What Exactly Are Cocktail Onions (And Can You Cook With Them)?

Order martinis off certain bar menus and you'll find that your glass comes garnished not with an olive or a lemon twist, as you might expect with a classic dirty martini or a classic gin martini with a twist, but, instead, with a small, tiny onion. These are cocktail onions. But what is that cocktail onion? Is it just, literally, a tiny onion that your bartender dropped in your glass, right before serving?

Not quite. While a cocktail onion is a real, albeit small, onion, just like a Vidalia or the onion on your burger, the onion must be prepared a certain way to be considered a traditional cocktail onion. To make cocktail onions, pearl onions are (just slightly) cooked and pickled in a brine, sometimes using extra spices and sometimes not. As the onions sit in the brine, over time, they take on the brine's flavor, so that when they're added to your drink, they impart an extra layer of sweet-salty-savory goodness. Depending on the maker, the brine ingredients will vary, but popular choices include a variety of different kinds of vinegar, sugar, and chili flakes.

Yes, you can cook with cocktail onions

Given that cocktail onions are simply pearl onions pickled in a brine, you could probably guess that there are uses for this often-overlooked ingredient beyond your martini glass. In fact, you can use cocktail onions just about anywhere you might normally use pearl onions, just expect some extra briny flavor.

One journalist at the Staten Island Advance wrote that they took a leftover jar of cocktail onions, drained the onions, and cooked them in butter, before adding extra veggies, to create a flavorful topping for grain, bean, and pasta dishes. On Reddit, one user asked for ideas on how to use a leftover jar of cocktail onions and was met with suggestions including adding them to kebabs, stews, salads, roasts, and meatballs. Other suggestions included finely chopping the onions and adding them to sandwiches, or combining them with mayonnaise for an in-a-pinch version of tartar sauce. So, yes, there are plenty of ways to use cocktail onions beyond your bar cart, so long as you enjoy the unique flavor.