---

	FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
		Rob Gardner, Digest Coordinator

Contents:
  Wort Aerating (lbr)
  dryhopping (Algis R Korzonas +1 312 979 8583)
  Citrus fruits in beer. (Algis R Korzonas +1 312 979 8583)
  gravity and temparature (Algis R Korzonas +1 312 979 8583)

Send submissions to homebrew%hpfcmr at hplabs.hp.com
Send requests to homebrew-request%hpfcmr at hplabs.hp.com


----------------------------------------------------------------------

Date: Wed, 8 Feb 89 13:36:56 EST
From: lbr at gatech.edu
Subject: Wort Aerating

jhersh at rdrc.rip.edu writes:

> I don't think that commercial 
> brewers aerate their wort to the extent that homebrewers do or rely upon
> the wort to serve as a media for yeast reproduction to the extent that
> homebrewers do.

Second part is certainly true.  Homebrewers too often pitch a packet of
dry yeast (yuck!) and wait for it to build up in the wort.  Pros pitch
thick slurry or actively fermenting starter.  The pros may aerate less,
but I think they do aerate some (with sterile filtered air, of course).

> Anaerobic fermentation is a different process and will also result in yeast
> reproduction but to a lesser degree. I believe that the different fermentation
> pathway yields fewer of the nasty alcohol by products that aerobic 
> fermentation generates.

> Much of this information has been garnered from collections of papers by
> European breweries such as BASS and Carlsberg which are present here in
> our library....

Have you read Noonan's book "Brewing Lager Beer"?  It is by far the most
technical homebrew book I've seen, though of course it doesn't compare
with professional brewing literature.  He indicates that some of the
products you mention, such as fusel alcohol, come from *inadequate*
aeration for the wort, and that aerobic fermentation must occur before
the anaerobic fermentation starts.  Anaerobic fermentation then takes
place at a lower temperature after some of the yeast nutrients have been
depleted.  He recommends high pitching rates, well in excess of what most
beginning homebrewers use, so I don't think that having enough yeast
obviates the need for oxygen.

I don't think you're right that adding a lot of yeast to oxygen-poor
wort is a good way to start fermentation, but I'm no expert.  Please
send me some paper references if you get the chance.  I get down
to Georgia Tech's library sometimes and they should carry major
technical journals.

Many homebrewers introduce too much oxygen after primary fermentation,
especially during racking and bottling.  This is bad.  But everything
I've ever read says that the yeast need oxygen when the fermentation
starts.

Postscript: Georgia Tech rejected e-mail I tried to send to rdrc.rip.edu

Len Reed
gatech!holos0!lbr

Return to table of contents


Date: Wed, 8 Feb 89 12:54:42 -0600
From: hplabs!uiucdcs!iwtsf!korz (Algis R Korzonas +1 312 979 8583)
Subject: dryhopping

Hello--
Regarding sanitization of hops for dry-hopping, two possible
methods come to my mind: 1) a germicidal lamp 2) steam.
Are these viable methods?  I haven't used either so I can't
vouch for them.
Al.

Return to table of contents


Date: Wed, 8 Feb 89 13:16:11 -0600
From: hplabs!uiucdcs!iwtsf!korz (Algis R Korzonas +1 312 979 8583)
Subject: Citrus fruits in beer.

Hello again--
Here's a little bit of history regarding citrus fruits in beer:

1) Lemon slices in weizen (or weiss - wheat or "white" beer)
originated during the BR era (before refrigerators).  Weizen
used to spoil more easily (maybe due to lower hopping rates)
and sour.  Weizen drinkers used to put lemon in their beer
to make it drinkable.  Since the invention of the refridgerator,
the tradition continues in some circles, but _TRUE_ weizen
drinkers skip the lemon (this theory was reinforced on my
trip through Bavaria last year around Faching (the German equivalent
of Mardi Gras).

2) Lime slices in Mexican beer originated when they began using
cans for distributing beer.  The back room of a bar in rural
Mexico can provide plenty of dust and dirt to settle on the
top of the can.  Bottles are fine - take off the cap and
pour, but what's a patron to do with the top of a can?
Hmmm, let's see... what can I use to clean off the top
of this can?  How about one of these lime wedges set on the
bar for the tequilla?  Yes -- this is how the limes got near
the beer, but the locals always threw the dirt-encrusted lime
away.  It took a half-blitzed Madison Avenue-type to misunderstand
the lime into the beer.

Personally, I have tried only Corona, Carta Blanca, and Tecate, and
I find all of them poor excuses for beer.  As we all know, 98% of
your beer is water, so, garbage-in-garbage-out.

Al.

Return to table of contents


Date: Wed, 8 Feb 89 13:18:54 -0600
From: hplabs!uiucdcs!iwtsf!korz (Algis R Korzonas +1 312 979 8583)
Subject: gravity and temparature

Could someone please post a formula or table for
converting specific gravity measurements at different
temperatures to specific gravity at 60 F?
Thanks.
Al.

Return to table of contents

---