Actually the name of a few different varietals grown on the island of Madeira off the coast of Portugal, one of which is the Sémillon of Bordeaux. Also spelled Boal, the Bual refers almost more to a style of the delicious fortified wines of Madeira. Of the four styles of Madeira, Bual is on the sweeter end of the spectrum. The high acidity in the Bual grape combined with Maderization, a process in which the wine is fortified and then slowly cooked in barrel over a period of many years, allows the wine to acheive incredible longevity. Bual Madeiras from the 1800s are still in good condition and some examples from the 17th century though rare are not unheard of. At one point Madeira was as popular as Port, though sales have dropped significantly in the last 50 years. Older Buals have an incredible combination of sweetness, body, texture and acidity, all of this rounded out with a complex array of flavors that can range from caramel to green apples and from smoke to molasses. They are rare and expensive, but highly recommended.