

Don't ask for "beergas" This is just CO2 & you'll be charged a premium. The nitro/CO2 mix has a different name...

cheers Ross

 

[Guest Lurker]

In my pub days, sometimes we used to increase the gas pressure to stop foaming as this holds the CO2 in solution. Then, beer gas became available, which has a mixture of CO2 and nitrogen, so we moved to that. The nitrogen is inert so doesn't get absorbed by the beer. All it does is act like a soft drink lid i.e. keeps the pressure on so the CO2 doesn't escape from the beer.

[post="95919"][/post]​

As WG points out above, gases are funny things. CO2 in solution in beer reponds to the partial pressure of CO2 in the environment/headspace above it. Filling the head space with N2 doesnt make a lid, because the CO2 doesnt "see" the N2 pressure, and will happily leave the beer until balanced by the resulting CO2 pressure.

There is a good article from Mr Wizard in a BYO magazine on getting pure nitrogen into beer. The best method is a stone in the keg, and a slightly open release valve so the nitrogen is continually bubbling through the beer.

 

[Agarn]

As I'm just setting up a keg system I don't profess to be an expert or anything, however i found the following sites to be useful for telling me how to design a balanced system / carbonate:

Draft system line balancing

A metric carbonation chart can be found here (along with bulk priming info which probably not be of much use now you've got kegs)

carbonation table (& bulk priming info)

Cheers

Crozdog

[post="95780"][/post]​

All I can say is thank the beer gods that my system is now working properly!!
This is all too confusing, however the simple explaination really helped.
Had two pints out of it yesterday that made me go weak at the knees!!

Thanks once again for all your assistance.

 

[SteveSA]

I think i will give BOC a ring tomorow and ask about the "beer gas"

cheers

[post="95935"][/post]​

Don't ask for "beergas" This is just CO2 & you'll be charged a premium. The nitro/CO2 mix has a different name...

cheers Ross

[post="95944"][/post]​

Cellarmix

 

[Black Dog Brewery]

Wortgames, thanks for the explanation.

I would like peoples thoughts on my setup and what I should do / expect to happen.
I have a temprite that I am about to use for the first time. According to what I have read I should chill the beer prior to carbonating it. As I dont have a beer fridge I was going to run the flat beer through the temprite into the keg I intend to dispense from and then force carbonate.
To the question - Will the co2 drop back out of the keg as it re warms to room temp after force carbonation or cause problems when pouring.

Cheers BDB

 

[Guest Lurker]

Wortgames, thanks for the explanation.

I would like peoples thoughts on my setup and what I should do / expect to happen.
I have a temprite that I am about to use for the first time. According to what I have read I should chill the beer prior to carbonating it. As I dont have a beer fridge I was going to run the flat beer through the temprite into the keg I intend to dispense from and then force carbonate.
To the question - Will the co2 drop back out of the keg as it re warms to room temp after force carbonation or cause problems when pouring.

Cheers BDB

[post="96040"][/post]​

The second commandment issued from the mountain by WG was "Dont screw with the thermostat". In other words keep the beer at the same temp. So if you are going to serve from a warm keg I would keep it at the same amount of warmness all the time. I suspect trying to pour from a keg which has just been gassed and is slowly warming from fridge to room temperature (and CO2 is frantically leaving the beer and increasing the pressure in the headspace in response) would be a nightmare. It should be possible to gas warm beer, just takes a lot more pressure than if it was cold.

 

[tangent]

just a quick note about working with gases like CO2.
Anyone working in a winery would be very aware of this:

"Asphyxiation is the greatest danger associated with nitrogen and other inert gases since they do not support life and are capable of reducing oxygen concentration to very low levels through displacement and dilution. Most accidents occur due to workers entering vessels that are connected to a nitrogen supply and that have not been properly checked for oxygen concentration before entry. Fatalities have occurred due to workers simply leaning into a vessel with an oxygen depleted atmosphere to inspect it. Complete entry is not necessary for a very serious or fatal accident to occur. Inhalation of an oxygen depleted atmosphere can cause a person to immediately lose consciousness with no warning, such as dizziness, and die from asphyxiation. Tragically, there have been many examples of fellow workers going to the aid of victims and becoming victims themselves because they were not aware of the cause of the initial incident."

 

[crozdog]

View attachment co2_and_keg_balancing.xlsSorry if some of you found the info I posted not so easy to grasp or use, I agree it isn't too user friendly. As most of the hard info on this topic is of US origin, it quickly becomes difficult to use the data presented especially as the wrong units are given.

Hopefully I have now overcome this for AHB members by using the info on those sites to create the attached spreadsheet to calculate line lengths and required co2 pressures IN METRIC!

The results can then be used as the starting point to building a balanced keg co2 system. In addition the tables can be used as a reference for the pressures required by differert beer styles at different levels of carbonation and temperature.

I hope that some members will find the attached spreadsheet useful. It only requires the following steps to be performed:

1. determining the pouring temperature
2. determining the level of carbonation required (look up a table)
3. measure the tap height
4. entering this data into the attached spreadsheet

Note, this workbook has involved numerous conversions eg psi to kpa, degrees F to degrees C, not to mention psi/foot to KPA/m! it has not been quality checked by anyone but me :excl: - there may be some errors - all feedback welcome.

Cheers
Crozdog

 

[PistolPatch]

Have just rung BOC to work out what CO2/N2 content all the different gases are. Will put the info up in a new post which will be titled, " CO2, Beer Gas, Multimix, CellarMix - Content and Prices"

Hope putting it up as a new post is the correct thing to do???

 

[PistolPatch]

Three things...

Re the temprite: In my ag college days, we used to have heaps of warm 18 gallon kegs chilled through a temprite. We'd just pick them up warm from the pub. Hopefully you'll drink it in one sitting if through a temprite, so you need a higher pressure than normal. The numbers 10, 12 and 15psi ring a bell to me regarding pressure but this was 20 years ago so I can't remember what was right! Sorry! But use jugs for the first litre or so before you fiddle with the pressure. I assume pubs still do the keg hire with temprite thing so maybe a phone call to a pub will give you a starting point?

Re Wastage and Foam: When I worked with Matilda Bay (20 yrs ago!!!) and we introduced all the boutique beers, we had huge wastage initially as we used to clean the lines every night and then put the kegs on the next morning. This meant that in the morning, we had a beer line full of gas so when we'd put the keg on, the beer would basically explode up the line as there was no resistance. The wastage was seriously 2-3 litres per keg and it would take ten or fifteen minutes to get a single keg pouring right - ridiculous! After seeing this I couldn't believe it and so ended up filling the line with water before attaching the keg. The beer would just chase the water up the line and poured perfectly first beer. This became standard practice and I would imagine still is.

I'd think that the same problem would occur with homebrewing even though the line is only a few metres. So, after all this writing, what I'm saying, is can you possibly fill the line with water before you attach it to the keg. (I'm not too sure how these corny systems work yet as mine doesn't arrive till the end of the week - a BrewBratt system. Hope it's good!)

Re Beer Line Length - Wortgames, thank you. I will go for 3 metres!

 

[Fingerlickin_B]

After seeing this I couldn't believe it and so ended up filling the line with water before attaching the keg. The beer would just chase the water up the line and poured perfectly first beer. This became standard practice and I would imagine still is.

Yep, the big clubs with literally hundreds of meters of beer line do this.

In fact, they also do it in reversean hour or two before closing the night preceding cleaning day they disconnect the keg and put a contraption called a water cup onto the coupler that introduces water instead of beer, so almost all the beer still sitting in the lines gets dispensed rather than wasted and once it gets watery at the tap they stop serving from that line and simply serve stubbies until after the cleaning process.

As you can imagine, in a very large football club (or similar) a lot of beer could be lost, should these procedures not be implemented.

PZ.

 

[Sparky]

crozdog....

Thanks a million - the spreadsheet looks very useful & is far easier to work with than my pages of calculations that I have alongside me.

Cheers for putting the time & effort in & posting it here.

tangent....

Have spent the last 3 days on a work course learning Confined Space & Hazardous Atmosphere Entry. Agree with you 100%.

Were shown examples of exactly what you have stated. One incident, 3 dead, 2 dead after entering a space to attend to initial victim.

 

[PistolPatch]

Ah Fingerlickin! You've brought back memories! Yep, we had to do this 20 years ago it as we were the first pubs to have more than 2 or 3 beers on tap. In fact, just roughy we had about 6 going to 3 to 5 banks depending on whether it was busy or not. Every night, we had to estimate how many more beers we'd sell through a line as each night we'd run water through the lines (the cleanliness of the operation was first class). You can imagine the abuse we'd get though when a certain line ran out just before closing!

We were also the first in WA to introduce having a head served on a beer. A standard drink was 10ozs, so we served our beer in 12oz glasses - 10 ozs of beer and 2 ozs of head. The complaints we used to receive though! It took ages for people to realise that we weren't ripping them off! Fond memories!

 

[Wortgames]

There are regularly punch-ups in Holland, started when English tourists get served a beer with too much head.

The traditional English pint only has about 5-10mm of head on it, whereas the Dutch like a good third of the glass to be head.

To make matters worse, I suspect some Dutch bar staff deliberately stretch the boundaries for their own amusement...

 

[Fingerlickin_B]

To make matters worse, I suspect some Dutch bar staff deliberately stretch the boundaries for their own amusement...

[post="96318"][/post]​

ROFL :lol:

 

[tangent]

my brother served beers in a soccer clubrooms and the ethnic patrons would go ape if he didn't pour a big fluffy head on the beers.

back to the issue - Andale cut my gun's line themselves but I suspect it's the perfect length for pouring commercial lagers. It's flexmaster 8mm x 5mm.
My IPA seems to be a bit too malty and unless it's very mildly carbonated, it just seems to pour too fast and too much foam. If I leave the pressure down really low (~20kpa) it pours ok but really slow, but is losing too much carbonation in the ale. I'm wondering if I should get 2 guns and have another line about 4 meters long. Then use the long line for foamy ales and the shorter for lighter lagers?
Or am I grasping this the wrong way round?