Osborne Sherry 10 RF Oloroso Medium is an old, mature, powerful, off-dry Oloroso Sherry
The quality designation "Oloroso" refers to a sherry with a walnut character and a strong, full-bodied aroma. The name "Oloroso" means "fragrant"; the abbreviation "RF" stands for "Reserva Familiar", because originally the Osborne family produced Sherry Oloroso only for their own needs. Only 10 barrels of this sherry were produced – hence the name Osborne Sherry 10 RF.
After pressing and fermentation in modern stainless steel tanks and the addition of wine alcohol up to an alcohol content of approx. 15% vol, the traditional aging of the wines begins in approx. 600-liter wooden barrels, the "butts". These are only two-thirds full, and a protective yeast layer, called "flor", quickly forms on the wine, which protects the young wine from oxidation and is crucial for the formation of the sherry-typical aromas.
During storage according to the so-called "solera system", the barrels are continuously topped up with wine from younger vintages after about a third has been removed from beneath the protective yeast layer. In this way, the best wines pass through many rows of barrels over several years. At the same time, a consistently uniform end product is created through the constant blending of old and younger wine.
A portion of the young wines is prevented from further fermentation early on by the addition of wine alcohol. This results in sweet wines for the production of off-dry and sweet sherry variants through blending. Another part is allowed to ferment completely and is stored after the addition of wine alcohol at about 18% vol, so that no "flor" of yeast can form. These wines oxidize during barrel storage into dark-gold-colored dry "Amontillados" or "Olorosos" and thus contribute to the great variety of sherry styles through mixing with one another.
