Help with an ABV question please...

[eric_618]

I'm absolutely dumb when it comes to math. I just don't get it and my brain shuts down. It's why I was a Psychology major!

Anyway, I'm trying to determine ABV of an IPA I'm about to bottle. OG was 1.071 at approximately 70 degrees, and FG is 1.014 at 63.

It's a Ferocious IPA extract kit from Midwest, but I altered the recipe a decent amount in terms of hop additions and adding the malt 50/50 at boil and with 15 minutes to go. I also added a pound of honey at flameout. I used White Labs WLP001.

Thanks MUCH in advance!

 

[gpack]

Should be around 7.5% ABV.

 

[gpack]

Sorry, with temp correction.

1.072 to 1.014

Will give you right at 7.7% ABV

 

[progmac]

(og-fg)*129

 

[eric_618]

Awesome. Thank you very much!

 

[eric_618]

(og-fg)*129

Is that, in layman's terms, OG minus FG times 129? I'm sorry, but I am that stupid when it comes to math. If so, does that account for temperature correction? Thanks!

 

[yso191]

So from one bad-at-math psych major to another, buy Beersmith software. It does all the calculating for you!

Steve

 

[GrogNerd]

Is that, in layman's terms, OG minus FG times 129? I'm sorry, but I am that stupid when it comes to math. If so, does that account for temperature correction? Thanks!

does not account for temperature correction... do the correction THEN input OG and FG into the formula

and you thought you would never need algebra after high school

 

[progmac]

Is that, in layman's terms, OG minus FG times 129? I'm sorry, but I am that stupid when it comes to math. If so, does that account for temperature correction? Thanks!

exactly. (1.071-1.014) * 129 = 7.35%. the 129 is a constant. some people use 131 instead.

there are some different methods, one of which gpack must be using since his number is a little different.

the "no, seriously, i hate math" quick-and-dirty method that requires no calculating whatsoever is to just take the last 3 digits of your OG and throw in a decimal.

so 1.071 is about 7.1% or 1.110 is about 11.0% ABV

this super-quick-and-dirty method does not consider the fermentability of the wort, so it might underestimate the ABV of a dryer beer (eg with sugar/honey additions or a low mash temp) or overestimate the ABV of a fuller bodied beer (eg with a high mash temp or maltodextrin addition)

 

[rayfound]

I have seen 131 as the constant, never the 129. Weird.

Interestingly, when I use this formula vs. using what beersmith calculates, beersmith gives me a higher ABV than the basic formula

 

[eric_618]

So from one bad-at-math psych major to another, buy Beersmith software. It does all the calculating for you!

Steve

Android has a Beersmith Lite in the Play Store for $3.99. I'm not sure the differences between the full and lite versions, but I just purchased regardless. Thank You!!!

 

[GenIke]

Google abv calculator.