Help with OG Calculation (Math Deficient) - Home Brew Forums

 Home Brew Forums > Help with OG Calculation (Math Deficient)

01-30-2011, 09:29 PM   #1
BrewNow
Recipes

Sep 2010
Posts: 187

Due to the size of my primary kettle (#1) I needed to dump some of the sparge into a second kettle. So my brew day ended with the 2 brew kettles at different volumes and starting gravities:

Kettle 1 - 3.5 gallons @ 1.081
Kettle 2 - 1.5 gallons @ 1.042

The entire wort was all tossed in a 5 gallon glass carboy. Without pulling a sample, can anyone calculate the actual SG of this beer? Or at least ballpark it?

I was shooting for 1.066 with this beer.

01-30-2011, 09:41 PM   #2
Hex23
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Jun 2010
Illinois, Lake County
Posts: 990
Liked 61 Times on 59 Posts

It should be a weighted average: 81*(3.5/5) + 42*(1.5/5) = 69 (1.069)

01-30-2011, 09:43 PM   #3
CPooley4
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Apr 2009
Cottage Grove, Wisconsin
Posts: 393
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81 x 3.5 = 283.5
42 x 1.5 = 63
283.5 + 63 = 346.5
346.5 / 5 = 69.3
69.3 = 1.069

cp
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01-30-2011, 09:45 PM   #4
Zamial

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Apr 2010
WI
Posts: 3,183
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The above math looks good to me and if not it is prob close enough for beer!

http://www.rooftopbrew.net/abv.php
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01-30-2011, 09:59 PM   #5
BrewNow
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Sep 2010