Thanks to Christian Ferdinand Oechsle, today we can determine the must weight (ratio of sugar to water in grape juice; 1 degree Oechsle corresponds to a sugar content of around 2.6 g/l) and thus predict the alcohol content in wine. He lived at the end of the 18th century and in the 19th century as a mechanic, goldsmith and inventor in southwest Germany. The must scale, also known as a refractometer, is one of his most important inventions. Although, to put it quite correctly, the must scale had already existed for some time, Christian Ferdinand Oechsle’s introduction of the practical graduation on the spindles and his measuring device ensured that the must scale could be made available to winegrowers in series production.
The Oechsle degree itself, expressed in °Oechsle or °Oe, indicates the respective sugar content in the grape must. The alcohol content in the future wine can also be calculated in this way. The must scale works according to the principle that sugar is heavier than water and therefore has a higher density than water. The must scale consists of a glass spindle with a graduated scale that measures the specific gravity of the must. This works according to the following principle: the less the spindle sinks, the more sugary the must is. The scale then shows how high the Oechsle degree is.
For example, 80 degrees Oechsle means that a must with this Oechsle content, fully fermented, produces a wine with 84 grams of pure alcohol per liter, which in turn corresponds to a light wine with an alcohol content of 10.6% by volume. The wines with residual sweetness from the best Swiss winemaker of the decade, Diego Mathier, even have up to 180° Oechsle!
While in France and Spain the unit of measurement is degrees Baumé, in English-speaking countries Brix and in Austria and Italy KMV for Klosterneuburger Mostwaage, the unit of measurement degrees Oechsle is used in Germany, Switzerland, Liechtenstein and Luxembourg.
