attenuation question - Home Brew Forums

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05-23-2010, 12:31 PM   #1
redfox
Recipes

Jan 2010
SW PA
Posts: 19

if the OG = 1.065 and the yeast strain has an attenuation of 70-76 percent, what SHOULD the FG be?

I know I should be able to figure this out, but...it's early here!

Thanks!

05-23-2010, 12:55 PM   #2
danielinva
Recipes

Jun 2008
Henrico, VA
Posts: 259
Liked 1 Times on 1 Posts

FG = OG-((OG-1)*Attenuation)
so
FG=1.065 - (.065*.75) = 1.065-.049 = 1.016

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05-23-2010, 01:10 PM   #3
redfox
Recipes

Jan 2010
SW PA
Posts: 19

thank you, danielinva!

yes, that makes sense.

05-23-2010, 02:01 PM   #4
homebrewer_99

Recipes

Feb 2005
Atkinson (near the Quad Cities), IL
Posts: 17,796
Liked 136 Times on 102 Posts

For many yeasts 75% is within the attenuation range.

For a quick computation I divide the OG by 4 and the answer is the FG.

Of course, danielinva's process is more precise.
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05-23-2010, 04:26 PM   #5
david_42

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Oct 2005
Oak Grove, Oregon, USA
Posts: 25,599
Liked 158 Times on 148 Posts

Quote:
 Of course, danielinva's process is more precise.
Although you really should calculate the range, not just one value.

There's always ways to make brewing more complicated.
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05-23-2010, 04:36 PM   #6
TipsyDragon
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Mar 2009
California
Posts: 2,607
Liked 25 Times on 23 Posts

your FG should be between 1.020 and 1.015. don't be alarmed if its a couple points outside this range.