# How Much Beer Will A 16g Co2 Bulb Serve?



## Bribie G (15/11/09)

I bought a keg charger for the case swap and a pack of 5 16g bulbs. It's not a cheap option but absolutely perfect for the few times a year I want it for. Apart from the case swaps we've got a couple of family events coming up over the holidays, a 21st and a BBQ barge trip so portable beer on tap will be the ducks nuts. Just wondering, anyone with this system, how much beer will one bulb push? I came back from the case swap with a quarter of a keg left, there's still gas in the bulb but I don't know if it's bulb one or two. I passed out at some point in the evening and came home with only 3 bulbs out of the pack, however I might have lost one when I fell over in the bushes in the dark whilst.... ok that's another thread :lol:


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## Peteoz77 (15/11/09)

I have found that it usually goes into cartridge 3 before the tank empties, and the last 3-4 pints use a LOT of a charger. Not sure if yould finish with two or not on an 18 litre keg.


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## Bribie G (15/11/09)

Peteoz77 said:


> I have found that it usually goes into cartridge 3 before the tank empties, and the last 3-4 pints use a LOT of a charger. Not sure if yould finish with two or not on an 18 litre keg.



Yup I used a similar system with pressure barrels in the UK and as you say, the more empty the barrel gets the 'law of diminishing returns' kicks in. I came home with about a quarter of the keg left and put it back in the kegerator. I guess, therefore, that the guys must have swapped in the second bulb which I seem to recall I had left near the mega-esky at the case swap.


:icon_offtopic: I wonder if there's any way to use a car foot pump via a gas disconnect? I remember commercial kegs of UK beer being served that way at dances and socials when I was a teenager.


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## Peteoz77 (15/11/09)

We always just used a hand pump, but without being driven by C02, they get oxidised, as you are filling the empty space with outside air (oxygen)


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## Bribie G (15/11/09)

Yes the foot or hand pump would only suitable for dispensing a keg in one hit for a party or BBQ. In the UK, the old Hull brewery (that the famous Ringwood yeast originally came from) had an air pressure system for serving in their pubs but the beer and the air were separated by a membrane. Sort of a mega cask wine system, not unlike a very large version of the polypins you can get in the UK.

Anyway, getting off topic


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## Tony M (15/11/09)

16 grams of CO2 fills 8 litres of space at normal temp and pressure and a lot less at 4 or 5C, so Peteoz would be right and if the beer wants to take up more gas, you could use more.


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## jonocarroll (16/11/09)

I was just about to post a new thread with a similar question...

I've just had a full trial run of my new portable setup (to be revealed in another thread in the coming days) and I've found that I don't get the 'It'll push a 19L keg' results I had been spruiked upon purchase.

I've also been curious - to the people who use these little cartridges, do you leave the QD on the post all the time, or do you take the charger/QD off? I can't help but think that the QD need not be attached to the post all the time, since no pressure is being added until you pull the trigger. Hopefully, no pressure escapes when the trigger is not pressed, but is that actually the case?

I think I ended up using 2 cartridges to push about 1 1/2 kegs, but they were pressurised fully first.


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## Zwickel (16/11/09)

a normal lager or pilsener beer requires 5g of CO2 per liter.

In case the beer is optimal carbonated in the first place, you only have to substitute the loss of volume in the vessel, that means likewise 5g per liter.

Cheers


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## Bribie G (16/11/09)

With the charger that I bought, it works on a trigger and no gas escapes until you squeeze it. I'll be doing the 21st Birthday thingo in about 3 weeks time so that's the earliest I can do a full test, I'll bump the thread then.


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## jbirbeck (16/11/09)

Used my set up yesterday - full keg down over the day. The beer was unfortunately over carbed to begin with BUT it used 2 12g chargers to dispense the whole keg. Had thought about getting the 16g bulbs but they were significantly more expensive when I looked, 12g have treated me fine.

I've found if the beer isn't carbed up properly to begin with dispensing it can use a LOT more bulbs. I haven't found the sweet spot yet.


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## Bribie G (16/11/09)

Not rubbishing the sponsors, who have to make a living, but I've come across a Supplier in Australia that sells the 16g cartridges for around $1.70 each in lots of 10, or around $1.30 each in a carton buy of 300 freight free. Hmmmmm.
Probably not a suitable item for a bulk buy however.


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## jonocarroll (16/11/09)

Zwickel said:


> a normal lager or pilsener beer requires 5g of CO2 per liter.
> 
> In case the beer is optimal carbonated in the first place, you only have to substitute the loss of volume in the vessel, that means likewise 5g per liter.
> 
> Cheers


I hadn't thought of it in those terms - makes sense I guess, but if the numbers are correct and you can indeed keep the head pressure up, then the last pint of pilsner would be pushed by the 6th 16g cartridge.

My response question would be - how much pressure is in the 16g cartridges? Can they even add pressure to a keg when half full? I presume that when you push the trigger, you connect the keg to the cartridge so they are a single system. Unless the pressure in the cartridge is greater than that of the keg, there will be no 'topping up'.

Maybe I do need a sodastream setup...


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## MHB (16/11/09)

Funnily enough I had someone in the shop asking the same question, went looking for a calculator to check the result, *found this one*.
Turns out that 16g of CO2 should pressurise a 20L keg to just over 40 kPa at about 3 Co
If you want to play with the numbers the Formula Weight of CO2 is 44 so Number of Moles is about 0.364 (#Mol=Mass (g)/ Formula Weight)
Handy little calculator

MHB


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