The EasyDens is a digital density meter which can determine the sugar content (g/L) in binary mixtures, like sugar-water mixtures. As the density of water is known, the EasyDens can calculate the concentrations based on the difference between the measured density and the density of pure water.
However, if the sample contains several components such as sugar, alcohol, water, acids, etc. (like in fermenting or finished wine) the density measurement can no longer be used to directly determine the sugar content because sugar and alcohol have different effects on density.
With the Wine Meister mobile app you can calculate the residual sugar (Learn more...)
Spectroscopic measurement techniques, like the Lyza 5000 Wine from Anton Paar can be used to determine the amount of residual sugar and 13 other parameters in finished wine, must and must in fermentation.