ABV conversion - Home Brew Forums

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07-07-2012, 04:25 AM   #1
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ABV conversion

I normally have a caculator that does the work for me but I guess today it will not let me enter the values, and I forget the conversion formula.

Long story short my OG was 1.051 and my FG was 1.014
can anyone tell me the approx alcohol by volume [ABV]?

* a bit off topic but i do not taste any 'buttery popcorn'; so I guess I did the diacetyl rest correctly

07-07-2012, 04:29 AM   #2
passedpawn
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(og - fg ) * 133

4.9%
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07-07-2012, 04:37 AM   #3

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I keep reading that the formula is (OG - FG) * ~131... and I have seen 131.25 several times as the more accurate number.

I've also seen a couple of references to 129.

Using my 131.25 gives you an ABV of 4.86%... which is close enough to passedpawn's number as to not matter one whit.
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07-07-2012, 04:41 AM   #4
passedpawn
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Quote:
 Originally Posted by homebrewdad I keep reading that the formula is (OG - FG) * ~131... and I have seen 131.25 several times as the more accurate number. I've also seen a couple of references to 129. Using my 131.25 gives you an ABV of 4.86%... which is close enough to passedpawn's number as to not matter one whit.
Maybe it's 131 That was from memory. In fact, I know I've done that exact thing before (wrong multiplier). Sorry.

You know, I always just look at the OG to know what the final ABV is going to be. I.e., this one should be about 5.1% (1.051). Mathematically, if you assume 76% attenutation, my shortcut works perfectly.
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07-07-2012, 05:35 AM   #5
amandabab
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5 is a nice round #.

07-07-2012, 05:40 AM   #6

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Quote:
 Originally Posted by passedpawn Maybe it's 131 That was from memory. In fact, I know I've done that exact thing before (wrong multiplier). Sorry. You know, I always just look at the OG to know what the final ABV is going to be. I.e., this one should be about 5.1% (1.051). Mathematically, if you assume 76% attenutation, my shortcut works perfectly.
Very cool way to ballpark it.
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07-07-2012, 06:29 AM   #7
CBXBob

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1.054 -1.014=0.04 x 131=5.24 That the way I'ver been figuring it. just checked the FG on my watermelon Wheat 1.010 (extra sugar added) Started at 1.062-1.010=0.052X131=6.812, not bad for a wheat, Just tasted the sample, a little thin, but the watermelon flavor is nice