The most famous fortified wine of all, Porto, is as Portuguese as a Lodi Zinfandel is Californian. So how must the Portuguese feel now that wineries around the world have seized the word – which, of course, is the name of a city in northern Portugal – dwarfed the "P", amputated the "O" and slapped the four remaining letters onto millions of bottles of a very sticky, ruby-red fortified dessert wine.