Follow the below tips to get perfectly pickled red onions, every time.\n\n1. Experiment with [different kinds of vinegar](https://www.masterclass.com/articles/a-guide-to-all-the-cooking-vinegars-you-need-to-know), such as apple cider vinegar, distilled white vinegar, or red wine vinegar.\n2. Prep the raw onions ahead of time, using your sharpest knife to slice onions into thin rings or half-moons.\n3. Try adding whole spices, such as black peppercorns, [allspice](https://www.masterclass.com/articles/what-is-allspice-how-to-cook-with-allspice-and-homemade-allspice-substitute-recipe), or bay leaves alongside kosher salt in your pickling brine. For a spicy flavor, add garlic cloves, thinly sliced jalapeños, or red pepper flakes to the vinegar mixture. \n4. Pickled red onions can be refrigerated for months, but they’ll have the best flavor if used within about a week.\n5. Refrigerate pickled onions in a jar or other glass container. (Metal can react with the vinegar, and plastic may absorb flavors.)\nOnce you know how to make pickled red onions, use them to add acidity and mild onion flavor to:\n\n1. __Chef Thomas Keller’s recipe for arugula salad with pickled red onions__. The bright acidity of the pickled onions is a perfect complement to this lightly dressed leafy salad. Lightly dress arugula with olive oil, using just enough that the leaves take on a light sheen, and toss. Sprinkle with salt. The oil will help the salt cling to the arugula. Garnish with almonds and pickled red onions and toss with balsamic vinegar.\n2. __Mexican cuisine__. Top tacos ([pulled pork](https://www.masterclass.com/articles/how-to-smoke-pork-butt-pork-shoulder-with-barbeque-pitmaster-aaron-franklin) or vegan cauliflower are great options) with a tangle of bright pickled onions.\n3. __Main dish meats__. Serve pickled onions as an acidic condiment alongside barbecued pork shoulder or braised beef.\n4. __Sandwiches__. Chop pickled onions and add them to a grilled cheese sandwich.\n\nFirst-time picklers: fear not. [Michelin-starred Chef Thomas Keller](https://www.masterclass.com/classes/thomas-keller-teaches-cooking-techniques) of The French Laundry shares an easy recipe for quick pickled red onions.