Balsamic Pickled Onions

They’re a great addition to a variety of dishes to add a pop of flavor and texture.

Enjoy them in rice bowls, salads, burgers, or sandwiches.  Try them on sweet potato chickpea tahini salad, vegan strawberry spinach salad, or a hummus cucumber sandwich. For more easy recipes for quick pickles try spicy pickled onions or pickled white onions.

Recipe features

• The recipe uses simple ingredients!
• Great for meal prep!
• An easy way to add a burst of flavor to dishes!
• Customizable!
• They can be stored for weeks in the refrigerator in an airtight container!

Ingredient notes and substitutions

The recipe uses simple ingredients, but please see the recipe card below for the full list of ingredients and the exact measurements.

Red onion - I mainly stick to pickling red onions since they have a milder flavor compared to yellow or white onions.  If you need to substitute, a white onion or a sweet variety like a Vidalia should work.

Balsamic vinegar - This is the predominant flavor in these pickled onions to give them a sweet, rich, and tangy flavor.  You may want to adjust the sweetness based on how sweet your balsamic tastes and your preference.  There is a wide range of balsamic brands on the market and they are not all the same.  I would opt for a cheaper brand with this recipe and reserve the more expensive ones for something else.

White vinegar - The recipe calls for a combination of balsamic and white vinegar to make these quick pickled red onions.  Quite simply put, during testing I didn’t think using all balsamic vinegar had a big enough difference in flavor versus cutting it with a cheaper vinegar.  White distilled vinegar and apple cider vinegar both work. 

Cane sugar - Customize the recipe to your preferences, I prefer these a little sweeter than my other recipe for spicy pickled red onions.  Maple syrup can also be used, it will make the pickles slightly less sweet compared to using cane sugar.

Salt - To help round out the flavor.

Oregano or rosemary- Both herbs have their distinct flavor profile giving the pickled onions a unique flavor.  I tested with both dried oregano and a sprig of fresh rosemary and enjoyed both options so I wanted to include both options for you as well.

A fresh rosemary sprig does give the onions a stronger more pronounced flavor compared to using dried oregano.  The dried oregano will give the onions a less intense herby flavor and it’s easy to keep on hand to have almost everything in the pantry to make these balsamic onions.

Peppercorns - Add whole peppercorns for a hint of peppery kick.

Tips

• The balsamic pickled onions are ready when the liquid cools, but leaving them overnight in the fridge gives the onions a longer time to soften and reduces the strong onion flavor.
• Boil the water, vinegar, sugar, and salt to dissolve the sugar and salt in the hot liquid.  This method also softens the onions much quicker.
• Keep the onions below the liquid. 
• This recipe is very forgiving.  Add more sugar for a sweeter version or more salt to make them even saltier.
• A mandoline can be used for very thin uniform slices.
• Use a jar that’s at least 28 ounces (850 mL).
• If the onions stick out after you pour the hot liquid on top of them, let them soften and then push them down to submerge them in the liquid.  

How to make pickled onions in balsamic vinegar

Start the pickled onions by peeling and thinly slicing the onion.  Add the onion slices, dried oregano (or rosemary), and peppercorns to a clean jar.  Use a nonreactive heat-proof container, we use a wide-mouth large glass jar.

The recipe is very forgiving.  Use more sugar for a sweeter version or more salt to make them even saltier.  Combine balsamic vinegar, white vinegar, water, sugar, and salt in a small saucepan.  Bring to a gentle boil on medium-high heat. 

Once boiling, lower the temperature to low.  Stir to help dissolve the sugar and salt.  Only simmer until the sugar and salt dissolve, which won't take long. They'll probably already be dissolved by the time the liquid comes to a boil. Don't continue boiling, otherwise you may lose too much liquid.

Then carefully pour the hot pickling liquid into the glass jar, covering the sliced red onion. Let the onions cool to room temperature before covering them with a lid and storing them in the refrigerator.  They’re ready once they have cooled, but they taste better and are softer after soaking for 24 hours.

Serving suggestions

Our favorite way to enjoy these pickled balsamic onions is to add them to grain bowls, but they add a punch of flavor to so many dishes.  Here are a few suggestions.

• Enjoy them on Buddha bowls or grain bowls.  Try them on a butternut squash Buddha bowl or maple mustard tempeh Buddha bowl.
• Use them as a topping for sandwiches like hummus cucumber sandwiches.
• Top veggie burgers with them.
• Add them to a falafel bowl with couscous or rice, olives, cucumbers, broccoli, greens, and hummus.
• Top vegan toast or vegan avocado toast.
• Add them to salads, like strawberry spinach salad with avocado or chickpea sweet potato tahini salad.

Storage

The quick pickled onions can be stored for about 2 weeks in an airtight container in the refrigerator.  Keep the onions submerged in the vinegar brine.  Use a small piece of parchment paper between the lid and the jar in case the lid starts to rust.  We use a heat-proof wide-mouth glass jar to store the onions.

Frequently asked questions

Related recipes

• Pico de gallo
• Pickled radishes

I hope you enjoyed the recipe!  If you did feel free to rate it and leave a comment!