### Author Topic: Calculating Beer ABV w. Booze Additions  (Read 858 times)

#### Megary

• Senior Brewmaster
• Posts: 1163
##### Calculating Beer ABV w. Booze Additions
« on: March 26, 2020, 07:23:28 am »
My thinking is that if I add a spirit (tequila, rum, maybe both  ...etc.) to a finished beer at packaging, the new ABV would be a balancing equation of volumes and ABV's:
(Vol1*ABV1 + Vol2*ABV2 +Vol3*ABV3 etc.) / (Vol1+Vol2+Vol3 etc.)

Or is there more to it than that?  And if there is more to it than that is it really worth the extra effort in figuring it out?

#### kramerog

• Brewmaster General
• Posts: 2262
##### Re: Calculating Beer ABV w. Booze Additions
« Reply #1 on: March 26, 2020, 09:02:11 am »
Your equation should work fine. There could be subtle changes in volume when mixing, but the equation will be close enough.

#### Iliff Ave

• Official Poobah of No Life. (I Got Ban Hammered by Drew)
• Posts: 4508
##### Re: Calculating Beer ABV w. Booze Additions
« Reply #2 on: March 26, 2020, 09:07:57 am »
I think it should be as simple as a weighted average calculation. I added 4 oz of rum to a smaller batch and it bumped up the ABV by 0.2% according to weighted average.
On Tap/Bottled: IPL, Adjunct Vienna, Golden Stout, Honey Lager
Fermenting: IPA
Up Next: mexi lager, Germerican pale ale

#### Megary

• Senior Brewmaster
• Posts: 1163
##### Re: Calculating Beer ABV w. Booze Additions
« Reply #3 on: March 26, 2020, 09:29:22 am »
I think it should be as simple as a weighted average calculation. I added 4 oz of rum to a smaller batch and it bumped up the ABV by 0.2% according to weighted average.

Weighted Average!  Yes, that's what they call it!  I think that's what my equation represents, but I'm way too far removed from algebra to remember the proper terminology.

Thanks all.

#### Iliff Ave

• Official Poobah of No Life. (I Got Ban Hammered by Drew)
• Posts: 4508
##### Re: Calculating Beer ABV w. Booze Additions
« Reply #4 on: March 26, 2020, 11:14:05 am »
I think it should be as simple as a weighted average calculation. I added 4 oz of rum to a smaller batch and it bumped up the ABV by 0.2% according to weighted average.

Weighted Average!  Yes, that's what they call it!  I think that's what my equation represents, but I'm way too far removed from algebra to remember the proper terminology.

Thanks all.

I hear ya. I couldn't remember either although it seemed so simple. I'm sure I'll forget next time I go to do it...
On Tap/Bottled: IPL, Adjunct Vienna, Golden Stout, Honey Lager
Fermenting: IPA
Up Next: mexi lager, Germerican pale ale