From the HBD Archive
From: lbr@gatech.edu
Subject: re: What is your exctract efficiency?
Date: 1989-02-09 18:49:12 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%.

In the Feb 07 digest, Darryl Richman <darryl@ism780c.isc.com> replies

>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've got Noonan, Miller's first book, and Line's Big Book. Is there any
reason for me to buy Miller's new book? I'd have to mail order it; I
can't leaf through it in the store to see if I like it. )-:

> 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.... Lately I've been getting 1.032 out of beers
> with no dark grain.

I get 1.030. After reading the initial posting I got out Noonan's book
and figured that this was .65 pounds per pound of malt: 65%. I hadn't
used Noonan's method because I was happy using Alan Tobey's method
(see Fall '81 zymurgy) that figures SG per pound per gallon. He says
28-32, which I get. I also didn't use Noonan's method because he
prefers professional brewering measures like Balling and pounds of
extract per gallon. But mostly (pet peeve) his formulas are written
like IRS forms. What brain dead editor thinks that persons who buy
a book this technical can't deal with simple formulas expressed in
algebraic terms? He gives a formula for computing the volume of a
cylinder that's 8 or so lines long! ("Multiply line 3 by 3.14" etc.)

> "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.

I use a grain mill. All the books say this is a compromise.

> " * 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.

Me too. Though of course I leave it longer to get that maltose I need.
Miller's first book said don't use this test since husks can react and give
a false positive reading. I do the test (it's trivial to do) but I
consider it worthless. :-)

> " * 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).

> 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?

Exactly what I do. I often stop sparging sooner that I "should." So
what--my time is far more important that achieving a slightly more
efficient extract. Noonan implies that the cooler method that serves
you and me well is not as good as one where the filter bed is deep. But
it really is nice. My first method was Miller's first book grain bag
method. A real pain by comparison.

> "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.

Did I compute this wrong? I computed 1.030 as .65 lb extract / 1 lb malt, which
is far lower than the .80 Noonan says I should get. My reading of his
book is that you're getting in the high 60s, nowhere near 80.

Noonan's book reads like it came from industry sources. Their extracts have
got to be better than ours: better equipment and procedures, and more
incentive, too. I don't really care if I throw a little sugar out with
the spent grain.

- Len Reed

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