How much does adding rum affect ABV?

[BrewingTravisty]

Pretty much the question in the title, I have 4 gallons of smoked porter weighing in at 10%abv that I added 8 ounces of 35 proof (70%abv) spiced rum, that had been soaking in oak chips, to. Will this affect my ABV in anyway that I should list it on this beer? Or is it such a small amount that it doesn't really matter?

 

[whoaru99]

Probably not dead nutz on but I come up with roughly 10.9%.

EDIT: Actually 10.4%. Didn't catch the proof and % reversed in the first pass.

 

[hunter_le five]

35 proof (70%abv)

I think you got that backwards.

 

[wzd]

I get about .4% for the increase.

I assume it is backwards, as said above. So you are adding 8 ounces of 35% liquid to 512 ounces of 10% liquid. 8 ounces of the extra 25% gets spread across 520 (4*128 + 8) ounces, so 8*25/520 which equals .385

So 10.4%

 

[FloppyKnockers]

There's an algebra table for this. Google "mixture equation". I use it for whenever I prime with liqueur.

 

[whoaru99]

So 10.4%

I concur. In my initial run I didn't catch the proof and % being reversed.

 

[BrewingTravisty]

I concur. In my initial run I didn't catch the proof and % being reversed.

I get about .4% for the increase.

I assume it is backwards, as said above. So you are adding 8 ounces of 35% liquid to 512 ounces of 10% liquid. 8 ounces of the extra 25% gets spread across 520 (4*128 + 8) ounces, so 8*25/520 which equals .385

So 10.4%

Oops, you both are correct lol I went temporarily dyslexic xP thanks though! That's exactly what I was wondering. Not a huge difference, but a notable one I guess.

 

[BrewingTravisty]

I think you got that backwards.

Shhh you see nothing