Quick Pickled Red Onions Recipe

I always keep Quick Pickled Red Onions in the fridge because this five-ingredient trick turns ordinary tacos, sandwiches, and burgers into something a bit more interesting.

I can’t stop tossing a jar of quick pickled red onions into everything these days. Thin red onion slices get this bright snap when I splash in apple cider vinegar, and suddenly tacos, sandwiches, even weeknight leftovers feel like they belong at a celebration.

It’s funny how a little tang makes you rethink an entire plate, you know? Friends always pause, take a bite, then go back for more like they just discovered a secret.

If you like bold contrast and crunchy zing, this is your new go-to. Think Pickled Red Onions Mexican Style that’s ready whenever you want it.

Ingredients

Quick pickled red onions are that bright, tangy pop you toss on tacos, salads, burgers or grilled cheese to wake up every bite.

They keep color and crunch, and they come together fast, so theyre perfect when you dont wanna fuss.

Onions bring fiber and antioxidants, vinegar adds sharp sourness and almost no calories, sugar softens the bite, and salt boosts flavor while helping texture.

This isnt fermented kraut style, just quick pickling that lives in the fridge for a few weeks.

Tiny jar, big payoff, seriously.

• Red onion: Crunchy, slightly sweet, source of fiber and antioxidants.
• Apple cider vinegar: Adds bright tang, low calories, may aid digestion.
• Water: Neutral liquid, dilutes vinegar, keeps pickles crisp.
• Granulated sugar: Balances acidity, adds sweetness, increases carbs.
• Kosher salt: Enhances flavor, preserves texture, contributes sodium.

Ingredient Quantities

• 1 large red onion, thinly sliced (about 1 1/2 to 2 cups)
• 1 cup apple cider vinegar (can use white vinegar if you want)
• 1 cup water
• 1 to 2 tablespoons granulated sugar
• 1 teaspoon kosher salt or fine sea salt

How to Make this

1. Peel and thinly slice 1 large red onion into paper thin rings, about 1/8 inch thick (should be roughly 1 1/2 to 2 cups once sliced). A mandoline makes this much faster, but a sharp knife is fine too.

2. Pack the sliced onion into a clean jar or container, pressing down so it fits snugly.

3. In a small saucepan combine 1 cup apple cider vinegar (or white vinegar if you prefer), 1 cup water, 1 to 2 tablespoons granulated sugar and 1 teaspoon kosher or fine sea salt.

4. Warm the mixture over medium heat, stirring, just until the sugar and salt dissolve and the liquid is steaming, not boiling, about 1 to 2 minutes.

5. Carefully pour the hot brine over the onions so they are fully submerged, press them down with a spoon or fork to remove air pockets.

6. Let the jar cool to room temperature, then close the lid and refrigerate. For quick pickles wait at least 30 minutes, for better flavor chill 1 to 4 hours or overnight.

7. Shake the jar once or twice the first day to redistribute the brine and make sure everything is submerged.

8. Store in the fridge for up to 2 to 3 weeks. If they taste too sharp, give them a quick rinse under cold water before using.

Equipment Needed

1. Cutting board — sturdy, big enough for a large onion
2. Mandoline or sharp chef’s knife (mandoline makes thin rings faster, be careful)
3. Paring knife or vegetable peeler for peeling the onion
4. Clean jar or airtight container with lid, about 16 oz or larger
5. Small saucepan for warming the vinegar brine
6. Measuring cups and measuring spoons (1 cup, 1 tsp, tbsp)
7. Heatproof spoon or wooden spoon for stirring and pressing onions down
8. Funnel or ladle to pour the hot brine without spilling
9. Oven mitt or kitchen towel for handling hot pot/jar

FAQ

Quick Pickled Red Onions Recipe Substitutions and Variations

• Red onion: swap for shallots (use 2–3 shallots for 1 large onion) or a sweet/vidalia or white onion for similar crunch, theyll be milder.
• Apple cider vinegar: use white vinegar (same amount) for a sharper bite, or rice vinegar for a gentler, slightly sweet flavor; red wine vinegar also works.
• Granulated sugar: replace with honey, maple syrup or agave — start with about 3/4 tablespoon liquid sweetener for each 1 tablespoon sugar and taste, or use brown sugar 1:1 for a deeper flavor.
• Kosher salt: if you only have fine table salt, use about half to three quarters the amount (so roughly 1/2 teaspoon table salt for 1 teaspoon kosher); pickling salt is another good swap since it dissolves cleanly.

Pro Tips

– Slice thin and even, seriously. If some rings are thick they’ll stay crunchy while the thin ones turn mushy, so use a mandoline or a very sharp knife and go slow, or wear a cut glove so you dont end up stapled to your onion.

– Heat the brine just till it steams and everything dissolves, dont boil it. Pour it hot so the onions soften and absorb faster, but let the jar cool a bit before tightening the lid so pressure doesnt build up.

– Tweak the sweet/tart balance by starting with 1 tablespoon sugar, taste after a few hours and add more if you want sweeter. Add little flavor boosters like peppercorns, a smashed garlic clove, or a strip of citrus peel for depth, but dont overload them or the onion flavor disappears.

– To keep them crisp, soak the sliced onions in cold water for 10 minutes before pickling, or store the jar on the fridge door so it gets disturbed less. If they ever taste too sharp, just rinse briefly under cold water before using.