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
Phenolic content in wine tannins they increase the stability of a wines color-meaning that a wine will be able to maintain its coloring for a longer period of time. The amount of catechins present varies among grape varieties with varietals like Pinot noir having high concentrations while Merlot and especially Syrah have very low levels. As an antioxidant, there are some studies into the health benefits of moderate consumption of wines high in catechins. In red grapes, the main flavonol is on average quercetin, followed by myricetin, kaempferol, laricitrin, isorhamnetin, and syringetin. In white grapes, the main flavonol is quercetin, followed by kaempferol and