Vibrant tangy keto pickled red onions are the bright, crunchy, sweet-and-sour condiment that makes tacos, burgers, and salads come alive. Red onions, garlic, and oregano swim in a warm apple cider and red wine vinegar brine, ready in about 15 minutes. They are gorgeous pink, keep for a month, and add just 1.3 g net carbs per quarter-cup.
If there’s one condiment that can instantly elevate any dish from ordinary to extraordinary, it’s these vibrant, tangy pickled red onions. They’re my secret weapon for adding a bright, crunchy, and perfectly balanced sweet-and-sour kick to literally everything. From jazzing up my morning avocado toast to being the star topping on tacos and burgers, a jar of these beauties in the fridge means a flavor explosion is always just seconds away. Trust me, once you make them, you’ll wonder how you ever lived without them.
Ingredients
• 1 cup / 240 ml apple cider vinegar
• 1 cup / 240 ml red wine vinegar
• 2 tablespoons / 30 g (1.06 oz) granular erythritol, or more to taste
• 1 teaspoon / 6 g (0.21 oz) sea salt
• 2 medium red onions, thinly sliced
• 6 cloves garlic, halved
• 1 teaspoon (5 ml / 0.2 fl oz) dried oregano leaves
• 1 pinch red pepper flakes
Instructions
1. Directions
2. In a saucepan over medium heat, bring the apple cider vinegar, red wine vinegar, erythritol, and salt to a light boil, stirring until the erythritol and salt have dissolved.
3. Place the sliced onions, halved garlic, oregano, and red pepper flakes into a 32-ounce / 1-liter mason jar. Carefully pour the hot vinegar mixture over the top, ensuring everything is fully submerged.
4. Allow the jar to cool on the counter for at least 1 hour. Once completely cool, secure the lid and transfer to the refrigerator. While they can be enjoyed the next day, their flavor deepens and improves after a few days.
5. Store in an airtight container in the refrigerator for up to one month.
Nutritional Information
• MAKES: 4 cups (960 ml)
• SERVING SIZE: ¼ cup
• CALORIES: 10
• FAT: 0g
• PROTEIN: 0.2g
• TOTAL CARBS: 1.5g (0.05 oz)
• FIBER: 0.2g
• NET CARBS: 1.3g (0.05 oz)
Pro Tips
• For a crunchier onion, slice them slightly thicker. For a softer texture that melds into dishes, slice them paper-thin using a mandoline.
• Experiment with different spices like whole peppercorns, bay leaves, or mustard seeds for a unique flavor profile.
• Don’t discard the leftover pink brine! Use it as a base for vinaigrettes or to add a tangy kick to marinades.
• If you’re not following a keto diet, you can substitute the erythritol with an equal amount of granulated sugar or a tablespoon of maple syrup.
FAQ
Q: How long do these pickled red onions last
A: When stored properly in an airtight container in the refrigerator, these pickled red onions will stay fresh and delicious for up to one month.
Q: Can I use a different sweetener instead of erythritol
A: Yes, if you are not following a keto diet, you can easily substitute the erythritol. Use an equal amount of granulated sugar or one tablespoon of maple syrup to achieve a similar sweet and tangy balance.
Q: How soon can I eat the pickled onions
A: You can enjoy them after they have cooled and been refrigerated for a day. However, for the best and most developed flavor, we recommend waiting at least 2-3 days before eating them.
Q: What can I do with the leftover pink brine
A: Don’t throw away the flavorful brine! It makes an excellent base for a tangy vinaigrette salad dressing or can be used as a zesty kick in marinades for chicken or pork.
Pro Tips
- Slice the onions slightly thicker for a crunchier pickle, or paper-thin on a mandoline if you want them to melt softly into dishes.
- Pour the hot vinegar mixture over the onions while it is still at a light boil — the heat takes the raw bite out of the onion without turning it mushy.
- Make sure everything is fully submerged in the brine; pieces that float above the liquid pickle unevenly and can soften oddly.
- Let the jar cool on the counter for a full hour before lidding and refrigerating. They are edible the next day, but the flavor deepens noticeably after a few days.
- Save the leftover pink brine — it makes an excellent base for vinaigrettes or a tangy kick in marinades.
Frequently Asked Questions
How long do pickled red onions keep?
Store them in an airtight container in the refrigerator for up to one month. They are ready to eat the next day, though the flavor improves over the first few days.
Are these pickled onions keto?
Per ¼ cup serving they have 1.5 g total carbs with 0.2 g fiber, about 1.3 g net carbs. The brine is sweetened with granular erythritol, not sugar.
Can I change up the spices?
Yes — whole peppercorns, bay leaves, or mustard seeds all work well in the brine. Keep the vinegar base and the submersion step the same.
Do I have to cook the brine?
Yes. Bringing the vinegars, erythritol, and salt to a light boil dissolves the sweetener and salt fully and lets the hot brine take the raw bite out of the onions.
Recipe card below.
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Vibrant Tangy Keto Pickled Red Onions
Ingredients
Method
- Directions
- In a saucepan over medium heat, bring the apple cider vinegar, red wine vinegar, erythritol, and salt to a light boil, stirring until the erythritol and salt have dissolved.
- Place the sliced onions, halved garlic, oregano, and red pepper flakes into a 32-ounce / 1-liter mason jar. Carefully pour the hot vinegar mixture over the top, ensuring everything is fully submerged.
- Allow the jar to cool on the counter for at least 1 hour.
- Once completely cool, secure the lid and transfer to the refrigerator.
- While they can be enjoyed the next day, their flavor deepens and improves after a few days.
- Store in an airtight container in the refrigerator for up to one month.
- Don't discard the leftover pink brine! Use it as a base for vinaigrettes or to add a tangy kick to marinades.
