From the HBD Archive
From: lbr@gatech.edu
Subject: Re: yeast, hops, coolers
Date: 1989-04-06 22:39:22 GMT

In #119 Pete Soper <soper@maxzilla.encore.com> writes:
> A pitching rate frequently seen in descriptions of commercial
> brewing practices is 5% by volume. That's a quart of yeast per 5 gallons
> of wort. That's *yeast*, not yeast+starter wort.

Where are you getting this number? Noonan and Miller say commercial
pitching rates are .6 to 1.25 fl. oz. per gallon. Five percent sounds
more like krausen, which is fermenting wort. Three to six fluid ounces
is more yeast than most homebrewers provide, but is a far cry from a
quart. Noonan describes various problems associated with overpitching--
though most homebrewers don't overpitch it can be done.

> I have one of those BrewCo caps which together with an upside-down
> carboy allows collecting the yeast from a primary fermentation. I
> haven't used it yet. Partly because it is gardening time here, but also
> because I'm afraid of not being able to maintain proper sanitation.
> But if I've got a quart of yeast paste, a speck of dust won't have the
> same impact, since by definition I won't have significant growth of yeast
> (or bacteria) before pitching it again. Hmm.

I have one of those. It worked nicely the first two times, but the third
time I used it the yeast/trub drain valve leaked and bubbled air into the
beer. The beer didn't spoil, but when I noticed this I had real trouble
not worrying. I never did repitch drained yeast from this thing because
the timing was never right. I like the BrewCap for the following reasons:
1) you can get the last bit of the nasty trub out without racking.
2) you can control how long the beer sits on the yeast, and how much
yeast there is in the carboy. This should help in diacytyl reduction.
3) bottling is far easier using gravity directly than through a siphon.

I'll probably try to modify the drain mechanism to ensure that it doesn't
leak air--obviously I can't tolerate unsterile air getting into my fermenting
wort.

David Miller's yeast methods (written up in zymurgy last year) work nicely for
me. I have had good success reculturing yeast from bottled beer. I
also use his method for canning wort to use as a starter. If I can get
2-4 batches from a $4.25 pack of yeast, I'm happy. I don't want to
set up a microbiology lab at home.

> But the thing I'm still curious about is whether you fellow Homebrew
> Digesters ferment your starters out fully before pitching them?

Me too. Sometimes I do, sometimes I don't. And what about temperature?
I've seen recommendations to use 75 degF in the lager starter, but I'm
concerned about shocking the yeast and mutations when adding them to
the 50 deg. wort. It seems more reasonable to ferment the starter at
the same temperature it will be pitched, or no more that 5 deg higher.

---

Happy birthday to me! My wife gave me an old refrigerator. She got it
for $2.20 at a sealed bid auction run by the county schools. It works
fine, and holds up to 52 degF with no modifications. I asked her why
she bid $2.20 instead of two dollars, and she said she wanted to outbid
any cheapskate who'd only go $2.00. It's no thing of beauty, but I
hope it can help in the creation of some beautiful things.

Len Reed
.!gatech!holos0!lbr
holos0!lbr@gatech.edu

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