How accurate is a vinometer?

[REDRUM]

Hi all,
Just wondering how accurate a vinometer usually is? This sort of style:

Tested my Grenache-Shiraz wine at 9% abv - it does taste very light & the Grenache was picked quite early, but even so that seems a very low measurement.

Is this the most accurate way to get an alcohol content reading for a small home winemaker?

 

[Boatboy24]

The most accurate way for the home winemaker, IMHO, is to subtract your ending SG from the starting SG and multiply by 133. I have a vinometer, but have never used it, because I've read they are completely unreliable. I've been meaning for some time to take readings with it and compare to my 'calculated' ABV, but just haven't gotten around to it.

 

[dralarms]

Ain't worth a crap unless the wine is completely dry and you happen to get a good one. I have 2, the first is pretty accurate, the second one says water is 25% alcohol.

 

[grapeman]

How accurate? Not very. I threw mine out years ago.

 

[seth8530]

I would say the accuracy would depend on just how dry the wine is.

 

[JohnT]

Seth, the accuracy depends on the individual unit. By and large, they are not worth a damn.

 

[REDRUM]

Haha!
Sounds pretty emphatic. Next time I'll remember to take an SG reading at the start of the ferment.