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This is the condiment I reach for when a grilled burger or a weeknight taco needs something sharp and crisp. It takes about twenty minutes of actual work, then the fridge does the rest. The hardest part is waiting a full day before you open the jar.
I started making this relish every summer when the pepper plants went wild and the onion bin was overflowing. A quick brine of vinegar, sugar, and whole spices softens the bite of raw onion without turning everything mushy. What you get is a bright, sweet-tangy mix that keeps for weeks and improves by the day.
The pepper and onion lineup
Fresh bell peppers give the relish its color and crunch, so buy the firmest ones you can find. I like a mix of red, yellow, and orange for sweetness, but green works if you want a slightly sharper edge. A fresh white or red onion provides the savory backbone.
- Mixed bell peppers. They bring sweetness, crunch, and that jewel-box color that makes the jar look as good as it tastes.
- Yellow or white onion. Sliced thin, it pickles quickly and adds a savory depth that balances the sugar.
- White and apple cider vinegar. The white vinegar gives clean acidity, while apple cider vinegar adds a subtle fruity roundness.
- Granulated sugar. It tames the sharpness of the vinegar and helps the vegetables keep their snap.
- Whole mustard seeds and celery seeds. Tiny flavor bombs that give each bite a warm, slightly peppery pop.
- Turmeric and black pepper. Turmeric lends a gentle earthiness and a golden tint, and pepper adds a quiet heat.
- Red pepper flakes. Optional, but they wake everything up if you like a little fire.
Build the brine and pour
- Slice the vegetables. Cut the peppers and onion into thin strips or half-moons, no thicker than a pencil. Thin slices pickle evenly and stay crisp.
- Make the spiced brine. Combine both vinegars, sugar, mustard seeds, celery seeds, turmeric, salt, black peppercorns, and red pepper flakes in a medium saucepan. Bring to a boil and stir until the sugar dissolves completely.
- Pour and cool. Place the sliced vegetables in a large heatproof bowl. Pour the boiling brine over them and stir to coat every piece. Let the mixture cool to room temperature.
- Jar and chill. Transfer the relish and all its liquid into clean glass jars. Refrigerate for at least 24 hours before eating so the flavors can fully meld.
Why thin slices matter
Thick chunks of pepper or onion take days to pickle through and stay harsh and crunchy in the center. Slicing everything thin means the hot brine penetrates in minutes, not hours. The vegetables soften just enough to lose their raw bite while keeping a pleasant snap. If you have a mandoline, this is the time to use it. A sharp chef's knife works fine too. Just keep the slices uniform.
Swaps and heat levels
You can change the vinegar balance to suit your taste. All white vinegar makes a brighter, more assertive relish. All apple cider vinegar leans sweeter and mellower. Honey or maple syrup can replace half the sugar for a deeper sweetness, though the color will darken slightly. For heat, swap one bell pepper for a thinly sliced jalapeno, or add a pinch more red pepper flakes. If you enjoy other pickled condiments, our quick and easy zesty pickled sweet peppers and onions uses a similar technique with a slightly different spice blend.
Storing and shelf life
Keep the relish in clean glass jars with tight lids in the coldest part of your refrigerator. It stays crisp and flavorful for up to three weeks. The brine may darken a little as the vegetables age, but that is normal. Always use a clean spoon to scoop out what you need so you do not introduce bacteria into the jar. For another quick pickle to keep on hand, try our quick pickled garden vegetables.
Ways to serve it
Pile it onto grilled burgers, brats, or hot dogs straight from the jar. It also works as a bright topping for tacos, a crunchy addition to rice bowls, or a tangy contrast on a cheese board next to sharp cheddar. I have even stirred it into tuna salad for a sweet-and-sour twist. If you want something fruitier to pair with grilled meats, our pepper jelly is a good companion.
FAQs
- Can I use different colored bell peppers?
Yes. Red, yellow, and orange bells are the sweetest. Green bell peppers give a slightly sharper, more vegetal edge. A mix of colors looks beautiful in the jar and gives you the most complex flavor.
- How long does pickled pepper and onion relish last?
Stored in a clean glass jar with a tight lid in the refrigerator, the relish stays crisp and tasty for up to three weeks. Always use a clean spoon to avoid introducing bacteria.
- Can I reduce the sugar?
You can cut the sugar by about one third, but the relish will taste sharper and the texture will be slightly less crisp. Honey or maple syrup are good natural alternatives that add their own depth.
- Do I need to can this relish?
No. This is a refrigerator pickle, not a shelf-stable canned product. It does not require a water bath or pressure canner. Just keep it cold. For safe pickling guidance, the National Center for Home Food Preservation offers excellent resources.
- Can I freeze leftover relish?
Freezing is not recommended. The high water content in peppers and onions causes them to turn soft and lose their snap once thawed. This relish is best kept in the refrigerator.
- What should I do if the brine tastes too sharp?
Stir in an extra teaspoon of sugar and let the jar rest another day. The flavors mellow and round out significantly after the first twenty-four hours in the fridge.
