Measuring ABV Without OG

[Dirt_McGirt]

Is there a way to measure the ABV of a beer once it's brewed without knowing the OG? I know it's not possible via hydrometer, but wondering if there are other devices/techniques that can do this.
Thanks!

 

[ArizonaGoalie]

Before I measured OG and FG, I just guessed on the ABV based on my extensive beer drinking and fine beer palate.

In all seriousness, I simply guessed with confidence and authority and the people who shared my beer never questioned it.

I felt much better once I started measuring OG. It's simple and worth it.

Oh, there are also magic beer fairies out there who measure ABV, but they are very hard to find. :smack:

 

[meatcleaver]

you can plug your info into a calculator like this. http://www.brewersfriend.com/homebrew/recipe/calculator/

 

[brewfun]

Is there a way to measure the ABV of a beer once it's brewed without knowing the OG? I know it's not possible via hydrometer, but wondering if there are other devices/techniques that can do this.
Thanks!

Math.

If you know your mash efficiency, you can calculate the OG from the grain weight and boil off. Even if you don't know the exact efficiency, you can estimate from a nominal 70%.

 

[Calder]

Measure FG with an Hydrometer and refractometer and you can get a pretty good estimate of OG by plugging the values into a calculator...... then calculate abv.

 

[Gavin C]

Is there a way to measure the ABV of a beer once it's brewed without knowing the OG? I know it's not possible via hydrometer, but wondering if there are other devices/techniques that can do this.
Thanks!

Yes there are but you need access to some fancy do-hickeys

• Mass spectrophotometry/ spectroscopy
• Gas chromatography

 

[bradleyhunt]

Build your recipe in Beersmith and get it close