Madeira is a group of islands off the coast of Africa, and have long been known for wine production. Back in the colonial days, it became a favorite of our founding fathers. During shipment, however, the wine was exposed to excessive heat and movement - the things that usually will destroy wine. But it instead gave the wine a unique flavor much favored by the colonists, and created a wine basically unaffected by further temperature extremes. Since then, the heating process, which lasts at least 3 months, has been an integral part of the making of Madeira wines. It also results in the wine being extremely long lived, even after opening.