From: mark@verdix.com (Mark Lundquist)
Newsgroups: rec.crafts.brewing
Subject: Re: Your brewing expertise needed
Date: 8 Jan 93 19:40:00 GMT
Article-I.D.: verdix.9502
Distribution: usa
Organization: Verdix Western Operations, Aloha  OR

In article <1993Jan8.001447.1044@digi.lonestar.org> sagard@digi.lonestar.org (Steve Agard) writes:

>    2. How does CO2 in the headspace "protect" against infection?

Hmmm...you mean in the fermenter, right?  It's not the CO2 per se that
protects the beer, it's the pressure gradient between the fermenter
and the surrounding air -- the fermenter wants to blow out gas, which
keeps outside air from getting in.

>	Are all beer-infecting organisms (other than wild yeasts) aerobic?

I know that there are anaerobic beer spoilers, I believe acetobacter
is one.

>    4. I made a starter, but not far enough ahead of time, and used this
>       to pitch into 60 degree wort about 1-1/2 hours after starting the
>       starter. At that point I pitched the total contents of the starter.
>       Was this appropriate? Under ideal conditions, what do you recommend
>       as the normal process?
>    5. Is a starter worth the trouble?

Yes.

The idea is to increase the "pitching rate" (amount of yeast) so as to
reduce the "lag time" before active fermentation begins.  (You don't
want to overpitch, but with just a 1-2 qt. starter you don't have to
worry about that.)  I don't believe that you're trying to pitch yeast
that has somehow been "awakened" out of dormancy and is now in its
"reproductive" phase (maybe some yeast expert out there confirm or
correct me when I say this is an old wives's tale), because the yeast
is going to go into respiration as soon as it hits the wort anyway.
If you wait until the starter has fermented out, then the yeast volume will
be maxxed out, their glycogen levels will be built up and they are
ready to rock!  (Disclaimer: this is a theory that I have read about and
which seems to make sense, but I have not done any experiments myself.
In other words, it may be another old wives' tale!)

You can make up a couple of gallons of starter wort and can it in
Mason jars (Dave Miller's book explains how to do this).  This saves
you a lot of trouble.  A couple of days before I brew I just pop a jar
of starter wort and pitch.  You can pitch yeast from wherever -- a
Wyeast pouch, yeast from a previous ferment saved in a bottle, or even
the dregs from a bottle of homebrew or other bottle-conditioned beer.
(You probably only want to reculture to the second generation
though).

>    7. During primary fermentation, I let wort warm from 60 to ~72 for 30
>       hours, and then brought it back to 60 degrees. What might the effects
>       of this be under the best and worst circumstances?

There won't be any bad effects over this temperature range.  This
range of variance would have some effect on ester production, which is
a matter of taste and appropriateness to style.

>    8. If I use priming sugar in my secondary (as was posted earlier today?)
>       can I let it sit for an hour (instead of the poster's 10 minutes) and
>       achieve virtually sediment-free beer? Is an hour too long? If so, if
>       I brought the temp back down to 60, and slowed the yeast could I get
>       away with this? Can I get away with this without temperature mods?

The yeast is going to work on the priming sugars, and it's going to
make CO2.  You want that CO2 in your beer, not blowing off to where
your beer will never see it again!  Siphoning into a priming vessel
isn't that big of a deal, especially if you're going to jack around
with the temperature to try to avoid it (which I don't think would
really work anyway).  Then again, maybe there wouldn't be enough
fermentation in the first hr. to make a difference, or maybe you could
compensate by adding more priming sugar.  You could always experiment
around with it and see how it works.  I'd forget about the "cool to 60'F"
part though.

>   10. Do you think there might be a different "ideal" water content for
>       Ales and Lagers?

Certainly for different styles there would be ideal water chemistries,
but I don't think it generalizes to "ale vs. lager".

>   12. Do you see a benefit to introducing (i.e., floating) additional
>       CO2 or N to the open secondary or bottling containers to further
>       reduce the likelihood of airborne contamination? Note, I'm not
>       talking about pressurized transfer or artificial carbonation.

Sounds like way overkill to me.  I believe most infections introduced at
bottling time are the result of improper sanitization of bottles or
equipment.


Happy brewing!
Newsgroups: rec.crafts.brewing