Sugar-Free Quick Pickled Red Onions, an easy refrigerator pickled red onions recipe that is quick pickled in a no sugar vinegar brine. A tasty – and healthy – way to preserve your onion harvest!

side view of a jar of pickled red onions on a plate with onions, herbs and spices

Love pickled onions? So do we! This simple quick refrigerator pickled red onion recipe takes only 2 hours for the perfect pickled onions to use as toppings for burgers, salads, and tacos. We're using a homemade pickling brine that's free from sugar but big on flavor!

👉 Ready to learn how to quick pickle red onions without sugar? Let’s do it!

a plate containing red onions, water, oil, garlic, herbs and spices
Ingredients: red onions, vinegar, water, mustard, sugar, garlic, herbs

How to make (step-by-step photos)

1️⃣ Step One: Prep red onions

The first step is to wash and prep the red onions for pickling. To do this, simply cut the stems from the onion, slice it in half, and then remove the onion's outer layer.

Then cut each onion half into thin slices so you have very thin red onion strips that will easily soak up the pickling brine.

a cutting board with a knife and slices of red onions
Slice onions very thin

2️⃣ Step Two: Prepare the pickling jar

Next it’s time to prepare the jar that you will pickle the onion in. Choose a large, wide jar so that you can leave 1/2 inch of space after you fill the jar with the brine.

Add the red onion slices, dill (and other fresh herbs, if using), mustard seeds, garlic cloves, and red pepper flakes (optional, but we highly recommend).

overhead view of pickled red onions in a jar on a counter with herbs and spices
Prepare pickling jar

3️⃣ Step Three: Prepare and add the brine

You can't make pickled red onions without brine! This salted vinegar water is what adds the “pickled” flavor to vegetables and fruit.

Our go-to sugar-free refrigerator pickling brine formula is usually:

  • 1 cup water
  • 1 cup vinegar (distilled vinegar, white wine vinegar, and apple cider vinegar are our favorites)
  • 1 tablespoon salt

We increase or decrease the amount of brine depending on the amount of vegetables we’re pickling, but this is the foundational recipe we use that always produces great tasting pickled vegetables.

To make the brine:

  1. Add water, a vinegar of your choice (see our tips for vinegar below) and salt to a medium saucepan and bring to a boil.
  2. Pour the hot brine into the pickling jar and completely cover the onion slices, then close the lid tightly and allow it to cool down on the counter until it reaches room temperature.
a small sauce pan filled with water and apple cider vinegar brine on a stovetop with a wooden spoon
Boil the brine, the pour over vegetables

👉 Which vinegar should you use for pickling red onions? We like a sweeter vinegar for pickling onions to bring out their natural sweetness, so we opt for apple cider vinegar or red wine vinegar. You can also choose a milder vinegar like white wine or simple white vinegar as well.

bottles of red wine, white wine, distilled, rice, apple cider, and balsamic vinegars on a wooden table
Test out different vinegars to find your favorite brine recipe

4️⃣ Step Four: Refrigerate to quickly pickle the onions

Once the jar is cool, put the jar into the refrigerator and allow the onions to pickle in the vinegar brine.

sealed jar of pickled red onions on a platter

👉 How long to quick pickle red onions

If you want to serve quickly, let the red onions pickle for at least 2 hours. For best results, we recommend letting them soak up the brine for at least 24-48 hours.

The refrigerator pickled red onions are good up to one month in the refrigerator as long as they are submerged in the vinegar water.


❓ Questions and quick tips

What jar should I use for pickling red onions?

Choose a jar that's wide and tall enough to store the red onion slices. There should be about 1/2 – 1 inch (1-2 cm) of space between the slices and the lid so that they can completely submerge in the brine liquid.

How long before you can eat pickled red onions?

You can eat pickled red onions after they have been in the refrigerator for at least 2 hours. However, we suggest waiting for 24-48 hours for the best results. If your onions were sliced very thin, then less time will be needed for the best flavor.

How long do pickled red onions last?

As long as red onions are completely covered with brine, they will last for up to one month in the refrigerator. If any piece of the onions are sticking out of the water, there is potential for bacterial growth, so make sure to use a tall jar and to completely submerge them in the brine.

How do I know if my pickled red onions have gone bad?

Quick pickling vegetables and fruit does not come with the same food safety hazards as traditional pickling and canning. However, to make sure your onions stay safe while stored in the refrigerator, make sure to completely cover them in the liquid brine and to feel them before eating. If they're slimy, throw them out.

side view of a jar of pickled red onions on a plate with onions, herbs and spices

💡 Ideas for serving

Here are a few recipes and ideas to get you started:

  • On a pickable platter. Use pickled onions as a pickable snack on a large platter or board with assorted seasonal fruits, vegetables, nuts, seeds, crackers, and other pickled veggies.
  • As a condiment or topping. Grab a few pickled red onions and enjoy on top of a burger or tacos. It's a yummy switch-up from traditional pickles!
jar of pickled red onions on a plate with onions, oil, garlic, spices and herbs

🧅 More quick pickling recipes

Love quick pickling? Check out our other refrigerator pickling recipes:

Quick Pickled Red Onions (No Sugar!)

Sugar-Free Quick Pickled Red Onions, an easy refrigerator pickled red onions recipe that is quick pickled in a no sugar vinegar brine. A tasty – and healthy – way to preserve your onion harvest!
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Ingredients

  • 1 large red onion
  • ¼ cup dill, or other herbs
  • 2 single garlic cloves, sliced thin
  • 2 tablespoons mustard seeds
  • 1 teaspoon red pepper flakes, optional
  • 2 cups water
  • 1 cup vinegar
  • 1 tablespoon salt

Instructions 

  • Prep the red onion: Cut the stems off the red onion, then slice in half and remove the outer layer. Then slice each half into thin slices and set aside.
  • Prepare the pickling jar: Add sliced red onions to a large jar and add dill or other desired herbs, mustard seeds, garlic, and red pepper flakes.
  • Prepare and add the brine: In a medium saucepan bring the water, vinegar, and salt to a boil. Once boiling, pour into the jar until the liquid completely submerges the onions. Close the lid on the jar tightly.
  • Pickling instructions: Let the jar cool on the counter until it reaches room temperature. Once cooled, put the jar into the refrigerator and let the onions pickle for at least 2 hours before serving, but for best results serve after at least 24 hours. Quick pickled onions are good up to one month in the refrigerator.

Notes

  • Vinegar: Red wine vinegar and apple cider vinegar are the best vinegar choices for this recipe.
  • Recommended jar: Choose a large and wide jar with about 1/2 – 1 inch space (2-3 cm) below the lid.
  • Other recommended tools: small saucepan, cutting board, knife set
  • Prep ahead and storage: Refrigerator pickled onions should be made at least 2 hours before serving, but for best results make at least 24-48 hours ahead. Keep the jar refrigerated and it can be enjoyed for up to one month. Do not freeze.
  • Nutrition notes: Nutrition information is calculated with all brine ingredients (including full amount of sugar, salt, etc.), however the onions don’t absorb all of the liquid so the actual nutrition information is less than listed here.

Nutrition Information

Serving: 1serving, Calories: 18kcal, Carbohydrates: 2g, Protein: 1g, Fat: 1g, Saturated Fat: 1g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 1g, Sodium: 588mg, Potassium: 39mg, Fiber: 1g, Sugar: 1g, Vitamin A: 126IU, Vitamin C: 2mg, Calcium: 13mg, Iron: 1mg