Typecocktail shakers & mixers
Apparatus used in a style of drink mixing whereby fruit peels, herbs, cube or granular sugar, and other "solid" ingredients are placed in the glass, often with a small amount of sugar, liqueurs and bitters, and then crushed, abraided and/or bruised with a grinding motion of the pestle-like muddler, a shaped stick of hardwood. Additional liquid ingredients are added after muddling is complete.
Note: a common mistake is not muddling long or thoroughly enough. This can result in an inferior drink insofar as the general intention is to extract and activate as much flavor as possible out of ingredients that don't give up everything so readily. For example, muddling ingredients for an Old Fashioned Cocktail is all about extracting the maximum essential fruit oils from the orange peel, melding it with the sugar, water, and bitters before the addition of the rye or Bourbon whiskey. If the fruit isn't muddled seriously, much of the underlying flavor ends up missing.
Muddlers come in many shapes and sizes and the best are made of unstained, unvarnished hardwood. Muddling can serve various purposes. Besides the use outlined above, in some regions of the United States all ingredients including ice are combined in a mixing glass and the muddler is used with a strong and rapid up-and-down pumping movement to crush and agitate the contents of the glass. the results are then either poured into a tall glass (or goblet) or strained into a stemmed cocktail glass.