Essentially, muddling is a technique used to release essential oils, juices, or other flavors and aromas from ingredients.
Most bartenders use a small club-like tool called a muddler, which looks like a tiny baseball bat with a flat or rounded end. Similar to using a mortar and pestle, the ingredients are placed inside a cocktail glass or shaker (but no ice yet), then the muddler is used to gently crush the ingredients at the bottom of the glass. After that, the muddler is removed and liquid ingredients and ice are added to finish the drink.
Frequently-muddled ingredients include herbs (mint, basil, cilantro, etc.), fruits (citrus fruits, berries, peaches – usually the goal is to squeeze out the juice as well as the flavors), and vegetables (cucumbers, chile peppers, tomatoes – usually soft and slightly fibrous veggies that will release juices or oils when bruised. Hard vegetables, like carrots, should be pureed or juiced rather than muddled.)
A few tips to help you muddle through:
Use the right tool: Although a plastic or wood muddler is best for the job, you can also use the back of a spoon to crush ingredients.
What’s in your glass? If you’re trying to release oils from delicate leaves like mint or basil, use light pressure. If the goal is to pulverize thicker ingredients like peppers or cucumbers, you can crush away more aggressively. (whew!)
Be abrasive: If a recipe calls for sugar or salt, consider adding it to your muddling glass. The coarse texture will aid in the muddling process.
Add an aromatic touch: Muddling releases aromas, but adding in liquids and ice can dampen the fragrance. Consider adding a complementary garnish to heighten the scent experience, such as a fresh round of cucumber perched on the side of the glass for a cucumber drink, or a couple of whole, beautiful berries speared on a toothpick for a berry-based Margarita. If basil is muddled in the glass, select one fresh, whole basil leaf, briskly slap it between your palms to release the oils (“spanking,” in naughty bartender parlance), then float it on top of the drink and serve right away.