Building A Cpbf Without O2 Purge.

[Florian]

But why wouldn't there be any air/oxygen left, isn't the point of partial pressures that the CO2 will be added to the existing air that is in the bottle instead of displacing it? (genuine interest here - not trying to say your wrong as i'm possibly way off the mark)

I'm not smart enough to understand Dalton's law and partial pressures, but my common sense tells me that when I blow enough Co2 long enough into a bottle that it will eventually displace the air that was there before. After all, that's how I always assumed commercial counter pressure fillers worked. Am I wrong?

 

[Nick JD]

I like watching this kinda shit. Probably a throwback to those old Sesame Street factory tours - wicked.

There also a bonus that the soundtrack sounds like it was written by the Chinese Mike Oldfield. That's either a good or a bad thing depending on your sense of humour with regard to music.



EDIT 2:20 for the CPBFing. They don't go much faster than me - they do however fill a hundred at once.

 

[drsmurto]

Venting/purging your bottle with CO2 will remove all the O2, I use the same principle at work with kegs connected to N2 that get flushed via the diptube. Kegs are used as an inert atmosphere storage system, not for beer. I measure the amount of O2 in the keg down to 1 ppb with an oxydot that is fitted to the keg lid.

The difference is that i close the gas relief valve with a positive pressure of N2 so that i maintain the atmosphere of N2.

You can't do that and cap your beer at the same time so the time between filling and capping will mean some O2 gets in to the beer if there is any headspace (foam counts as headspace albeit with lower gas volume than no foam). Filling to the brim with beer will overcome that although the lid is curved so there will be some headspace in the bottle (tip it upside down and see the bubble rise to the top).

 

[tallie]

It's there, it's just sitting on a blanket of CO2 because O2 is lighter.

Nick, the fermenation would've halted on a commercially available beer as no company would want their yeasts reused/pilfered by another brewing company. The beers a lot of us tend to make still have the yeast active, hence the slow buildup over months/years of that protective CO2 blanket. :icon_cheers:

The "CO2 heavier than O2 blanket effect" is an oversimplification - there is no clear separation between the gases, even in a closed system (lookup Brownian motion).

And your second comment ignores every commercial bottle conditioned beer; Coopers being an obvious example! It's more that (most) commercial beers are shipped after their fermentation is known to be finished.

Cheers,
tallie