On Mon, Jun 06, 2005 at 09:45:08PM +0200, Thorkild Nielsen wrote:
> Det er ikke køle-tiden, der er den farlige, men
> det man foretager sig, fx. at staa og bevaege en
> chiller op og ned. Det er potentielt farligt men
> med en solid gang gaer som Heikki skriver saa
> gaar det godt alligevel.
> Hvis det var tiden, der var farlig ville daasemad
> og juice paa kartoner ikke kunne holde sig i
> aarevis.
I agree with you in theory - but not in practice.
Your example of conserved food does not quite apply - such tins are
hermetically closed while the cooling happens, so no airborne
micro-organisms can get into them. Even when you cool the beer directly
in the pot with the lid on (as I often do), or in the fermenting bucket,
the connection is not airtight. And when the beer cools, it gets a few
percent smaller. This would produce quite an underpressure in the pot,
if it was not leaking somewhere. And that's where the bugs can sneak in.
Another detail is that the wort should get enough oxygen for the yeast
to use in the beginning of the fermentation. This is usually done by
allowing it access to air - and airborne bacteria.
Therefore I believe it is practically impossible to keep the wort
completely free of bacteria and other harmful bugs. What one can do is
to shorten the time those bugs can multiply and fill the pot, before the
yeast has got such a hold of it that it will out-compete them all. To me
this means shortest possible cooling time, and a hefty and ative yeast
starter. It is not that a slow cooling always leads to an infected beer,
but I see it as a risk, and an unnecessary one at that.
Luckily, most of the time things go well, and
it will be beer anyway
-H
--
Heikki Levanto "In Murphy We Turst" heikki (at) lsd (dot) dk
