TORONTO, ON - JANUARY 28: Vermouth is in the middle of a major cycle of discovery.  Vermouth is used in a variety of cocktails and have signs all over Europe. Bottles of vermouth are seen in the Black Hoof Cocktail lounge on Dundas street west of Bathurst.  I don't think the owner wants the name used.
13-01-28  Richard Lautens/Toronto Star        (Richard Lautens/Toronto Star via Getty Images)
Food - Drink
The Reason You Should Finish Up That Bottle Of Sweet Vermouth
By SYLVIA TOMCZAK
While it's typically served as an apéritif, vermouth has become a key ingredient to add depth to classic cocktails like the Negroni or Martini. However, fans of this bittersweet booze should know that rather than leaving it in the liquor cabinet, it’s best to finish up your bottle of vermouth sooner rather than later.
Sweet vermouth begins to oxidize the second you open the bottle, and its characteristic herbal aroma and vibrant taste can fade faster than you think. Unlike distilled booze, vermouth should be kept in the fridge after opening to preserve its integrity and quality, and an opened bottle keeps well for about two months.
If your vermouth has been kept in the fridge for over two months, it won't be tasty to drink on its own anymore, but you don't have to throw it away; instead, try cooking with it. Add a splash of vermouth to pan sauces, reduce it for glazes, or you can even evaporate it if you have the right tools.