Sercial is grown in the highest vineyards on the island of Madeira. It is tricky to ripen at these altitudes and therefore makes a tart, acidic wine. However, extended cask ageing softens and transforms it. Sercial has, of course, given its name to the driest, and perhaps most delicate, of the four madeira styles. Fun fact: Sercial is known as Esgana Cão (Dog Strangler) grown on the Portuguese mainland!