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These balsamic pickled onions are sweet, tangy, and full of rich balsamic flavor. Thinly sliced red onions soak in a hot brine made with balsamic vinegar, white vinegar, sugar, salt, and herbs for an easy condiment with only about 10 minutes of hands-on preparation.
The balsamic gives the onions a deeper, slightly sweeter flavor and darker color, while the white vinegar adds enough brightness to balance the brine. Unlike regular pickled onions, which taste sharper and often turn bright pink, these have a deeper, slightly sweeter flavor and darker color.
They're ready once cooled, but letting them pickle overnight softens the slices, mellows the raw onion flavor, and gives them more time to absorb the sweet and tangy brine. Keep a jar in the refrigerator to add flavor and crunch to rice bowls, salads, sandwiches, veggie burgers, or avocado toast. For more quick pickle recipes, try my spicy pickled onions or pickled white onions.
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Recipe features
- Quick and easy: Only about 10 minutes of hands-on preparation.
- Sweet and tangy: Balsamic and white vinegar create a rich, balanced brine.
- Easy to customize: Adjust the sweetness or choose oregano or rosemary for a different flavor.
- Great for making ahead: They're ready once cooled, but become softer and more flavorful after 24 hours.
Ingredient notes and substitutions
The recipe uses simple ingredients. See the recipe card below for the full list and exact measurements.
Red onion - Red onions have a mild flavor that works well for pickling. White onions or sweet varieties, such as Vidalia, can also be used.
Balsamic vinegar - This gives the onions their rich, tangy, and slightly sweet flavor. Balsamic vinegars vary in sweetness, so you may need to adjust the sugar to taste. An inexpensive, pourable balsamic works well for this recipe. Avoid thick, aged balsamic varieties because they will not create a suitable brine for pickling. Do not substitute balsamic glaze, which is thicker and sweeter.
White vinegar - Adds a brighter tang that balances the sweetness and richness of the balsamic. During testing, an all-balsamic brine did not add enough extra flavor to justify the additional cost. Distilled white vinegar works well, or you can substitute apple cider vinegar.
Cane sugar - Balances the acidity and adds sweetness. I prefer these pickled balsamic onions a little sweeter than my spicy pickled red onions, but you can adjust the amount to suit your taste. Maple syrup can also be used.
Salt - Enhances and balances the other flavors in the brine.
Oregano or rosemary - I tested the onions with both dried oregano and a sprig of fresh rosemary and enjoyed each option. Dried oregano adds a mild herby flavor and is convenient to keep on hand, while fresh rosemary gives the onions a stronger, more pronounced flavor. Choose whichever flavor you prefer.
Peppercorns - Add whole peppercorns for a subtle peppery bite.
How to make pickled onions in balsamic vinegar
1. Prepare the onions. Peel and thinly slice the red onion. Add the slices to a clean, wide-mouth glass jar or another nonreactive, heat-safe container. Add the peppercorns and either oregano or rosemary.
2. Make the brine. Combine the balsamic vinegar, white vinegar, water, sugar, and salt in a small saucepan. Bring to a gentle boil over medium-high heat, stirring until the sugar and salt dissolve. Remove it from the heat promptly so that too much liquid does not evaporate.
3. Pour over the onions. Carefully pour the hot brine into the jar, making sure the onions are covered. Gently press them down once they have softened, if needed, to ensure they are covered.
4. Cool and refrigerate. Let the onions cool to room temperature, then cover the jar and refrigerate. They are ready to eat once cooled, but after 24 hours, the sharp onion flavor mellows, the slices soften, and they absorb more of the sweet and tangy brine.
Tips
- Let them pickle overnight. The onions are ready once the brine has cooled, but refrigerating them for 24 hours gives them time to soften and mellows the sharp onion flavor.
- Slice the onions evenly. Thin slices soften and pickle faster; use a mandoline if you prefer more uniform slices.
- Adjust the sweetness. Balsamic vinegars vary in sweetness, so taste yours before using it and adjust the sugar to suit your preference.
- Use a large enough jar. A wide-mouth jar that holds at least 32 ounces or 950 mL works well for one large 400-gram red onion.
Troubleshooting balsamic pickled red onions
- Too sharp or raw-tasting? Let the onions pickle for a few more hours or overnight. Thin slices soften faster than thick ones.
- Too sweet? Add a small splash of white vinegar. Use less sugar next time.
- Too tangy? Stir in a little more sugar, then let the onions sit for 30 minutes before tasting again.
- Not enough brine? After pouring the hot brine over the onions, let them sit for a few minutes to soften. If there is still not enough brine, top it off with more balsamic vinegar and white vinegar.
- Too much balsamic flavor? Add a little more white vinegar and water to mellow it.
- Cloudy brine? The seasonings or onions may cause slight cloudiness. Discard the batch if you notice mold, an unpleasant or yeasty odor, unexpected bubbling, or a slimy texture.
Serving suggestions
Our favorite way to use these balsamic pickled onions is on grain bowls, but they add a sweet and tangy bite to many dishes.
- Bowls: Add them to a hummus bowl, a butternut squash Buddha bowl, a maple mustard tempeh Buddha bowl, or a falafel bowl.
- Sandwiches and burgers: Use them on hummus cucumber sandwiches or veggie burgers.
- Toast: Spoon them over vegan toast, avocado toast, or toast with avocado and tomato.
- Salads: Add them to strawberry spinach salad or chickpea sweet potato tahini salad.
Storage
Store quick-pickled onions in an airtight container in the refrigerator for about 2 weeks. Keep the slices submerged in the brine and always use a clean utensil to remove them. A heat-safe, wide-mouth glass jar works well. If using a metal lid, use a small piece of parchment paper between the lid and the jar in case the lid starts to rust.
Balsamic vinegar pickled onions FAQs
Quick pickles, also called refrigerator pickles, are vegetables soaked in a vinegar-based brine that are not shelf-stable. They must be kept refrigerated.
No, balsamic glaze is thicker and sweeter than store-bought balsamic vinegar, so it will not create the same brine or pickled flavor.
Yes, but the flavor and color will be different. White balsamic vinegar is milder and lighter, so the onions will taste less rich, and the brine will not develop the same dark color but will still turn pink from the red onions.
I haven't tested this recipe for canning, so I can only recommend refrigerating these balsamic pickled onions. For shelf-stable canning, use a research-tested pickled onion recipe from a trusted canning source.
Yes, slice the onions very thinly and refrigerate them in the cold brine for at least 24 hours. They will be more crisp than onions made with hot brine and may need more liquid to remain submerged.
To determine how much brine you need, cover the onions with water, then drain only the water into a liquid measuring cup. Use that measurement as the total amount of brine needed, with half water and half vinegar. Divide the vinegar portion between balsamic and white vinegar using the same proportions as the recipe.
Add the measured water and vinegars to the jar with the onions, along with the sugar, salt, herbs, and peppercorns from the recipe card. Cover and shake well, then refrigerate for at least 24 hours before serving.
They'll last about two weeks in the refrigerator in an airtight container.
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I hope you enjoyed the recipe! If you did, feel free to rate it and leave a comment!
Recipe
Balsamic Pickled Onions
- Total Time: 10 minutes
- Yield: 10 servings 1x
- Diet: Vegan
Description
TheThese balsamic pickled onions are sweet, tangy, and easy to make in 10 minutes. Add them to bowls, salads, sandwiches, burgers, or toast.
Ingredients
- 1 red onion (400 grams), peeled and thinly sliced
- 2 teaspoons dried oregano (or one sprig of fresh rosemary)
- 1 teaspoon of whole black peppercorns
- ¾ cup (177 ml) water
- ½ cup (118 ml) balsamic vinegar
- ¼ cup (59 ml) distilled white vinegar or apple cider vinegar
- 2 tablespoons cane sugar or maple syrup
- 1 teaspoon sea salt
Instructions
- Add the sliced onion, oregano or rosemary, and peppercorns to a clean, nonreactive, heat-safe container. A large, wide-mouth glass jar works well.
- Combine the water, balsamic vinegar, white vinegar, sugar, and salt in a small saucepan. Bring to a gentle boil over medium-high heat, stirring until the sugar and salt dissolve. The sugar and salt will probably already be dissolved by the time the liquid comes to a boil. Remove from the heat promptly to prevent too much liquid from evaporating.
- Then carefully pour the hot brine over the onions. Let them soften for a few minutes, then gently press the slices below the liquid.
- Cool to room temperature, cover, and refrigerate. The onions are ready once cooled, but they become softer and absorb more brine flavor after 24 hours.
Notes
For a 400-gram red onion, we use a 32-ounce (950 mL) jar.
If there is still not enough brine after letting the onion slices soften in the hot brine, top it off with more balsamic vinegar.
- Prep Time: 5 minutes
- Cook Time: 5 minutes
- Category: condiment
- Method: stovetop
- Cuisine: american
Janet says
They came out great, thank you for the recipe! I've been using them for grain bowls this week.
Allie says
I'm glad you enjoyed the recipe and thank you for leaving a comment.