On Tue, 03 Apr 2007 20:36:02 GMT, <beowulf_is_not_here@hotmail.com> wrote:[color=blue][color=green]
>> MDixon (used to be a regular on here) did some experiments a while ago
>> along those lines. IIRC, he found that yeast would remain active up until
>> around 45PSI or so, before they shut down and ceased activity. Can a bottle
>> take that much pressure? I don't know for sure, but it sounds high. I
>> would guess that the bottle would blow before the yeast stopped?[/color]
>
> I know from an episode of Myth Busters that 3L plastic soda bottles blow
> up around 90 PSI. Is it reasonable to expect a glass bottle to hold
> more or less?
>
> I don't know. Glass is thicker, but also more brittle. IIRC, the
> source for my original statement was one of the Charlie Papazian books.
> So he may have been speculating at that point.[/color]

Yeah, those PET soda bottles can take a surprising amount of pressure. IMO,
much more than a typical glass beer bottle. Typically, glass becomes "iffy"
at anything higher than around 4 volumes of carbonation... whatever PSI that
works out to.

I could be entirely wrong here, but atmospheric is what... 14PSI? So 4
volumes of carbonation should be something like 4X that, or 56PSI? In that
case... maybe the bottles could take 45PSI and survive.

I've heard lots of theories over the years regarding how (or even if) the
amount of headspace effects carbonation. I've never really seen anything
that has definitively answered the question though. Lots of speculation,
but nothing really concrete.

It does make some sense that an initial burst of pressure build up would
halt yeast activity but... Does the pressure really build up that quickly?
Carbonation by the yeast is generally a relatively slow process. Also, one
would assume that after the initial burst, as the CO2 dissolves into the
beer, that the yeast would resume when the pressure drops back down.


John.