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
Quinta classification of Port vineyards in the Douro Quinta classification of Port vineyards in the Douro The Quinta classification of Port vineyards in the Douro is a system that grades the "terroir" and quality potential of vineyards in the Douro wine region to produce grapes suitable for the production of Port wine. In Portuguese, a "quinta" is a wine producing estate, which can be a winery or a vineyard. While other wine classification systems may classify the winery (such as the 1855 Bordeaux classification), the Douro quinta classification is based upon the physical characteristics of the vineyard. The classification system is run by the "Instituto dos Vinhos do