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fermented red onions topping a salad

Fermented Red Onions

Fermented red onions are slightly sweet, tangy, vibrant and endlessly versatile. Make this gut-healthy condiment today!
Print Recipe
Prep Time:10 minutes
Fermentation Time:7 days
Total Time:7 days 10 minutes

Equipment

  • Mixing bowl
  • 1 quart jar
  • fermentation weight
  • fermentation lid
  • measuring spoon
  • knife or mandolin

Ingredients

  • 2-3 red onions, thinly sliced
  • 2 cups filtered water
  • 1 tbsp salt (avoid iodized salt as it can hinder fermentation)
  • Optional seasonings: peppercorns, garlic cloves, bay leaves, pinch of red pepper flakes for a hint of heat

Instructions

  • In a bowl, dissolve the sea salt in filtered water. This saltwater brine will create an ideal environment for fermentation by preventing harmful bacteria from developing.
  • Peel and thinly slice the red onions. Thin slices help the onions ferment more quickly and make it easier to use as a topping or garnish.
  • Place the sliced onions in a clean glass jar, packing them down as tightly as possible. Leave a bit of space at the top to allow for expansion during fermentation. Add any optional seasonings, like peppercorns, garlic, or bay leaves, for added flavor.
  • Pour the saltwater brine over the onions until they are fully submerged. It’s essential to keep the onions below the brine to prevent mold from forming. You can use a small fermentation weight or a clean, heavy object to keep the onions submerged.
  • Loosely cover the jar with a lid or use a fermentation lid to allow gas to escape. Leave the jar at room temperature (around 65-75°F) out of direct sunlight.
  • Let the onions ferment for about 3-7 days, depending on your taste preference. Check daily, ensuring the onions remain submerged. After a few days, taste them to see if they’ve reached your desired level of tanginess. They should have a slightly sour, pickled flavor with a hint of sweetness from the onions.
  • Once the onions have reached your preferred flavor, seal the jar with a tight lid and transfer it to the refrigerator. The cold will slow the fermentation process, and the onions will keep for several months.

Notes

*Calories are approximate
Course: Appetizer, Salad, Snack
Cuisine: American
Keyword: condiment, fermentation, fermented onions, pickled onions
Servings: 1 quart jar
Calories: 13kcal
Author: dani
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