I love red onions because even just a few slivers of fresh red onion can truly transform a recipe (see Thai Curry Vegetable Soup and Slow Cooker Coconut Curry Lentils) and there’s no substitution that is really quite like it. BUT I can rarely find a red onion that is smaller than a softball and I usually only need 1/4 or less of it for a recipe. Because I hate to waste the rest of the onions, I always use the leftovers to make a batch of these Pickled Red Onions
What Are “Quick” Pickles?
There are two methods for pickling vegetables: through fermentation or by using a vinegar-based brine. Both methods use a salty and acidic liquid to prohibit the growth of dangerous bacteria. With fermentation, the acid is created by microorganisms, but this can take days or even weeks to accomplish. Store-bought vinegar creates this brine almost instantly, hence the name quick pickle.
The trade-off for this quick process is that quick pickles do not contain probiotics, like fermented pickles, and the flavor can be a little more one-dimensional. Fermented pickles are a bit more of an exact science and can take some practice to get right (here’s a recipe for Fermented Sour Pickles, if you’re interested), whereas quick pickles are pretty hard to mess up.
How to Use Pickled Red Onions
Pickled red onions are AWESOME on tacos, sandwiches, carnitas, salads, pizza, nachos, flatbread, avocado toast, burgers, and lots of other things (practically any Mexican dish). Instead of thinking of these pickled red onions as a substitute for fresh red onions, think of them as a non-spicy alternative to pickled jalapeño. That tangy pickled flavor tastes great anywhere you’d normally use a pickled jalapeño.
How long do They Last?
Keep your pickled red onions refrigerated and in the brine and they’ll last 3-4 weeks in the refrigerator! The flavor gets better over time as the onions marinate in the brine. Just make sure to keep your pickled red onions refrigerated in a non-reactive, air-tight container, like a mason jar or other food-safe storage container.
Customize Your Onions
There are a million different ways to make pickled red onions, so I’ve provided a very basic version below. As you begin to make them more often, you can start to tweak the flavors to match your preferences. Experiment with the seasonings and spices by adding ingredients like bay leaf, star anise, sliced jalapeño, or red pepper flakes.
What Kind of Vinegar to Use for Pickled Red Onions
The recipe below uses white vinegar, but you can use different kinds of vinegar in your pickled red onion recipe to change the flavor. I suggest not using vinegar with strong flavors so they don’t overpower the onions or the other ingredients. Try using rice vinegar, white wine vinegar, red wine vinegar, or apple cider vinegar in your pickled red onions!
(Tacos made with Chili Rubbed Pulled Pork, fresh jalapeño, pickled red onion, and cotija.)
Pickled Red Onions
Servings 10 1.5 cups totalIngredients
- 1.5 cups sliced red onion ($0.32)
- 1 clove garlic ($0.08)
- 3 Tbsp white sugar ($0.06)
- 1.5 Tbsp salt ($0.15)
- 1/2 tsp peppercorns ($0.05)
- 1 cup white vinegar ($0.06)
Instructions
- Thinly slice the red onion into 1/8-inch slices. Peel the garlic. Place the onion and garlic in a large glass or ceramic bowl.
- Add the sugar, salt, and peppercorns to a small sauce pot. Add the vinegar and stir until the sugar and salt are dissolved. Place a lid on the pot and bring the mixture up to a boil over medium-high heat.
- When it reaches a boil, pour the vinegar over the sliced onion and garlic.* Press the onion down so all the pieces are submerged, then let the mixture cool to room temperature. I sometimes place a piece of plastic wrap over the onions to help push and hold them below the surface of the brine (see step by step photos below).
- Once cool, use the onions immediately or transfer the onions and all the brine to a covered non-reactive container (glass, ceramic, or plastic) for storage in the refrigerator. The onions can be stored in the refrigerator for 3-4 weeks.
See how we calculate recipe costs here.
Notes
Nutrition
How to Make Pickled Red Onions – Step by Step Photos
This recipe works for up to about 2 cups of sliced red onion, but you can use less if you have less. It’s great for using up a leftover half onion, but I’ve used a whole onion for demonstration purposes here. Slice the onion into ⅛-inch slices.
Place the sliced onions and one clove of peeled garlic in a large ceramic or glass bowl.
Add 1.5 Tbsp salt, 3 Tbsp sugar, ½ tsp whole peppercorns, and 1 cup white vinegar to a saucepot. Stir to dissolve as much of the salt and sugar as possible. Place a lid on the pot and bring it up to a boil over medium-high heat.
Carefully pour the boiling vinegar brine over the sliced onions and garlic in the bowl. Stir to combine and press the onions below the brine. Allow the mixture to come to room temperature. I like to take a piece of plastic wrap and press it down onto the onions to help them stay below the brine just as soon as it’s cool enough to touch.
As the onions soak in the brine they’ll begin to turn an incredibly vibrant shade of pink. The pigment in red onions and red cabbage is a natural pH indicator. Don’t you just love food science??
Once the onions have come to room temperature and are a vibrant pink color, transfer them to an air-tight food storage container and refrigerate until ready to eat, or up to 4 weeks. The flavor gets even better after a few days!
(Tacos made with Chili Rubbed Pulled Pork, fresh jalapeño, pickled red onion, and cotija.)
I’ve been making your recipe for quite some time now. Not only am I in love with them but everybody I serve them to just raves. I I’ve actually had to send home jars with friends because they were so insistent. So I’ve taken to adding radish, celery and carrot. I love this recipe thank you so much for sharing.
i just made these and they are amazing! I do have one question though, how many servings would you say this makes? I’m adding the recipe into my fitness pal to figure out how many calories are per serving and i noticed it doesn’t say how many servings this recipe makes.
It depends on your taste really! When I make this it lasts us about 6 meals where it is a topping. That’s just for my husband and I.
This is an excellent recipe, I keep a jar in the fridge as a regular condiment. I’m plant based and always looking for a cheap easy way to add more flavor. I have used these on burgers, tacos, as a topper on bean chili, and in sandwiches.
These are so easy and delicious! We put them on lotsa stuff – wraps , sandwiches, salads, pizza, tacos, nachos, gyros, etc. Great way to preserve red onions for a month or more in the fridge. They’re not spicy, but rather are tangy, which is awesome :) My toddler gobbles them up
Great to keep people away at safe distance….eat onions to prevent coronavirus, by inducing bad breath and body odor. Joking….
Can you use coconut palm sugar instead?
Yes I’ve used coconut sugar with success!
This has been the recipe I’ve used most this year. I switched to apple cider vinegar because I like that better. I use this mix to pickle everything. Today: green apple, red onion, and jalapeno :)
You’re a rockstar DeAnna!
Super easy. Now i have a never ending supply of these ready to go!
I’ve been making them at least once a week for awhile now! Can’t stop!
I’ve done this twice and the picked onions are so good!! Just did another batch and doubled the recipe.
It’s a weekly staple here at our house!
Can you seal them in jars so they last longer? Not sure what that would do to them.
Canning requires a different process, and unfortunately I’m not experienced with canning so I can’t offer any help with that. :(
“If you don’t eat them all by then”.. you were not lying! I DEVOURED these – I cannot wait to make them again, and for family and friends to try them, as well. That is, if they even get a chance ;)
I absolutely love these onions. I’ve recently started Keto. Do you think a sugar substitute would work just as well? Or should I try with no sugar at all?
I definitely don’t think no sugar would be good because the sugar helps balance the flavors. I don’t ever use sugar substitutes, though, so I’m not sure how they would perform in this recipe.
Try lakanto monkfruit sweetener, it works great and has a zero glycemic index
Did you end up trying a sugar alternative? I’m also doing keto and would love to make these!
I used the soft onion method and they were wicked salty. I’d have to modify for sure. 1.5 T is too much, and I love salt.
I used Splenda and they tasted the same as when I’ve used granulated cane sugar
How many red onions would you plan for making tacos for 40 people
Oh wow, unfortunately I have no idea. I’m not very experienced (or experienced at all) with cooking for a crowd that size.
I’m one of those unfortunate souls who can’t abide raw onions–and to make it worse, DH adores them. I do, however love cooked onions; pickling does equally well in getting rid of the sulfurous taste of the raw ones and releasing their sweet flavor. This little recipe is genius–the onions are crunchy enough to keep DH happy and sufficiently processed for me to enjoy them, too. And I didn’t even mention how beautiful they are. There are tons of uses, mostly wraps, tacos, and other sandwiches, but they also dress up salads and garnish grilled meats. The color, even without the crunch and flavor, is wonderful to brighten up dull looking things like tuna salad.
You can pickle any onions, and if the color is important, a drop or 2 of red food coloring is an easy option. Jarred pickled Vidalias are available at my supermarket from a well known Southern brand–I think I will use this recipe for them as soon as they become available in a couple of months.
Amazing. Followed the recipe for soft onion. Very good. Thanks.