ABV Calculations

When I use the Northern Brewer refractometer calculator, I get one number for ABV. When I use Brewers Friend calculator, I get another. The difference is only 0.3 but I am wondering why they are different. I am guessing it has to do with the Brix to Gravity during and after fermentation converter for the refractometer. Any thoughts?

Did you use the refractometer calculator?

If so, what did you set the Wort Correction Factor to in Brewer’s Friend?

I will use my last batch as an example. The OG was 1.038 by my refractometer. I always calibrate before any batch and it has never needed adjustment. After fermentation had ended, I took another refractometer reading in Brix which was 4.8. Using the Brix to Gravity during and after fermentation converter, it gave me a FG of 1.007. So now that I have the OG and FG in SG units I use these two calculators.

Approximate ABV and Original Gravity from current Brix and Gravity converter

http://www.northernbrewer.com/learn/res ... alculator/

Alcohol By Volume ABV Calculator

http://www.brewersfriend.com/abv-calculator/

Like I said. Only a 0.3 difference but I’m still curious.

There is a link off the Brewer’s friend calculator page you should look at:

http://www.brewersfriend.com/2011/06/16 ... r-updated/

I don’t know if the info on that will explain the difference you are seeing, but it does do a much more accurate job of predicting alcohol levels for higher gravity beers.

[quote=“rebuiltcellars”]There is a link off the Brewer’s friend calculator page you should look at:

http://www.brewersfriend.com/2011/06/16 ... r-updated/

I don’t know if the info on that will explain the difference you are seeing, but it does do a much more accurate job of predicting alcohol levels for higher gravity beers.[/quote]
Thanks for the link. After reading, I think the best thing to do is do a hydrometer reading comparison on my next few batches.