Promash % Alc vs. Onebeer.net - Home Brew Forums

 Home Brew Forums > Promash % Alc vs. Onebeer.net

05-05-2011, 02:02 AM   #1
ryandlf
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Mar 2011
Charlotte, NC
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What gives? I must be using the Promash calculator wrong. I have a brix refractometer and my OG was 12 and FG 6. Promash gives me an ABV of 2.90 and the Onebeer.net calculator gives me an ABV of 5.26. What gives!?!
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05-05-2011, 02:12 AM   #2
Yooper
Ale's What Cures You!

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Did you convert the Brix reading of 6 for a final gravity? Refractometers can't be used once fermentation has begun without some calculations to account for the alcohol. A 6 is a very high FG, so I would hope you haven't bottled until you take a hydrometer reading!

Anyway, the easiest way to figure ABV is to convert your brix readings to SG and then do some simple math. (OG-FG) x 131= ABV.

So, in this case, if 6 is really the FG (and I hope that's wrong!), you have:

(1.048-1.024) x 131= 3.1% ABV
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05-05-2011, 04:11 AM   #3
ryandlf
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Charlotte, NC
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Oh ok. I didn't realize that the alcohol was messing with the refractometer readings. According to this calculator my actual FG is 1.009 giving my an ABV of roughly 4.8% which is much better I've been trying to figure out why my ferments are coming in so high since I got my new toy

Does anyone know if promash has a built in calculator to compensate for fermenting beer like that other calculator I posted?
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Fermenting/Conditioning:
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05-05-2011, 01:53 PM   #4
ryandlf
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Mar 2011
Charlotte, NC
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Bump
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05-05-2011, 06:57 PM   #5
ryandlf
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Mar 2011
Charlotte, NC
Posts: 257
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Figured it out...go to the Utilities menu at the top, then Refractometer, then Specific Gravity During Fermentation. For anyone that might find this thread in the future
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Fermenting/Conditioning:
Cecile's Secret IPA
Midnight Blackout Dark IPA

On-Tap:
Highland Oatmeal Porter Clone
Jungle Love APA