Hydrometer interpretation

[GLWIII]

Using beersmith trial version to concoct my first brew it tells me to expect a FG of 1.017 (OG 1.065) with an ABV of 6.31 for an IPA I am making. Having checked my secondary after 8 days my reading is 1.016, but the ABV on the hydromerter lines up with around 3-4% abv. I'm not sure why the disparity exists? Any ideas?

 

[blacklab]

that's not what that scale means. your ABV is your OG-FG x 131. I think that's % balling, which has no relation. I don't have a hydro in front of me to confirm what that % is, but I do know that it's not your ABV.

 

[Bobby_M]

I think the potential ABV scale on hydrometers only apply when the beer is done fermenting and it's a rough estimate based on a 75% attenuation. This doesn't work at any intermediate stage of fermentation and 75% attenuation is just a guess. Beersmith is doing the math between OG and FG and it's exactly right.

 

[Arneba28]

Yeah thats the %balling. I think you can use that also but you have to take the OG with the balling scale also. Then Subtract your final balling reading from your original balling reading and that gives you abv. The standard gravity scale is much more accurate.

 

[BREW N QUE]

I believe the % alcohol scale is for wine. You take this reading before fermentation and it tells you the potential alcohol if your finishing gravity lines up with the zero on the potential alcohol scale. I think?

 

[pcrawford]

To use the %ABV scale you subtract the number %ABV (before fermentation) from the number %ABV (after fermentation) and that gives to ABV%.

8% wort - 2% FG = 6% final ABV %

 

[Funkenjaeger]

To use the %ABV scale you subtract the number %ABV (before fermentation) from the number %ABV (after fermentation) and that gives to ABV%.

8% wort - 2% FG = 6% final ABV %

+1.

I sort of wish they'd leave that scale OFF the hydrometers because obviously it often generates confusion, and it's so easy to calculate ABV from OG/FG readings anyway...