For a drink with only three ingredients — rye whiskey, sweet vermouth, and Angostura bitters — it's easy to screw up a Manhattan, and the simplicity might actually make it more difficult than other drinks. If you're at a bar and want to know if you'll be served a great Manhattan or a subpar one, there's one thing you need to pay attention to.

Good-quality sweet vermouth is the make-or-break ingredient for a Manhattan, and if the vermouth is old or not properly stored, it will give the drink a sour taste. Vermouth must be stored in the refrigerator after opening, so if you see a bottle of vermouth sitting on a shelf at a bar, you probably don't want it in your Manhattan.

You can also scan a bar's cocktail menu before ordering a Manhattan, and if few to none of the drinks use vermouth, the bottle has probably been sitting out for a long time, slowly degrading. If the bar doesn't have a cocktail list or if it's clear that the focus is more on beer, liquor, and well-drinks, you might want to opt for something else.