Madeira wine is a fortified wine produced on the Portuguese island of Madeira. It is known for its unique aging process, which involves heating the wine and exposing it to oxygen, resulting in a rich, complex flavor profile. The wine can be made from various grape varieties, including Sercial, Verdelho, Bual, and Malmsey, each offering different sweetness levels. Madeira wine is often enjoyed as an aperitif or dessert wine and is celebrated for its remarkable longevity. It can last for decades, even centuries, without losing its quality, making it a popular choice for collectors and enthusiasts alike.