There’s something irresistible about ruby-hued, tangy slices of Pickled Red Onions nestled in a cool jar. With a gentle sizzling as the brine hits the glass and a soft clinking of rings against the spoon, you know you’re onto something good. I’ve tested this recipe five times now—each batch teaching me more. In my third trial I discovered that hand-slicing yields a slightly rustic thickness that soaks up the brine perfectly, giving each bite a tender pop of flavor.
Why You’ll Love Pickled Red Onions
- Bright, tangy crunch that wakes up any dish without overpowering it
- Ready in under 10 minutes of hands-on time, then fridge-magic takes over
- Versatile topping for tacos, salads, sandwiches and more
- A simple nod to Middle Eastern and Mexican street-food traditions
A Little Background
My first brush with pickled red onions was at a taco stand in Echo Park. I came home determined to capture that glossy, rosy charm. After juggling jar sizes and adjusting the vinegar ratio in trial two, I finally landed on a fool-proof brine that’s bright yet balanced—rain or shine, summer or winter onions.
Key Ingredients for Pickled Red Onions
- Red onion: Provides crisp texture and vivid color; swap for white onion if needed, though the color will be milder
- Apple cider vinegar: Offers mellow tang; white wine vinegar works too but shifts the flavor slightly
- Water: Dilutes the vinegar for a balanced bite
- Sugar: Softens sharpness; can use coconut sugar for a deeper tone
- Salt: Draws out moisture and amplifies flavor; fine sea salt or kosher salt both do the job
How to Make Pickled Red Onions
- Thinly slice the red onion and place it in a clean, heatproof jar.
- In a small saucepan, combine the water, apple cider vinegar, sugar, and salt. Bring to a simmer over medium heat, stirring occasionally, until the sugar and salt dissolve (about 5 minutes).
- Carefully pour the hot brine over the onions in the jar, ensuring they’re fully submerged. Press down with a spoon if needed.
- Allow the jar to cool to room temperature (about 1 hour), then seal with a lid and refrigerate.
- The onions will be ready in about 30 minutes, but for best flavor, let them sit for 2–3 hours. Store in the refrigerator for up to 2 weeks.
Pro Tips & Troubleshooting
- Mandoline slicing gives even, wafer-thin rounds—perfect if you crave consistency.
- If onions float above the brine, tuck a citrus slice on top to weigh them down.
- Stir in a few peppercorns or a sprig of thyme for a seasonal twist.
- Scaling up? Double all ingredients for a quart-size jar; for half, simply halve each measurement.
Storage & Make-Ahead Guide
Once cooled, seal your jar tightly and keep it refrigerated at or below 40°F. I always label mine with the date—by day 10 I noticed a darker hue and softer snap, so I recommend using within two weeks. For food safety, use a sterilized jar (boil or dishwasher sanitize), and always use clean utensils to prevent contamination.
Serving Suggestions
Layer Pickled Red Onions on fish tacos for a bright crunch, scatter them over grain bowls, tuck into grilled cheese sandwiches, or serve alongside a cheese board for a pop of color and tang.
Frequently Asked Questions
- What are pickled red onions? Thinly sliced red onions preserved in a vinegar-based brine that softens their sharpness and adds tangy flavor.
- How long do pickled red onions last in the fridge? Properly stored below 40°F, they stay at peak quality for up to 2 weeks.
- Can you make pickled red onions ahead of time? Yes—prepare them a day in advance for even deeper flavor. They taste best after 2–3 hours in the fridge.
- Do pickled red onions need to be refrigerated? Always refrigerate after the brine and onions reach room temperature to ensure safety and freshness.
- Can I use other types of onions for pickling? You can, but red onions offer the ideal color and sweetness. White or yellow onions will taste sharper and look paler.
- How do I use pickled red onions in recipes? Add them to tacos, salads, sandwiches, burgers, grain bowls, and more for a bright, acidic counterpoint.
Final Thoughts
Pickled Red Onions are one of my favorite quick-pickles—they add zing and color to almost anything with minimal effort. I can’t wait to hear how you use them—drop a comment or snap a photo and share your results!
More Recipes You’ll Love
- Marinated Cherry Tomatoes – similarly tangy veg that brightens any plate
- Birria Tacos – warm, savory tacos that pickled red onions top beautifully
- Smoked Chicken Thighs – rich, smoky meat cut through by crisp, acidic onions
- Crispy Fish Tacos with Cilantro Lime Slaw – pairs crunchy fish with cool slaw and pickled onion zing
Pickled Red Onions
Ingredients
Pickling Brine
- 1 cup water
- 1 cup apple cider vinegar
- 1 tablespoon sugar
- 1 teaspoon salt
Onions
- 1 large red onion thinly sliced
Instructions
Pickling Process
- Place the sliced onion into a clean, heatproof jar.
- Combine water, apple cider vinegar, sugar, and salt in a small saucepan and bring to a gentle simmer over medium heat, stirring until sugar and salt dissolve.
- Carefully pour the hot brine over the onions, ensuring they are fully submerged.
- Let the jar cool to room temperature before sealing with a lid and refrigerating.