Calculation of ABV

[NorwegianAle]

Hi, I need some help. I've been working on an excel sheet for calculating all aspects of my brewing (for fun/learning) and got a formula from Wikipedia for calculating ABV. This gives me roughly 4.4% for my last beer of SG 39 and FG 9. Beersmith tools tell me 4%. Which is correct? Why the difference?

 

[slym2none]

IDK why there is a difference, but a "fast & loose" way of calculating approximate ABV for me is, 8 gravity points = 1%.

Please note the term "fast & loose" and the word "approximate" in the above post.

 

[Biscuits]

Hi, I need some help. I've been working on an excel sheet for calculating all aspects of my brewing (for fun/learning) and got a formula from Wikipedia for calculating ABV. This gives me roughly 4.4% for my last beer of SG 39 and FG 9. Beersmith tools tell me 4%. Which is correct? Why the difference?

Maybe it is rounding? Also, does beersmith have a corrected value for temperature?

 

[j1n]

i just use an online calc.

brewersfriend says your ABV should be 3.94%

 

[1977Brewer]

i just use an online calc.

brewersfriend says your ABV should be 3.94%

That's what I got too.

The standard equation, and most commonly used one, is ABV = (og – fg) * 131.25. Should be easy to plug that one into your spreadsheet.

 

[OscarBrau]

The calculation I use is OG-FG x 1.31. So, 39-9=30 x1.31 = 39.3, or 3.93%

 

[ajdelange]

Hi, I need some help. I've been working on an excel sheet for calculating all aspects of my brewing (for fun/learning) and got a formula from Wikipedia for calculating ABV. This gives me roughly 4.4% for my last beer of SG 39 and FG 9. Beersmith tools tell me 4%. Which is correct?

Neither

Why the difference?

Formulas abound. None is completely accurate. Which formula did you take from Wikipedia? Brewing scientists use the Balling formula but you rarely see that mentioned except in texts books. I've put it in Wikipedia but the wiser editors have taken it out so I don't bother any more. It says

ABW = f1*(OE - TE)

where OE is the original extract in °P and TE is the true extract in °P. There is another formula

ABW = f2*(OE - AE) where AE is the apparent extract in °P. f1 and f2 are functions of OE. f2 is about 0.421 (IIRC) for nominal (13 °P) beers. Conversion to ABV is by

ABV = SG_Beer*ABW/SG_ethanol

 

[NorwegianAle]

Neither



Formulas abound. None is completely accurate. Which formula did you take from Wikipedia? Brewing scientists use the Balling formula but you rarely see that mentioned except in texts books. I've put it in Wikipedia but the wiser editors have taken it out so I don't bother any more. It says

ABW = f1*(OE - TE)

where OE is the original extract in °P and TE is the true extract in °P. There is another formula

ABW = f2*(OE - AE) where AE is the apparent extract in °P. f1 and f2 are functions of OE. f2 is about 0.421 (IIRC) for nominal (12 °P) beers. Conversion to ABV is by

ABV = SG_Beer*ABW/SG_ethanol

Wow. Thank you! Did you by any chance create beer back in the day? I will use this! Excellent!

 

[slym2none]

Did that Swede just call that Canadian ancient?

 

[GuldTuborg]

Wow. Thank you! Did you by any chance create beer back in the day? I will use this! Excellent!

What a strange thing to say.

 

[ajdelange]

Wow. Thank you! Did you by any chance create beer back in the day? I will use this! Excellent!

If you are going to use it you will want the values for f2

f2 = 0.39661 + 0.001709p + 0.000010788p^2

This represents a fit to the table in DeClerck

 

[ajdelange]

Did that Swede just call that Canadian ancient?

The guy calls himself Norwegian. I am American (but my great grandfather came here from Norway). As for the ancient, I'm afraid the shoe fits.

 

[slym2none]

The guy calls himself Norwegian. I am American (but my great grandfather came here from Norway). As for the ancient, I'm afraid the shoe fits.

All part of the joke, friend.

I know, I know... my sense of humour is really weird.

 

[NorwegianAle]

The guy calls himself Norwegian. I am American (but my great grandfather came here from Norway). As for the ancient, I'm afraid the shoe fits.

It was not my intention to be rude in any way. I was just trying to be funny and give credit for an excellent knowlege about calculations in brewing! It might be so that i use Expressions the wrong way, but I greatly appreciate the help and information. (and also i didn't manage to qoute both you and the guy you quoted...)

 

[slym2none]

We all have a weird, wonderful sense of humour!

 

[ajdelange]

Please be assured that no offense was taken. I have a weird sense of humor too!