Pickled Red Onion
Tangy, crunchy refrigerator pickled onions made with a simple vinegar brine—ready in 10 minutes and perfect for tacos, sandwiches, and salads.
- 1 cup red onion, very thinly sliced
- 1/2 cup white vinegar or white wine vinegar (see note)
- 1/2 cup water
- 3/4 teaspoon salt
- 2 tablespoons cane sugar (or substitute honey, agave, or another sweetener)
- 1 tablespoon whole spices, any combination (black peppercorns, fennel seed, cumin seed, coriander seed, mustard seed)
- 1 to 2 garlic cloves, sliced
- 1 to 2 bay leaves
- To taste fresh or dried herbs (oregano, cilantro, scallions, curry leaves, dill)
- To taste jalapeño slices
- Using a sharp knife or a mandoline, slice the red onion as thinly as you can manage — you'll need about 1 cup once sliced. Very thin slices matter here more than they might seem, since they let the brine penetrate quickly and give you that crisp-tender pickle texture rather than raw, crunchy rings.
- In a small pot, combine the vinegar, water, salt, sugar, and any whole spices you're using, and bring the mixture to a boil over medium-high heat. Boiling fully dissolves the salt and sugar into the liquid, which is what creates an evenly seasoned pickling brine rather than one with gritty undissolved bits at the bottom.
- Add the sliced onions directly to the boiling brine and simmer for 30 to 60 seconds, stirring gently the whole time. This brief simmer softens the onion just enough and helps kick-start the color change to a vivid pink, without cooking the onion into mush — pull it from the heat while it still has some bite.
- Turn off the heat and let the mixture cool completely at room temperature before doing anything else with it. Cooling first prevents cracking a cold jar with hot liquid and gives the onions time to keep absorbing color and flavor as everything settles.
- Transfer the cooled onions and brine into a clean mason jar, tucking in any garlic cloves, bay leaves, fresh herbs, or jalapeño slices you're using among the onions as you go. Store in the refrigerator, where the pickled onions will keep well for up to 3 weeks.
Chef's Note: The vivid pink color that develops here isn't just visual — the hot vinegar brine breaks down the onion's cell walls just enough to release its natural pigments, which is also why slicing the onion paper-thin speeds up both the color change and how quickly the onion actually tastes pickled. It's a genuinely simple bit of kitchen chemistry that turns a sharp raw onion into something tangy, mellow, and worth keeping on hand.
If you swap the white vinegar for something milder like apple cider, rice wine, or red wine vinegar, cut the water by about 2 tablespoons to keep the brine strong enough for a full 3 weeks of fridge storage — white vinegar is more concentrated and also keeps the liquid clearest. This base recipe is endlessly adaptable: lean into cumin, coriander, and jalapeño for a Mexican-style version, dill and caraway for a Scandinavian twist, or fennel and curry leaves for an Indian-inspired jar.
A few tools that make this recipe easier to get right.
As an Amazon Associate, Salt & Simmer earns from qualifying purchases made through these links, at no extra cost to you.