# ABV measurement sans hydrometer/refractometer

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#### thomasrj

##### Active Member
I hope this is the right spot; I figured the science-minded folks would know how to answer this best. Thanks in advance for your help.

The question:

Is there a (relatively) easy way to determine alcohol content, either %mass or %vol, without using hydrometer or refractometer readings? Related: Can a hydrometer get out of whack and just give erroneous readings?

Here's why:

I recently brewed a milk stout and I don't trust the ABV calculation based on the hydrometer readings. OG was 1.100 and FG was 1.024. By my calculation, this should indicate a touch over 10% by volume. I've had a lot of ten percent beers, and this is not one.

I'm looking for a way to verify this. I'm a grad student so I have access to standard lab equipment/supplies if necessary.

I did a hydrometer calibration check with cool tap water and had a reading of 1.001, which I think is reasonably accurate for a municipal supply of treated surface water.

#### Haputanlas

##### Well-Known Member
Can you post the recipe and your volume of wort after the boil?

I have doubts about the 1.10 OG if you weren't anticipating a huge beer.

#### ajdelange

##### Well-Known Member
The usual method of determining ABV is to separate the alcohol from the beer by distillation and then measure the density of the distillate whose volume has been adjusted to that of the original beer sample. Gas chromatography is sometimes used and there are special (read expensive) instruments that look at density and NIR absorption of the beer and determine ABV from that.

Accurate determination of the density of the distillate requires that a digital density meter be used (expensive) or that one go through the elaborate steps required in making the measurement with a pycnometer. So I guess the answer is no, there is no simple method.

OP
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#### thomasrj

##### Active Member
So I guess the answer is no, there is no simple method.
Well, that figures...

It was 6.6 lb of LME and 0.5 lb each of maltodextrin and lactose. I was expecting around 1.064, but I figured the hydrometer couldn't lie. Maybe I just pulled the sample from a thick part of the wort or something like that.

Thanks for the help, guys. I guess in the long run, it doesn't really matter--it tastes good either way

#### nofootbreak

##### Well-Known Member
Your reading is either due to temp of the sample, stratification of the wort, bad hydrometer or volume. Extract is extract. No way to magically get 34 gravity points

#### Haputanlas

##### Well-Known Member
Well, that figures...

It was 6.6 lb of LME and 0.5 lb each of maltodextrin and lactose. I was expecting around 1.064, but I figured the hydrometer couldn't lie. Maybe I just pulled the sample from a thick part of the wort or something like that.

Thanks for the help, guys. I guess in the long run, it doesn't really matter--it tastes good either way
I'm assuming this is a 5 gallon batch?

#### Haputanlas

##### Well-Known Member
Well, that figures...

It was 6.6 lb of LME and 0.5 lb each of maltodextrin and lactose. I was expecting around 1.064, but I figured the hydrometer couldn't lie. Maybe I just pulled the sample from a thick part of the wort or something like that.

Thanks for the help, guys. I guess in the long run, it doesn't really matter--it tastes good either way
At 5 gallons, I calculate that your OG should have been 1.052. With extract it's pretty hard not to hit your numbers.