Oechslegrad is the basis for calculating the sugar content in wines, which provides information about the later alcohol content of the wine. The evaluation system is based on the research of the pharmacist Christian Ferdinant Oechsle (1774 - 1852), who for the first time produced an instrument with the Oechslewaage, with which the sugar content of grapes and thus their maturity could be read.
The invention of Oechsle is based on the physical principle that sugar is heavier than water. Thus, the difference between the weight of the liquid contained in the grapes and the weight of water in the same amount provides information about the sugar content of the wine, which is later fermented into alcohol. Today, the alcohol content is determined with the help of a modern refractometer, which records the sugar content based on the refraction of light.
Using a table, the determined value of the grape in degrees Oechsle can be converted into the expected late alcohol content. If a grape reaches 70 degrees Oechsle, an alcohol content of 9.1% vol. Can be expected later in the wine. 80 degrees Oechsle, on the other hand, correspond to an alcohol content of 10.6% vol. As a rule of thumb, the Oechsle degree is more important in northern regions than in southern countries, since the grapes ripen well under good growing conditions.
This test does not require any aids. On the basis of the organoleptic test, the quality of a wine - for example by a tasting person - is assessed exclusively on the basis of the natural senses.