ALCOHOLOMETRY OF SUGARY LIQUORS Using a Refractometer
Accurate Determination of Alcohol with Semimicro Still and Refractometer
It’s not possible to determine accurately the alcohol content in alcoholic beverages which contain sugar or extract like liqueur, beer, infusions, wine, or mash (e.g., turbo yeast fermented mash) if using simple measurement methods like an alcoholometer (hydrometer), refractometer, or vinometer because in all cases the dissolved sugar and extract distort the measurement. Therefore previously the sample has to be distilled. The distillate is free of distorting substances, so the indicated value of the measurement device like a refractometer is true. But the volume of the sample has changed due to distillation (though not the amount of alcohol when distilling completely), so the value has to be converted accordingly.
Alcohol content of distillate: 12 % ABV
Volume of distillate: 0.41 ml
The alcohol content of the sample is 9.8 % ABV.
ABV: Alcohol By Volume (alc./vol.)