FG to ABV conversion question - Home Brew Forums

 Home Brew Forums > FG to ABV conversion question

10-09-2008, 01:08 AM   #1
cbg96
Recipes

Aug 2008
Emerald City
Posts: 95

I looked around, got stumped in part because I didn't have all the info the various calculators needed, so here I am once again begging for mercy and guidance from Those Who Know Better.

I got a brand spanking new hydrometer last weekend. My second batch - Mystery Hops - is about ready to bottle having sat in the fermenter for three weeks. I draw a sample and float Mr. Hydro. My reading is 1.010.

Now the question.

I do NOT have an OG reading. I'm pretty confident this is a FG reading. Can anybody convert (or point me to a formula, etc) for converting this 1.010 reading to an ABV?

Thanks...
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Fermenter - Mystery Hops Winter Ale - bottled Dec. 20 - 1 lb Crystal 40l, 8lb LME, 8 ounces Karo (why not?), and 6 or 7 handfulls of hops

Drinking - SMaSH ale from Mystery Backyard Hops Version II with less hops and more fermentables - bottled Nov. 17

Deep Reserve - SMaSH ale from Mystery Backyard Hops (into the bottles on October 11); a winner & saving 5 bottles out

Deep Reserve - LHBS Recipe IPA - first effort Sept. 13, good stuff but undercarbed; saving 4 bottles

10-09-2008, 01:12 AM   #2
McKBrew

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Oct 2006
Hayden, Idaho
Posts: 8,204
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I'm hoping your hydrometer actually reads 1.010. (I'm sure it does). There is no way to figure approximate ABV unless you post your recipe and we can feed the data into brewing software and estimate the OG.
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10-09-2008, 02:40 AM   #3
WBC

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Jun 2007
La Puente, CA, California
Posts: 2,164
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Grimmy's Beer Math

Alcohol By Volume:

ABV = (Original Gravity - Final Gravity) x 131

Example:
OG -1.050 = 50 points and FG - 1.010 = 10 points

(50 - 10 = 40) x 131 = 5240/1000 = 5.24 ABV
(dividing by 1000 moves the decimal point).

Alcohol By Weight:

ABW = (0.79 x ABV) / Final Gravity
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WBC

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10-09-2008, 03:43 AM   #4
cbg96
Recipes

Aug 2008
Emerald City
Posts: 95

Original recipe is...:

6 pounds light LME
1 pound light DME
Wyeast 1056
Bunch of hops from the backyard vine
__________________
Fermenter - Mystery Hops Winter Ale - bottled Dec. 20 - 1 lb Crystal 40l, 8lb LME, 8 ounces Karo (why not?), and 6 or 7 handfulls of hops

Drinking - SMaSH ale from Mystery Backyard Hops Version II with less hops and more fermentables - bottled Nov. 17

Deep Reserve - SMaSH ale from Mystery Backyard Hops (into the bottles on October 11); a winner & saving 5 bottles out

Deep Reserve - LHBS Recipe IPA - first effort Sept. 13, good stuff but undercarbed; saving 4 bottles

10-09-2008, 03:55 AM   #5
jrakich87
Recipes

Oct 2008
Isla Vista, CA (Santa Barbara)
Posts: 142
Liked 2 Times on 2 Posts

Beer Alchemy gives that a 1.051. (1.051-1.010) X 131= 5.37%

...unless I'm leaving something out?

10-09-2008, 03:56 AM   #6
jrakich87
Recipes

Oct 2008
Isla Vista, CA (Santa Barbara)
Posts: 142
Liked 2 Times on 2 Posts

You should download the demo for BeerAlchemy... it's free for 30 days or 7 uses (I'm just keeping the program open on my Mac) and you can tweak recipes and techniques and get really accurate information.

10-09-2008, 06:06 PM   #7
cbg96
Recipes

Aug 2008
Emerald City
Posts: 95

"Beer Alchemy gives that a 1.051. (1.051-1.010) X 131= 5.37%"

Thanks for that. That's pretty close to the 5.2 the Beer Calculus site gave me by way of estimate. I likes muh beers with a little something to 'em, so a little higher ABV than expected is a nice bonus as far as I'm concerned.
__________________
Fermenter - Mystery Hops Winter Ale - bottled Dec. 20 - 1 lb Crystal 40l, 8lb LME, 8 ounces Karo (why not?), and 6 or 7 handfulls of hops

Drinking - SMaSH ale from Mystery Backyard Hops Version II with less hops and more fermentables - bottled Nov. 17

Deep Reserve - SMaSH ale from Mystery Backyard Hops (into the bottles on October 11); a winner & saving 5 bottles out

Deep Reserve - LHBS Recipe IPA - first effort Sept. 13, good stuff but undercarbed; saving 4 bottles

02-15-2012, 05:28 AM   #8
ChrisJPassarelli
Recipes

Nov 2011
Mountain View, CA
Posts: 81
Liked 4 Times on 4 Posts

Based on the values in Designing Great Beers, and a 5 gallon vol, I'm getting 5.8%, even (with an OG of 1.055ish). So hey, if anything, it might be even more peppy! Cheers, man. Should be a good subtle backbone for your homegrown hops.

02-15-2012, 05:42 AM   #9
passedpawn
Waste Allocation Load Lifter - Earth Class

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Apr 2009
☼ Clearwater, FL ☼
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oops
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02-15-2012, 06:39 AM   #10
day_trippr
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May 2011
Stow, MA
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Quote:
 Originally Posted by passedpawn oops
"Set the wayback machine for...2008!"

Forum noobs are so cute...

Cheers!