Dry Extract in Sherry and Its Evolution in the Aging Process

Abstract

The variation of the dry extract of sherry has been studied during its aging process. These variations have been evaluated, and it has been found that the dry extract of the wines depends fundamentally on the type of aging process to which they have been subjected. In the case of biological aging (Fino-type sherries), there is a decrease of dry extract of the wine in the aging process. This is due to the metabolism of the flor yeast of certain components of the wine, principally glycerol, and to the precipitation of potassium bitartrate during the long stocking period. For these reasons, the dry extract of wines which have been aged biologically can have values below 15 g/L. On the other hand, the dry extract in sherries which have been subjected to a physical-chemical aging process (Oloroso-type sherries) increases. This is due to the concentration of all the components of the wine produced by the evaporation in the aging. For this reason, the values of the dry extract of wines aged by this system can be over 22 g/L.