measuring abv

[jhlu87]

So I know you can calculate the abv by knowing the OG and FG. However, I think I screwed up my OG reading so what I want to do is measure the abv at the end and use that and the FG to work out the OG. Is there a cheap and easy way to measure the abv of the finished product?

 

[unionrdr]

there are a couple of different formulas you have to use to get somewhat accurate. I use the cooper's one;(OG-FG)/7.46 +.5=approximate ABV%. The "+.5" is added to account for the priming sugar.

 

[cvstrat]

You could estimate the OG by whatever the recipe says it should be, or if you want to be totally sure you could try the following:


Ralph Snel ([email protected]) wrote: A quite simple way that will give accuracy up to 0.1% is to boil off all the alcohol and substitute by water. This means boiling down to less than a third of the original volume in most cases, it's not that hard to smell if there are alcohols in the vapour. Fill with water so you have your original volume and take the difference in gravity, then look up alcohol content in the table:
SG Alcohol SG Alcohol SG Alcohol
diff. vol % diff. vol % diff. vol %
0 0.00 10 7.18 20 16.00
1 0.64 11 7.98 21 17.00
2 1.30 12 8.80 22 18.00
3 1.98 13 9.65 23 19.00
4 2.68 14 10.51 24 20.00
5 3.39 15 11.40 25 21.00
6 4.11 16 12.30 26 22.00
7 4.85 17 13.20
8 5.61 18 14.10
9 6.39 19 15.10
10 7.18 20 16.00

 

[malkore]

The equipment to directly measure alcohol content in the finished product isn't available to homebrewers.

You MUST use OG (or an estimate) and the FG to find it.

Or, ship your beer to a lab and have it tested.

 

[lumpher]

So I know you can calculate the abv by knowing the OG and FG. However, I think I screwed up my OG reading so what I want to do is measure the abv at the end and use that and the FG to work out the OG. Is there a cheap and easy way to measure the abv of the finished product?

the abv at the end is the fg. same thing. you can go with the estimate from beersmith or some other program, but there is no way to be accurate if you don't get the starting gravity (og)

 

[Hockeyhunter99]

you can take the points from each of you fermentables. they should be in ppg and found one the labels. when you have figured out your OG, take the difference between OG-FG and multiply by 131.25. that will give you your ABV.

check it through http://beercalculus.hopville.com/ and plug your numbers in. that will also give you a good estimate