Pickled Red Onions are a sweet and sour addition that will take any dish up a level. This simple recipe only needs thinly sliced onion and a few kitchen staples to make a pickling solution, then the refrigerator does the work while everything sits overnight. You’ll be enjoying these easy onions on your favorite sandwiches, salads, and SO many other dishes.
There is this quaint little taco shop I ate at 3 days in a row when visiting Asheville, North Carolina.
The thing that made their tacos so good?
Nearly EVERY single one of them had some type of pickled veggie on top.
Pickled red onions!
So as soon as I got home I set to work transforming this Refrigerator Dill Pickles recipe into one that would work with thinly sliced onions.
Whisking up a homemade pickling brine, tossing in some garlic, dill, and pickling spice, and voila!! The BEST homemade pickled red onions were born.
But what’s even better? They were perfectly pickled and ready to enjoy within the next 12 hours!
The simple ingredients you need to make this Pickled Red Onion recipe include:
- Red onion. You will need 1 medium-sized onion that is relatively fresh.
- Vinegar. For that classic pickle taste, opt for distilled white vinegar. However, you can use apple cider vinegar, but note that the flavor will definitely be affected. Do not use rice vinegar as the flavor won’t be the same.
- Water. Not all of the solution is acidic, the water helps to balance out the vinegar so it’s not too sour.
- Salt. The key to a good brine is salt. You can get pickling salt at most stores, but table salt can work, as well. Start with a modest amount, then increase or decrease depending on your preference.
- Sugar. You need just a touch to offset the tartness of the vinegar. Adjust the amount to your preference.
- Optional Ingredients. The sky is the limit! Toss in some fresh dill (if you have dried, be sure to use less!), whole garlic cloves, or pickling spice.
How to Make Pickled Red Onions
Below you’ll find the steps to follow to make this Pickled Red Onion recipe:
Perfect Pickling Brine
To make pickled onions, you first need to make the solution.
Add vinegar, salt, sugar, and water to a medium saucepan. Bring the mixture to a boil over high heat. Then, reduce the temperature to low. Simmer the vinegar solution for 2 to 3 minutes. Be sure to stir it occasionally.
It is important not to heat the liquid for too long or you will reduce the amount to a point where you don’t have enough left. You just barely want to let the sugar and salt dissolve.
Slice the Onions
You can cut an onion in a couple of different ways. The best option is to use a mandoline as the pieces will be thinner and soak up the solution beautifully.
Otherwise, simply use a sharp knife and a cutting board.
First, cut each end of the onion off, then slice it in half between the removed ends. From this point, it should be easy to peel away the flaky, outer layer.
Place the flat side of the onion down on the cutting board. Carefully make thin slices, to about ⅛-inch thickness, working from one edge to the other. The result will be tiny, thin half moons.
Fill the Jars
Once the onions are sliced and the pickling solution is made, it’s time to fill the jars. If you want to add flavors, do that first. Place garlic cloves, fresh dill, black whole peppercorns, or even a homemade pickling spice in the bottom of the container.
Place the sliced onions on top of the other items. Pour the warm pickling solution over the vegetables and allow it to come to room temperature. If there is any space left, fill with water to top the jar off.
Cover and Store
Wipe the rim of the jar with a towel and securely screw the lid on top.
Place the pickled onions in the fridge. Allow them to rest for at least 4 hours, but they will be even more delicious the next day.
Meal Prep and Storage
- To Prep-Ahead: This recipe is best made ahead of time! You can make these pickles at least four hours or up to several days in advance.
- To Store: The onions will last in the refrigerator in an airtight jar for up to 2 to 3 months. After about a month, they will lose some flavor.
- To Freeze: Place the pickled onions in a freezer-safe container. They will be good frozen for up to 6 to 8 months. Drain the pickling solution first, though.
Pickled red onions are delicious on so many things! Try them on your favorite Mexican dish, like burritos, quesadillas, enchiladas, or a bowl. They are great on sandwiches and burgers, or in sides like potato salad.
Pickled red onions keep for up to 2 to 3 months in the fridge. If you don’t process the jar, these will not be shelf stable and must be kept in the refrigerator.
You can absolutely add pickled red onions into just about anything you’re cooking! They make everything better with their sweet and sour flavor.
There are so many flavors to add to pickled onions. Try adding fresh herbs like rosemary, oregano, or thyme. Cinnamon, star anise, clove, and allspice will create a warm, fall feel in the onions. Or, put in a sweetener like honey or pure maple syrup, if you prefer.
Expert Tips and Tricks
- Keep it short. Do not boil the vinegar solution for too long or you won’t have enough left!
- Slice ’em thin. Be sure to cut the onion as finely as possible so the pieces can soak up as much bringing solution as possible.
- Let it cool. Set the vinegar mixture aside while you cut the onions so the temperature can chill slightly before pouring it over the onions.
- Top it off. If the brining solution doesn’t cover the onions, add water to finish filling the jar.
- Change it up. Get creative with the flavors and experiment with different additions, like herbs, sweeteners, or even other veggies like jalapeños.
Ways to Use Pickled Red Onions
These pickled red onions are absolutely delicious in these dishes:
- Sheet Pan Nachos
- Italian Dressing Pasta Salad
- Sweet Potato and Black Bean Burger
- Air Fryer Hamburger
- Shredded Chicken Enchiladas
More Quick Pickled Vegetable Recipes
Once you see how easy it is to pickle vegetables, try one of these recipes next:
- Pickled Carrots
- Pickled Beets
- Pickled Garlic
- Pickled Beets
- Pickled Radishes
- Overnight Refrigerator Pickles
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- 1 small red onion thinly sliced
- ⅔ cup distilled white vinegar
- ⅓ cup water
- 1 ¼ tsp. salt
- 1 Tbsp. sugar
- Pickling spice red pepper flakes, garlic, and/or dill, optional
- Add vinegar, water, salt, and sugar to a saucepan over high heat. Bring to a boil and then reduce heat to low. Simmer for 2-3 minutes, whisking occasionally, or until the salt and sugar have dissolved.
- Add the red onions to a 16-oz. mason jar along with pickling spice, red pepper flakes, garlic, and/or dill, if using.
- Pour the warm solution over the red onions and let cool to room temperature. If there is any space left in the jar, pour additional water in until it just reaches the top.
- Cover the jar with a lid and store in the refrigerator for at least 4 hours or up to overnight before enjoying.
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Meal Prep and Storage
- To Prep-Ahead: This recipe is best made ahead! You can make these pickles at least four hours or up to several days in advance.
- To Store: These onions will last in the refrigerator for up to 2 to 3 months.
- To Freeze: Place the pickled onions in a freezer-safe container. They will be good frozen for up to 6 to 8 months.
- To Reheat: Allow this dish to thaw in the fridge before serving again.
Nutrition information is automatically calculated, so should only be used as an approximation.