Viva La Vya!
By F. Sot Fitzgerald
Few Americans know what vermouth is or what it tastes like.  It's just something that never caught on here.  Those folks I know who have tasted vermouth have never had it straight.  They've had a dribble of dry vermouth in their Martini (gin) or Martivi (the vodka version), or a little sweet vermouth in their Manhattan (bourbon). But that's it. 

I myself first tasted dry vermouth straight in my twenties.  I had gotten the idea from Ernest Hemingway's A Farewell to Arms, wherein Frederic Henry, the leading man, regularly drank vermouth while reading the newspapers.  Whether it was dry or sweet vermouth that he guzzled- I cannot recall.  Regardless, I had only a rotten bottle of dry vermouth at that time and so took to knocking back iced glasses of it as I read novels and studied for my university exams.
So what is vermouth?  Vermouth is wine that has been fortified with more alcohol (thus vermouths are usually 14-20% alcohol, more than wines) and assorted herbs, spices and botanicals (read- "leaves, roots, stems of plants").  To over simplify a bit- sweet vermouths are made with red wines, dry vermouths almost if not entirely with white wines.

Now, excepting those who drink Rob Roys (scotch, sweet vermouth & lemon peel), Manhattans (rye & sweet vermouth), and the like, sweet vermouth is likely to be a total mystery to most folks. 
 
I know that in my first decade of bar hopping I never sauntered up to the bar and said, "Give me a sweet vermouth on the rocks."  Speaking of which- typically, the sweet vermouths found behind most American bars are slop- cheap red wine with wine lightning added.  Their sole merit is that adding them to your whiskey will rub away its rough edges.  And as for drinking them straight- well, that's only for those who think Richard's Wild Irish Rose