Whenever a dish needs a pop of brightness, acidity, or color, I turn to the trusty jar of pickled red onions in my fridge. Made by soaking red onions in a simple vinegar solution, this simple condiment brings acid and crunch to braises, slow-cooked soups and stews, and dark green salads. The gorgeous, magenta-hued strands can turn any one-tone dish (looking at you, pork tenderloin) into a vibrant meal.
I make a batch of pickled red onions every week, filling a clean mason jar with fresh sliced onions, pickling liquid, and herbs or spices. Follow this basic pickled red onion recipe to make your own, then get creative with flavors and seasonings. But first, let’s start with a little science:
Great question. According to culinary scientist Jessica Gavin, the anthocyanins (or coloring pigment) in the red onions react with the acid in the hot pickling liquid to turn the onions a radiant pink. The low pH of the pickling liquid also helps preserve the onions’ crunch, she notes. If you don’t want the vibrant color, you’re better off pickling white onions. But who wouldn’t want a pop of color on their plate? Eat the rainbow, as they say.
How to make pickled red onions:
To make pickled onions, you’ll steep sliced red onions in a vinegar solution (in its most rudimentary form, a 1:1 mixture of water and vinegar, plus sugar and salt). Stash them in the fridge and a day later, you’ll have a jar of fresh pickled onions, ready to add to countless dishes.
This easy recipe for pickled red onions requires just four ingredients and about 12 hours (psst: we’ve also got a shortcut version below, ready in as little as 15 minutes). Once you’ve mastered the basic pickling formula, there are endless ways to experiment—we’ll get into a few variations below. But first, let’s break down the components that go into perfect pickled onions.
Red onions: Red onions have a sharper flavor than white and yellow onions, which makes them ideal for pickling. Slice the onion into rounds, half-moons, or from pole to pole with a sharp chef’s knife or, for the most uniform cuts, a mandoline.
Vinegar: You can make pickled red onions with pretty much any type of vinegar. Distilled white vinegar offers a blank canvas, so the flavorings you add can really shine. But you can use apple cider vinegar, white wine vinegar, champagne vinegar, rice vinegar, or any type you have in the cabinet. I like to enhance the onions’ natural pink color with red wine vinegar.
Water: Cutting the pickle brine with water keeps the vinegar’s puckery punch in check. Recipes generally recommend a 50:50 ratio; for a pickle with more bite, you can use 3 parts vinegar to 1 part water. For one that’s more mellow, skew in the opposite direction. Filtered tap water is fine here—the important thing is to ensure it comes to a boil, as the hot water–vinegar solution will help the sugar and salt dissolve.
Sugar: A hint of sweetness balances the acidity of the pickling solution. You can use any type of sweetener here—white sugar has the most neutral flavor, but brown sugar, maple syrup, honey, or agave syrup will all work.
Salt: The type of salt you use matters here. Almost all pickling recipes work best with kosher salt, which dissolves most readily into the vinegar solution and prevents it from going cloudy. The saltiness by volume also changes based on the size of the salt crystals, so avoid sea salt, flaky salt, or any coarse-grained salt, which may make the solution too salty.
Our go-to pickled red onion recipe:
- 1 medium red onion, thinly sliced
- ½ cup distilled white vinegar, or the vinegar of your choice
- ½ cup filtered tap water
- 2 tsp. granulated sugar
- 1½ tsp. Diamond Crystal or ¾ tsp. Morton kosher salt
- Place 1 medium red onion, thinly sliced, in a glass container or mason jar. Set aside.
- Bring ½ cup distilled white vinegar, ½ cup water, 2 tsp. sugar, and 1½ tsp. Diamond Crystal or ¾ tsp. Morton kosher salt to a boil in a medium saucepan over medium-high heat, stirring until sugar and salt dissolve completely.
- Pour brine over red onions in mason jar and let cool at room temperature. Cover and chill at least 12 hours and up to 4 days.
Once you’ve got the basic formula down, feel free to add spices, herbs, or other seasonings to your pickling liquid. Whole spices shine here: I like to add 1 tsp. coriander seeds, 1 tsp. cumin seeds, and/or ½ tsp. whole black peppercorns. To draw out the flavor of the spices, toast them in a dry skillet until fragrant (1–2 minutes) before adding to your pickle jar.
You can also stuff fresh herbs into the jar—dill is a popular choice (think dill pickles), but sprigs of fresh oregano or thyme work well too. Boost the flavor of the brine with a smashed garlic clove, a few strips of citrus peel, or a bay leaf. Want a kick of spice? Add red pepper flakes or a halved jalapeño to the jar. You can even add in other veg, like thinly sliced radishes, to make an assortment of pickles.
How to make quick-pickled red onions:
To make proper pickled onions, you’ll need at least 12 hours for the vinegar solution to fully permeate the onions. But if dinner’s already in the oven and it would taste that much better with pickled red onions to garnish, the quick pickle is the one for you. With the below techniques, you can make quick-pickled onions in as little as 15 minutes.
Your first option is simple: Follow the instructions outlined in the recipe above, but heat the brine just until it simmers around the edges. Then pour the warm vinegar mixture over the sliced onions; they should be ready in about 15 minutes.
Don’t want to mess with a boiling-hot pickling solution? You can also macerate very thinly sliced onion rings in lime juice, stirring occasionally, until they soften and turn bright pink in color. It takes about an hour—find more detailed instructions in chef Steven Satterfield’s recipe for The New Wedge Salad.
Epi contributor Grace Elkus has all the intel on proper pickle storage, but here’s the short of it: Unless they undergo a water-bath canning process, which involves sanitizing, sealing, and processing the jars in boiling water, pickles—whether made with cucumber, red onion, or any other veg—need to be kept cold. Store pickled red onions the same way you’d store an open jar of dill pickles: in the fridge.
If you’re making a fresh batch of pickled red onions, let them cool completely at room temperature before stashing them in the fridge. Pickled red onions typically last for up to a week. You can tell it’s time to toss them if the color darkens significantly, the brine becomes cloudy or fizzy, or the pickles go soft.
Our best recipes with pickled red onions include plenty of salads, but also stews and sandwiches. You can use pickled red onions in any dish that could use a pop of acid: Add the crunchy condiment to a charcuterie board for a snacky supper. Throw them on a grilled cheese sandwich, pulled pork sliders, or a tray of nachos. Lay them atop avocado toast, tuck them into tacos or burritos, or toss them in vinegar-dressed potato salad.