Red onions have become one of my favorite ingredients because they can transform even the simplest recipes (see Thai Curry Vegetable Soup and Slow Cooker Coconut Curry Lentils), and there’s really no substitute for them.

The problem is I can rarely find red onions smaller than a softball and usually only require 1/4 or less of each onion in a recipe. To avoid wasting the rest, I always make a batch of pickled red onions.

Overhead view of a bowl of pickled red onions on a wooden plate with wooden bowls on the side

Exactly What Are “Quick” Pickles?

There are two methods of pickling vegetables: fermentation or vinegar brine. Both procedures use a salty, acidic liquid to prevent the growth of harmful bacteria.

In fermentation, the acid is produced by microorganisms, but this process can take days or even weeks. By contrast, store-bought vinegar produces this brine almost instantly, hence the name quick pickle.

In exchange for this quick process, quick pickles do not have probiotics, unlike fermented pickles, and their flavor can be more one-dimensional than fermented pickles.

Pickles that are fermented are more complex and may require some practice (here is a Fermented Sour Pickle recipe, if you are interested), whereas quick pickles are relatively straightforward.

What to Do with Pickled Red Onions

You can use pickled red onions on tacos, sandwiches, salads, pizza, nachos, flatbreads, avocado toast, and plenty more (basically any Mexican dish).

Rather than replacing fresh red onions with these pickled red onions, think of them as a non-spicy alternative to pickled jalapenos. The tangy pickled flavor goes great wherever pickled jalapenos are used.

How Long Will They Be Used?

You can keep pickled red onions in the refrigerator for 3-4 weeks if they are kept refrigerated and in the brine.

The flavor of the onions improves over time as they marinate in the brine.

Ensure that your pickled red onions are stored in an airtight, non-reactive container, such as a mason jar or other food-safe container.

Onions Can Be Customized

There are a million ways to make pickled red onions, but I have provided a very basic version below. As you make them more frequently, you can customize the flavors to your liking.

Try adding ingredients like bay leaf, star anise, sliced jalapenos, or red pepper flakes to the seasonings.

What Type of Vinegar to Use for Pickled Red Onions

In the recipe below, white vinegar is used, but you can use other kinds of vinegar to alter the flavor.

I suggest avoiding vinegar with strong flavors so they won’t overpower the onions.

You can pickle red onions using rice vinegar, white wine vinegar, red wine vinegar, or apple cider vinegar!

Pork tacos with pickled red onions
(Tacos made with Chili Rubbed Pulled Pork, pickled red onion, cotija and fresh jalapeño.)

Pickled Red Onions Recipe

The pickled red onion is a great way to use leftover red onions, and you can use it for tacos, sandwiches, pizza, and more.

Author: Beth

Prep Time: 10 mins / Cook Time: 5 mins / Soak Time: 30 mins / Total Time: 45 mins


  • 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)


  • 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.


*For onions that remain crunchy, pour the boiling vinegar over the onions in the bowl. If you prefer soft onions, add the onion and garlic to the sauce pot and allow them to boil in the vinegar for 1-2 minutes before transferring to a non-metal bowl to cool.


Serving: 1 recipe ・ Calories: 214.6 kcal ・ Carbohydrates: 53.4 g ・ Protein: 2.1 g ・ Fat: 0.3 g ・ Sodium: 3547.8 mg ・ Fiber: 3.5 g

The nutritional values shown here are only estimates. Please see our nutrition disclaimer.

Side view of a bowl of pickled red onions on a wooden plate

Step-by-step Photos on How to Make Pickled Red Onions

Sliced Red Onion on a green cutting board

In this recipe, you can use up to about 2 cups of sliced red onion, but you can use less if you have less on hand.

It is a great way to utilize a half onion, but I have used a whole onion for demonstration purposes. Slice the onion into 18-inch pieces.

Onions and garlic clove in a bowl
Slice the onions and peel one clove of garlic and place them in a large ceramic or glass bowl.
Salt, sugar, and peppercorns in a saucepot, vinegar being poured over top
Add ½ tsp whole peppercorns, 3 Tbsp sugar, 1.5 Tbsp salt, and 1 cup white vinegar to a sauce pot. Make sure all the salt and sugar are dissolved. Put the lid on the pot and heat it over medium-high heat.

Pour the boiling vinegar brine over the sliced onions and garlic in the bowl, stir gently to combine, and press the onions under the brine. Allow the mixture to cool to room temperature.

To help the onions stay below the brine, I like to place plastic wrap directly on the onions as soon as they become cool enough to handle.

Pickled red onions finished in a bowl
You’ll find the onions turn an incredible shade of pink as they soak in the brine. The pigment in red onions and red cabbage serves as a pH indicator. Isn’t it wonderful to learn about food science??
Overhead view of pickled red onions in a bowl on a wooden plate next to bowls of peppercorns and salt.
Whenever the onions reach room temperature and have a vibrant pink color, transfer them to an airtight container and refrigerate for up to 4 weeks. After a few days, the flavor becomes even more delicious!Three pulled pork tacos with pickled red onions and jalapeños.
(Tacos made with Chili Rubbed Pulled Pork, pickled red onion, fresh jalapeño and cotija.)