From the HBD Archive
From: Darryl Richman <darryl@ism780c.isc.com>
Subject: re: What is your exctract efficiency?
Date: 1989-02-07 15:22:55 GMT

In the Feb 06 digest,
hpfcla!hpcea!hplabs!rutgers!boulder.colorado.edu!akelei!crispy!dwight (Dwight Melcher)
writes about "What is your extract efficiency?"
"So, the crux of the question is this: most books seem to imply that
"ones extract efficiency should be in the 80-90% range, while my extract
"efficiency is always around 70%.

Part of the problem here is the 100% extract numbers. I've got Noonan, and
he suggests one set of numbers; I've just bought Dave Miller's new book,
and he's got another (higher) set. I'd like to see some brewing industry
book that actually discusses this and gives a baseline.

I don't usually worry about percentage efficiency for this reason. I do look
at my extract per pound of grist per gallon of water. As my technique has
become more refined, the numbers keep creeping up. For recipe formation,
I used to just lump everything but any black grains together and figure
1.030 per pound per gallon. I watch all of the grain recipes that go by
in zymurgy, and it is rare to see anyone getting above about 27. There are
occasional recipes that claim above 1.038 when you work it out, but I figure
that they have a typo somewhere. Lately I've been getting 1.032 out of beers
with no black grains.

"Here are some general areas that probably affect ones extract efficiency
"and my humble observations about my techniques:
"
" * Grain Grinding - I use a Corona mill. Perhaps I'm not grinding the
" grains finely enough? From what I've seen of other grists, my grind
" appears OK.

A balance you must achieve is grinding as finely as you can and still being
able to sparge in a reasonable amount of time. Our shop bought a small
professional grain grinder last year and I think it does a wonderful job.
Before that, a club project built one out of a motor, two rolers from a
store's checkout-counter conveyor belt that had been junked, and some sheet
metal for a hopper; it also worked well after two passes.

" * Mashing: I always get a negative iodine test within 15-30 minutes of
" reaching saccharification temperatures, so I'm confident conversion
" is complete before I sparge.

Don't you find it interesting that most books (Dave Line, Greg Noonan, and now
Dave Miller) mention to check for conversion after an hour? I, too, get quick
conversions. Sometimes I have gotten a negative response within 10 minutes
of achieving saccharification temperatures.

" * Sparging: I suspect this may have the greatest influence on the final
" extract efficiency. My sparging technique follows Noonan's
" book reasonably closely, and my lauter-tun is a "zapap" style
" (that is, two 5 gallon buckets, one inside the other).
" Any hints or tips in this area would be appreciated.

I have built one of the "hacksawed copper tubing manifold inside a picnic
cooler" types of lauter tuns. I recycle about 2 gallons of wort before it runs
clear. At first I ended sparging when the outflow ceased to have any sweet
flavor left. Then I got Noonan's book and he recommends stopping when the
wort reaches 1.008 SG (after adjusting for 60F). This turned out to be further
than I had been sparging. Another book (lost to my mind at the moment)
suggested stopping before the pH went above 6.0; this turns out to be beyond
SG 1.008. So now I don't worry and collect enough for the boil and topping up
during the boil. This may be different for you depending on your water.
You ARE treating your sparge water, aren't you?

"So, if everybody else is getting extract efficiencies in the 70% range,
"I'll just relax and assume these other sources are a little off.
"Otherwise, I'd be interested in hearing your techniques that lead to
"a higher extract efficiency.

Using the numbers from Noonan's Table 20 as 100% efficiency values, I'm getting
pretty close to 100% (I get a 1.032 from a 90% 2 row and English Pale mash).
But I've seen other values quote 1.036-38 as 100%, and so I figure I'm getting
in the mid-80% area. But once again, contradictory numbers make me wary,
and I'd really like to find a brewing industry source for these.

Good luck, and may your mashes clear quickly,

--Darryl Richman

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