New Giveaway - Wort Monster Conical Fermenter!

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

01-30-2011, 08:29 PM   #1
BrewNow
Feedback Score: 0 reviews
Recipes

Join Date: Sep 2010
Posts: 175
 Help with OG Calculation (Math Deficient)

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, 08:41 PM   #2
Hex23
Feedback Score: 0 reviews
Recipes

Join Date: Jun 2010
Location: Illinois, Lake County
Posts: 857
Liked 42 Times on 42 Posts
Likes Given: 45

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

__________________

01-30-2011, 08:43 PM   #3
CPooley4
Feedback Score: 0 reviews
Recipes

Join Date: Apr 2009
Location: Cottage Grove, Wisconsin
Posts: 393
Liked 13 Times on 8 Posts

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

__________________
CP's Brew Workbook

If you're considering buying brewing software do yourself a favor and download my Brew Chart/Workbook first. You may not need to spend that money.

I like beer math!

01-30-2011, 08:45 PM   #4
Zamial
Feedback Score: 0 reviews
Recipes

Join Date: Apr 2010
Location: WI
Posts: 3,177
Liked 165 Times on 147 Posts
Likes Given: 7

The above math looks good to me and if not it is prob close enough for beer!

http://www.rooftopbrew.net/abv.php

__________________
“I'm not drunk, I'm from Wisconsin.”
We have been out drinking your state since 1848!

01-30-2011, 08:59 PM   #5
BrewNow
Feedback Score: 0 reviews
Recipes

Join Date: Sep 2010
Posts: 175

Awesome! Thanks for the help.

__________________