simple-stupid

Recipes 

So after two weeks in the primary I went to rack this batch to a carboy, and when I measured the gravity and wrote it down, I realized that I forgot to write down the starting gravity, even though I remember taking it.

So the question is.. what, if anything, can I do to find out ABV, mind you I don't really wanna buy some fancy kit and send it into white labs

Quick specs
OG: ? (I remember it being around 1.080 - 1.085)
FG: 1.026

Double_D

Recipes 

subtract your final gravity from the middle of your OG range. Then multiply by 131.

zachattack

Recipes 

Was it all grain or extract? With extract, assuming you had the correct final volume you can calculate the OG. If you're doing all grain, I'd just assume your average efficiency over the last few batches. Again, assuming you had the correct volume. But if you were brewing something in the 1.080 range, chances are your efficiency took a slight hit, I know mine does on bigger beers.

simple-stupid

Recipes 

it was extract, but I didn't follow the recipe exactly, I think I'll just have to be guesstimating pretty much

Thanks guys

Calder

Recipes 

If you post the recipe, someone will calculate it for you.

crunchydoc

Recipes 

or you can download a program like BrewR or beercalc for your smartphone and plug in your formulae. I have found BrewR to be remarkably accurate! within a 0.2% for ABV. it will provide you OG, projected FG and ABV based on those values.