Muddling is an important technique in cocktail making. The idea is to use a muddling stick to extract juice or essential oils from fruit and herbs.
When muddling, lightly push on the ingredients (such as fruit and herbs) in the bottom of a mixing glass with a flat-bottomed muddling stick until the juice is extracted. You don’t want to kill it or you’ll get a lot of bitter taste. Once your ingredients are combined, you typically add ice and the remaining liquid ingredients prior to shaking your cocktail.
A muddling stick or muddler is often shaped like a baseball bat and is commonly made of wood. You will also find muddlers made of metal or plastic with teeth on the bottom. Use the kind with teeth carefully as people tend to over-muddle with these and end up with a bitter drink.