A little while ago, I discussed the Manhattan cocktail. Rather than updating the original post, I decided to discuss some news on that front here.
Some further elaboration from the same article:
The Manhattan is subject to considerable variation and innovation, and is often a way for the best bartenders to show off their creativity. Some shake the ingredients with ice in a cocktail shaker instead of stirring it, creating a froth on the surface of the drink. Angostura are the classic bitters, but orange bitters, Peychaud’s Bitters, and even the lack of any bitters, may be used; using Fernet-Branca yields what is called a Fanciulli cocktail. Some make their own bitters and syrups, substitute comparable digestifs in place of vermouth, specialize in local or rare whiskeys, or use other exotic ingredients. A lemon peel may be used as garnish. Some add juice from the cherry jar or Maraschino liqueur to the cocktail for additional sweetness and color.
Originally, bitters were considered an integral part of any cocktail, as the ingredient that differentiated a cocktail from a sling. Over time, those definitions of cocktail and sling have become archaic, as sling has fallen out of general use (other than in certain drink names), and cocktail can mean any drink that resembles a martini, or simply any mixed drink.