Dry Vermouth (Old & New)

Looking back on it, I'm not sure why I thought I could get away with keeping an opened bottle of dry vermouth in the cabinet for more than a year. I know that wine, once opened, starts to oxidize and can turn a little sour after just a few days. For some reason, though, I'd always assumed my trusty bottle of 21% vol Noilly Prat - essentially a fortified wine - would go on and on, tasting just right. I'd managed to make it last so long because I only ever use the stuff to make martinis - and even then I only use a small dose to balance the gin. The problem, partly related to the above, is I'd forgotten what fresh dry vermouth was supposed to taste like. In any case, I kept using it, until the bottle was nearly empty and I was ready to buy a new one. Then I read about an interesting taste test on top cocktail blog Oh Gosh! and decided to, well, copy the idea. Here follow my blind tasting notes for two bottles of Noilly Prat, the only difference being that one was 'aged' in the bottle for an extra year.

Old one (pictured on the left)

Colour: Dark gold or amber.
Aroma: Old, pungent, astringent, sweet apples. Off.
Taste: Bitter, strong, sour, in your face.

New one (on the right)
Colour: Light straw.
Aroma: Aromatic, of pear.
Taste: Complex, rich, strong, sweet, white wine, long finish.

The difference in taste was startling. The only way to make the old one tolerable, I realised, would be to smother it in gin - exactly what I'd been doing for the past few months. The new one tasted far more complex, giving me a long-forgotten sense of the 20 herbs and spices that go into making this concoction. It was a different drink altogether, and one I plan in future to enjoy - from the fridge - for no longer than 12 weeks at a time.