From the HBD Archive
From: gca!smith@uunet.UU.NET (Steven Smith)
Subject: *BIG* Blow-off
Date: 1990-04-05 13:55:08 GMT

David
I always use a filled carboy as a primary fermenter, and almost always get
some amount of blow-off. I typically get a quart to a half-gallon, I have
never quite gotten a gallon out. Sounds like a pretty vigorous fermentation
you've got going there.

Examination of the blown-off liquid generally makes me pretty happy that
it is being removed from the beer I drink. A lot of the hop residue and various
oils tends to come out. As an experiment you may want to try a small taste
of the blow-off just once. (Only if there is no bleach or other sanitizer in
it).

Now as to topping off, no, I have never tried this. One thing I typically
do with ales is to skip secondary altogether. I find that fermentation is
typically done in one to two weeks, and I go directly to bottling from there.
With the vigorous fermetation you have I would not be surprised if your
fermention is done soon.

If you do rack and plan to leave it in the secondary a while my opinion
is that the air space is no problem as long as fermentation is still going
when you rack. The yeast will quickly produce a "blanket" layer of CO2 that
insulate the surface of the beer from oxygen.

If you do top off I have one word of caution. A friend of mine was once
trying to add an oak flavor to his beer. He boiled oak chips for a half hour,
discarded the chips and added the water to his mostly fermented brew and
replaced the air lock. As the water cooled it decreased the pressure in the
carboy, which sucked his airlock water back into his brew. As he had used
bleach in his airlock solution he was quite bummed and poured out the lot.

One last note on the topic of losing brew through blow off. I finally went
out and purchased two new carboys, one 7 gal and one 6 gal. I now start
my lagers in the 7 gal. carboy (just proportionally increase the recipes).
After primary I rack to the 6 gal. carboy. Between blow-off and discarding
the sludge at the bottom of the primary I usually completely fill the 6 gal.
secondary.

This technique has been very successful, with the benefit that I usually
get 2 1/2 cases per brew. The same approach could be used with a 6 gal.
primary and 5 gal. secondary.

Good luck,
Steve

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