Often called "The dog choker" for acidity so high that it would choke a dog, the Sercial is a Portuguese varietal that has long been a part of the production of the fortified wine Madeira. Grown on both the mainland (as Cerceal and Esgana Cão) and on the island of Madeira, the name Sercial is used more to denote the lighest and driest style of Madeira, of which most comes from the Sercial varietal. Madeiras in general can often take decades to reach maturity and the Sercial can require an even longer period of time. Those lucky enough to find Madeiras dating back to the turn of the 20th century (or even further back) will be treated to an intense and sublime concoction that combines the best attributes of Sherry and Tawny Port along with a vein of acidity and an impossibly long finish. Already oxidized, Madeira can be opened and recorked without fear of damaging the wine. The best examples will continue to improve seemingly forever.