At one time Moscatel de Setubal was shipped in cask on long sea voyages, much as was Madeira. However this was discontinued long ago for both Madeira and Setubal. However the Fonsecas kept casks of this very old wine and would sometimes bring it out for special visitors. They made a little of it available several years ago. I obtained my 3 bottles at auction, and this is the first time I have tasted it.
The wine is very dark mahogany, but clear. The first thing you notice is the extremely intese bouquet when you pull the cork. There is intense caramel, dark raisins, and an extremely intense perfume. You are expecting to taste liquid fruit cake from the nose. However the taste is much like cherry liqueur rather than the expected black raisins. There is very intense sweetness and caramel and butterscotch in the taste also. The aftertaste is extremely long. I would never have guessed that this is a Moscatel de Setubal based on tastings of their current younger wines.
Serena Sutcliffe was fortunate to taste a vertical of Setubals from cask served at Fonsecas establishment sometime around about 1980. Wines were tasted at 10 year intervals starting with the 1978 and going back to the early 1900s. Then the Torna Viagem was brought out, and here is how Sutcliffe described it. "Senhor Soares Franco finally produced a wine hors d'age, the 'T.V' (Torna-Viagem) shipped to and from the tropics in the manner of Madeira. Pitch black and 'chewy', with a nose that was not so much maderized as perfumed, it tasted of an unctuous cherry liqueur." You would need to read her complete notes on these wines for a full general description. She published this in her 1981 rewrite of Andre Simon's Wines of the World.
Of course what Sutcliffe tasted and what was later sold may come from different casks. In general my impressions agreed with Sutcliffe's. My wine may not have been quite as dark in color. However it had thrown some crust on the sides of the bottle, so that may have reduced the color a small amount.
It comes as absolutely no surprise that Muscat wines can age well for a very long time. Madeiras made from the Muscat grape in the 1800s still often are in good form. And then there is classic Constantia. Constantia from the late 1700s and early 1800s still can be quite drinkable, but it is next to impossible to find anymore, even at auctions.