Quick Pickled Red Onions (Paleo, Whole30, Vegan)

These quick pickled red onions add a tangy crunch to all of your favorite dishes, from burgers to salads! Sweetened only with apple juice, these pickled onions are Whole30-friendly, paleo, and vegan!

One of the easiest ways to jazz up a boring dish is to top them with zingy, crunchy pickled red onions. It’s my secret weapon for making leftovers taste like bestovers!

Thin rings for the win! 

Use a mandolin (like a cheap Japanese Benriner) or sharp knife to cut the red onions crosswise into thin rings that are a little less than ¼-inch thick. This way the onion rings will pickle faster, and the thinner slices allow you to control the amount of pickle-y goodness you add to your dishes!

Use high quality vinegar and juice!

My favorite types of vinegar to use in this recipe are apple cider vinegar and rice wine vinegar. Both are not super sharp and add the right balance of acidity to these pickled onions. In terms of apple juice, my favorite brand is Martinelli’s because it tastes the best in my humble opinion. No apple juice? Grape juice also works!

Pickled onions taste best the next day!

Although these quick pickled red onions only take a few minutes of hands-on time to throw together and you can eat them as soon as 30 minutes after you dunk them in the brine, I think they taste the best after chilling in the fridge for a few hours. Overnight, the pink onions are pliable and have an acidic bite!

What else can you quick pickle?

You can pickle other vegetables, like thinly sliced Persian or English cucumbers, slivered carrots, or even thinly sliced daikon! Also, you can add different flavors to the brine like red pepper flakes, crushed garlic cloves, peppercorns, or fresh herbs. Start experimenting with a bunch of different flavor boosters and you’ll end up with a variety of quick pickles!

Can you make them with a keto sweetener?

These quick pickled onions are way too tart if you leave out the juice or something sweet to balance out the acidity. Although I don’t use a lot of sugar substitutes, some readers have told me that they have used keto sweeteners like monk fruit, stevia, allulose, and erythritol with success. Each sweetener is a different, so add to taste!

How to make quick pickled red onions

Combine the apple cider vinegar, juice, and salt in a measuring cup and whisk well.

Pack the thin onion slices into a small jar. I like these wide-mouthed Weck jars.

Pour the brine over the onions and use a fork to submerge the onions completely.

Cover and set aside in the refrigerator for at least 30 minutes before diving in!

Put them on all the things!

What dishes can you top with them?

These quick pickled red onions taste great on any savory dish that needs a bracing tangy crunch! I love to throw them on top of burgers, tacos, and even salads. Zingy onions are the perfect contrast to heavier meat dishes so they pair perfectly with Instant Pot Kalua Pig, Potsticker Stir-Fry (a.k.a. Egg Roll in A Bowl), and even Fiona’s Phenomenal Green Chicken!

How long do they keep in the fridge?

If you don’t manage to finish these pickles in a couple of days, you can keep them in a sealed container in the fridge for up to a week. These pickles aren’t fermented or pressure canned so mold will grow on them if you keep them longer!