Attentuation, Someone Please Explain

[RLinNH]

I have looked this up in John Palmer's "How to Brew" book and in Ray Daniel's "Designing Great Beers" Book. Neither of which gives me a straightforward explanation of how to get an Apparent Attentuaion Rate. All I get is that if the OG is 1.040 and the FG is 1.010, the Apparent attentuation is 75%. How did they get to this?

[Bugeater]

I have looked this up in John Palmer's "How to Brew" book and in Ray Daniel's "Designing Great Beers" Book. Neither of which gives me a straightforward explanation of how to get an Apparent Attentuaion Rate. All I get is that if the OG is 1.040 and the FG is 1.010, the Apparent attentuation is 75%. How did they get to this?

Apparent attenuation = FG/OG

In this case 10/40 = 75%, just drop the 1 and the decimal point.

Wayne

[RLinNH]

With an OG of 1.040 and an FG of 1.010, I come up with an Apparent Attentuation rate of 77% using the Formula in Designing great Beers A= (OG-FG)/(OG-1)x100

[RLinNH]

Then what would the formulation look like to get the apparent attentuation of OG 1.061 and FG 1.026?

26/61=43%

???????????????????? Look about right?

[Bugeater]

Looks about right. Also looks way underattenuated. Probably pretty sweet isn't it?

Wayne

[RLinNH]

I KNEW I'd have problems with this batch!!! I knew I under Pitched. I was in a rush, wanted to Brew, grabbed a bag of Windsor Yeast and WLP 002, did a little 1 Pint starter, and went to town. Doesn't help either that both Carboys got down to about 58 degrees for a full day. DAMNIT!!!

OG 1.061 FG 1.021 I am not doing something right because I can't get a difinitive answer on that one...

[RLinNH]

Then what would the formulation look like to get the apparent attentuation of OG 1.061 and FG 1.026?

26/61=43%

???????????????????? Look about right?

Wrong. Found a site that explains everything and works out a formulation with you. That's how I learn. By doing an equation for myself. With the above OG and FG, I come up with 57% Apparent Attentuation


Here's the site http://hbd.org/uchima/tech/gravity.html

[BigNastyBrew]

Then what would the formulation look like to get the apparent attentuation of OG 1.061 and FG 1.026?

26/61=43%

???????????????????? Look about right?

No, that's not right.

With all respect, FG/OG gives you a number that you still have to subtract from 100 to get attenuation. 26/61=43, 100-43=57.

In ONE calculation: (61-26)/61=57

It's a percent change measurement.