Keg2bottle ????

[normell]

Plan on putting some beer into bottles from a gassed keg using a counter filler.
How long will the beer be good, 1 - 2 weeks???

Normell

[Guest]

Never done it, but I imagine that so long as your bottle is airtight it'll last for years.

[JAZZA]

I once made a brew at a micro brewery in Perth and it had been force carbonated and was cold when it came time to bottle it.

drank most of it at christmas and what was left put in the garage.

one day they started exploding, spoke to the brewery and they said that they need to be refridgerated once they have been bottled or it goes off

dont know how true that is?

[Oliver]

Normell,

Did you mean how long before you can drink it?

I would have thought immediately. If it's carbonated and drinkable out of the keg, I would have thought it would be OK from the bottle without waiting.

I reckon the beer should last a while in the bottles (although probably not indefinitely like a bottle-conditioned beer).

Cheers,

Oliver

[grabman]

Correct me if I'm wrong, which is frequently however I would think that what Jazza is on about is the reverse of when you force-condition your brew in a keg with CO2.

That is the colder the liquid to more gas it will absorb at a faster rate; therefore if the liquid is allowed to warm up it will release the gas. If in a glass the CO2 is released into air around us, however if in bottle is releasd from liquid and fills head space to a point where pressure in bottle is too great and bottle explodes.

As I said correct me if I'm wrong but to my way of thinking it makes sense.

[Oliver]

Grab,

Wouldn't that mean that commercial brewers would have problems, too?

They'd either have to bottle cold and risk the bottles exploding when they warmed, or bottle warm and have the beer undercarbonated when it's cold.

Or is there a happy medium? Or is the pressure when the beer warms not enough to make the bottles explode?

I'm sure someone will correct me on this!

Oliver

[grabman]

mmmmmm now I'm confused, it made sense when I posted the first time, but in hindsight Oliver you have a point. Maybe there is a happy medium temp or their gas setup is different!

But I have heard as Jazza said that beer from micro-breweries like U-Brew-It has to be kept cold or it will go off!

might be time to experiment, will need to get counter filler first to ensure pressure is right though.

[Dogger Dan]

You know the big woosh and spillage you get when you open a warm beer. Then think of the little phst you get when it is cold as ice. That is what Grab is on a bout and he is bang on the mark.

So they carbonate cold as you can do it faster with less pressure and stick it in bottles that are designed to with stand twice the pressure limit generated by being warm.

Back in the 70's Coke switched to a 2 Litre bottle that had the nasty habit of blowing up in peoples faces because of this same issue. They solved it by using a thicker walled bottle.

Dogger

[Oliver]

So a beer that blows up when it gets warm is either overcarbonated or in a bottle that's not designed to take the pressure (or has a flaw)?

i.e. the brew shop was telling porkies when they said that after bottling, their beers had to be kept refrigerated. It was either their process or dodgy bottles causing the problem?

Oliver

[Dogger Dan]

Carbonation in a bottle is an equilibrium thing. The colder the temp the more CO2 can be in the beer and then the less in the headspace. As it warms up, less CO2 can be dissolved in the beer so you would have to increase the pressure of the CO2 to maintain the same volume of dissolved CO2. As you can't do that in the bottle, the CO2 leaves solution as the temperature increases and sits in the headspace increasing the pressure there. This increase in pressure will lead to the bottle breaking if the bottle is weak

Ok, so then what. If a beer is designeds to be drank at say 2 deg C and have say 12 percent CO2 dissolved in it then the beer should be carbonated to that level at 2 deg C

If you store it at 30 deg C, the equilibrium will shift such that there is more gas and less dissolved and this gas is in the headspace, building pressure. Pressure overcomes the bottle integrity and it fails. Ironicly, if you tried the beer you would find it flat even though you blew the bottle apart.

Dogger

[grabman]

Thanks Dogger, I thought I was on right track! If I remember my physics right it's related to Combined Gas Law based on Boyles Law where;

P1*V1 /T1 = P2*V2 / T2

Where relationship between pressure, volume and Temp is balanced so if one variable changes the others have to adjust to keep balance. Hence in our bottles V (volume) can't change as bottle is sealed. Hence if T (temp) changes then P (pressure) in bottle changes to keep system in balance.
For a better explanation http://members.aol.com/profchm/comb_gas.html

Geez that was a stretch at 7.30 in the morning, but amazing what you remember at times!

[r.magnay]

shit!!! are you blokes home brewers or bloody rocket scientists? I havn't even had a drink today and my head is spinning! But then I spose I'm just a dusty old country boy.

[Dogger Dan]

Ross,

All sorts of things to ponder while you gaze lovingly at the amber necter

Dogger

[BPJ]

Dogger, going back to my High School days (20 years ago - It feels as bad as it sounds)

If i have say 1000 molecules of CO2 (normally measured in Moles) in a given space of say 1 cm3 it would have a pressure of x.

If I have 1000 molecules of O2 (or any other gas) in the same volume I would still have a pressure of x

If I combined both gases in the one space they would still only have a pressure of x and not 2x. THis is because the gas molecules are only worried about "getting away" frome the same type of molecules. (the same way smells spread)

Is that right?

If so when filling from a keg the headspace would be mostly air (20% CO2) so when it warms up the increase in pressure would not be as bad as expected.

[Dogger Dan]

Yeh,

Apples and oranges though, its the equilibrium that you need to look at

Andy

[Whitty]

Then think of the little phst you get when it is cold as ice.

Dogger

Don't you love that noise.........

[Whitty]

Then think of the little phst you get when it is cold as ice.

Dogger

Don't you love that noise.........

[grabman]

Help, I'm seeing double again

Must be too much beer, if there is such a thing!

[Dogger Dan]

Yeh,

but it really is a great sound.

Dogger