Oechsle scale The mass difference between equivalent volumes of must and water is almost entirely due to the dissolved sugar in the must. Since the alcohol in wine is produced by fermentation of the sugar, the Oechsle scale is used to predict the maximal possible alcohol content of the finished wine. This measure is commonly used to select when to harvest grapes. In the vineyard, the must density is usually measured by using a refractometer by crushing a few grapes between the fingers and letting the must drip onto the glass prism of the refractometer. In countries using the Oechsle scale, the
History of the wine press from olives. This press would entail laying the grapes out underneath several planks of wood and then weighing the planks down with rocks to press the juice out from the grapes. The wine made from these rudimentary pressing wasn't held in high esteem by the Greeks, often tainted with impurities and having a short shelf life. Much more prized was the wine produced from "free run" juice that was released by the grapes under their own weight before any treading or pressing. This wine was believed to be the most pure and was often used for medicinal purposes. In the