A cocktail onion is a pickled garnish for cocktails such as martinis. Along with olives and maraschino cherries, they make up a trio of three classic edible garnishes which can be found in well stocked bars. Like these other garnishes, cocktail onions usually come in large containers which hold the onions along with their pickling medium, usually brine. Many grocers and liquor suppliers stock cocktail onions.
Typically, a pearl onion is used as a cocktail onion. Pearl onions are naturally sweet, which makes them an excellent pairing with many cocktails. Other sweet onions such as the crystal wax, also known as the white Bermuda, are also sometimes used. In many cases, white varieties of these sweet onions are used, since many consumers expect cocktail onions to be white. However, yellow or red sweet onions may be used as well.
Most typically, cocktail onions are brined, and they are sometimes seasoned with turmeric, paprika, or similar spices. In many cases, sugar is added to the brine to bring out the natural sweetness of the onions. The sweet, slightly salty brined onions pair well with tart drinks. Salty, savory, or straight drinks are also enhanced with the addition of a cocktail onion, which can be eaten after the drink is consumed or left behind, depending on personal taste.
Generally, the onion retains a slightly crunchy texture through the brining process, which can add a different mouthfeel to the drinking experience. Since the cocktail onion is made from a sweet onion, it is unlikely to upset the digestion with a sulfurous or eye watering taste, although some cultures use more pungent onions as cocktail garnishes.
To make cocktail onions at home, start with one pound of pearl or other sweet onions. Blanch them briefly to loosen the skins, and trim off the roots and stems, taking the skin off along with them. Next, measure out one half cup each of white or sherry vinegar, cider vinegar, water, and salt. Add one quarter cup sugar and spices to taste such as mustard seed, turmeric powder, juniper berries, peppercorns, allspice, rosemary, or chile peppers. Heat this mixture until it boils, stir in the onions, cook for another two minutes, and then remove from the heat. Once it has cooled, add one cup of vermouth, and store in an airtight jar in the fridge. When a cocktail onion is required, use a clean utensil to fish it out.
wiseGEEK would like to remind readers to enjoy their cocktails responsibly, cocktail onions or not!