Named after the Portuguese-owned island where it's made, Madeira is a distinctive fortified wine that's subjected to a lengthy heating process during maturation. It can range in color from pale blond to deep tawny and runs the gamut from quite dry to very sweet. The pale golden Sercial is the lightest, driest Madeira, while the rich, dark Malmsey is the sweetest. Bual and Verdelho are both medium-sweet wines. The flavor of American-made Madeiras cannot compare with that of the Portuguese originals . . . but then they're a fraction of the price. The lighter Madeiras are often served as apéritifs, while the richer, darker Malmsey is perfect for after-dinner sipping. Madeira is also an excellent cooking wine and can be used in both sweet and savory preparations.