The alcohol content of a beer, wine and cider may easily be established by combining the results of two simple test measurements, that of a refractometer (RI-Zeiss) and a hydrometer (SG).
Calculation of results is by way of either a paper lookup table supplied with the refractometer or by a simple Internet calculator that can be accessed via a networked PC or web enabled mobile phone.
a few drops of sample are needed to make the refractometer reading,
while the S.G. is measured in the usual way with the hydrometer jar. The
process takes only a few minutes to carry out and an accuracy of about ±0.5%
alcohol can be obtained using reasonable care in ensuring that both readings
are made at the same temperature.
If the instrument is used with care and
cleaned as recommended after use, it
should give many years of accurate and trouble-free service.
|Light dry table wine
S.G. = 0.993 & Refractometer reading = 37
D (S.G. value) = (0.993 – 1) x 1000 = -7
R-D = 37 – (-7) = 44
Alcohol content = 10.7%v/v
|Sweet dessert wine or Sweet
S.G. = 1.015 & Refractometer reading = 72.5
D (S.G. value) = (1.015 – 1) x 1000 = +15
R-D = 72.5 – (+15) = 57.5
Alcohol content = 15.7%v/v
|38-49||OPTi Duo Brew digital refractometer (ABV/Wort)|
|45-22||Eclipse Wine (%ABV) refractometer|
|44-839||Hydrometer 0.98 to 1.0 50 S.G.|
Note: Due to the achievable accuracy of this measurement system, results may not be suitable for duty declaration.
To purchase portable test equipment for brewers, cider and winemakers, please contact: