I always keep these quick pickled red onions in my fridge because they instantly add tang, crunch, and a pop of color to any meal. They are sweet, slightly sharp, and wonderfully crisp, and I love how easy they are to prepare with just a few basic ingredients. Whenever I need to brighten up a dish, this recipe is my go-to.
Why You’ll Love This Recipe
I love this recipe because it is incredibly fast and requires almost no effort. I can make it in minutes, and the onions taste amazing even on the same day. I also enjoy how flexible it is, since I can easily adjust the sweetness, acidity, or spice level to match my mood. These onions make simple meals feel special and homemade without much planning.
Ingredients
(Tip: You’ll find the full list of Ingredients and measurements in the recipe card below.)
2 medium red onions, thinly sliced
1 ¼ cups water
1 ¼ cups white vinegar
3 tablespoons sugar of choice
1 tablespoon sea salt
¼ to ½ teaspoon red pepper flakes (optional)
Directions
I begin by heating the water in a small saucepan until it is hot but not boiling, then I remove it from the heat. While the water heats, I thinly slice the red onions into rings or half-moons and place them into a large glass jar.
Next, I add the sugar, salt, vinegar, and red pepper flakes to the warm water and stir until everything is fully dissolved. I pour this mixture over the onions, making sure they are completely submerged. I gently press them down, seal the jar, and let it cool slightly before placing it in the refrigerator. I usually let the onions sit for at least 30 minutes, but I prefer the flavor after they marinate overnight.
Servings And Timing
This recipe makes about 16 servings, with one serving equal to roughly one tablespoon. The preparation time is about 10 minutes, and there is no cooking time involved. Although the onions are ready to eat after 30 minutes, I find they taste best after resting in the fridge overnight.
Variations
I often customize these pickled red onions depending on what I am serving them with. Sometimes I add whole spices like peppercorns, mustard seeds, or coriander seeds for extra flavor. Fresh herbs such as thyme or bay leaf are also great additions. When I want more heat, I add sliced chili instead of red pepper flakes. For a sweeter and milder version, I reduce the vinegar slightly and add a bit more sugar.
Storage/Reheating
I store the pickled red onions in a sealed glass jar in the refrigerator. As long as the onions stay fully submerged in the brine, they keep well for up to two weeks. I never reheat them, since they are meant to be enjoyed cold or at room temperature.
FAQs
How thin should the onions be sliced?
I like slicing the onions very thin so they pickle quickly and stay crisp, but slightly thicker slices work if I want more crunch.
Can I make them less sharp?
If I want a milder flavor, I briefly blanch the sliced onions in hot water before pickling them.
Can I adjust the sweetness?
I often adjust the sugar based on my taste. Adding more sugar makes the onions sweeter, while reducing it creates a sharper, more tangy flavor.
Do I need a special jar?
I always use a clean glass jar with a tight lid. There is no need for special equipment since these are stored in the fridge.
How soon can I eat them?
I usually start eating them after 30 minutes, but I think they taste best after sitting overnight.
Conclusion
I love how these quick pickled red onions bring bold flavor to everyday meals with very little effort. They are simple to prepare, easy to customize, and incredibly versatile. Once I started making them regularly, they became a staple in my kitchen that I always enjoy having on hand.
These quick pickled red onions are tangy, slightly sweet, and crisp—perfect for adding flavor and color to salads, tacos, sandwiches, and more. Made with simple ingredients in just minutes, they’re a fridge staple.
Ingredients
2 medium red onions, thinly sliced
1 1/4 cups water
1 1/4 cups white vinegar
3 tablespoons sugar
1 tablespoon sea salt
1/4 to 1/2 teaspoon red pepper flakes (optional)
Instructions
Heat the water in a small saucepan until hot but not boiling, then remove from heat.
Thinly slice the red onions and place them in a clean glass jar.
Add sugar, salt, vinegar, and red pepper flakes (if using) to the warm water and stir until fully dissolved.
Pour the brine over the onions in the jar, pressing them down so they are fully submerged.
Seal the jar, let it cool slightly, then refrigerate.
Let the onions sit for at least 30 minutes before using. For best flavor, refrigerate overnight.
Notes
For added flavor, try adding whole spices like peppercorns, mustard seeds, or bay leaves.
Use sliced chili for extra heat instead of red pepper flakes.
Adjust sugar and vinegar to taste for a milder or sweeter brine.
Use a clean glass jar with a tight-fitting lid for storage.
No need to reheat—enjoy cold or at room temperature.
