Lacto-Fermented Onions Recipe

These lacto-fermented onions will quickly become your favourite condiment!

Onions are one of the easiest fermentations to achieve. By using just a few ingredients that you probably already have at home, you’ll end up with a condiment that will refine any sandwich or burger.

Why Ferment Onions?

If you like pickled onions, you’ll love lacto-fermented onions!

Lacto-fermentation completely transforms the onions. Their texture softens and they become smoother as if they had been partially cooked.

They also lose some of their spiciness, making them perfect for replacing raw onions in recipes.

As with every lacto-fermentation, fermented onions develop a pleasant acidity, although much less intense than pickled onions. Their flavour deepens and becomes more nuanced.

In addition to taste, fermentation has many benefits. Fermented onions are packed with probiotics and enzymes, and are much easier to digest than raw onions.

As onions sometimes contain sulphur compounds, the smell can at times be surprising! Don’t panic, it’s like blue cheese: you get to like it, and soon start to love it.

How to ferment onions

Which Onions to Choose?

Any onion can be used in this recipe. It depends on your taste, and what you have in your pantry!

Red onions are sweeter and blend well with the acidity of the fermentation. Yellow, white and Spanish onions are also excellent options.

Small onions, such as pearl or Egyptian onions, can also be used.

For best results, choose fresh, firm onions. Beware: this recipe may make you cry twice. The first time, when you peel the onions and the second time when you finish your jar ;)

Lacto-Fermented Onions Recipe

Lacto-Fermented Onions Recipe

Learn how to turn ordinary onions into a delicious condiment! This easy-to-customize recipe will teach you how to ferment any onion.
4.08 of 83 ratings
Course Salad



  • 500 g onions (red, yellow, etc.)
  • 10 g salt
  • 1 tsp. of spices of your choice such as cumin, coriander, black pepper, fenugreek, etc.
  • Water if necessary


  • Peel and cut the onions into chunks. Use facial tissues, ski goggles, an open window, or any of your grandmother's tricks to limit tears.
  • Put the onions in a bowl and add salt and spices.
  • Mix onions and salt thoroughly.
  • Let it stand for 15 minutes.
  • Mix and transfer the onions to the glass jar. Squeeze well as you proceed to remove the air bubbles (a fermentation pestle works very well for this!)
  • Add a glass weight to keep the onions submerged.
  • If the brine does not submerge the onions, pour some water into the jar.
  • Install the airlock lid. Ferment for 10 to 14 days.


This fermented onion recipe can be stored in the fridge for 6 months without any problem.
Have you tried it?Share and tag @revolutionfermentation!


How to Eat Fermented Onions?

Here you go! You have your secret weapon for your next family barbecue.

Add fermented onions anywhere you would put raw or pickled ones:

  • Sandwich
  • Hamburger
  • Tacos
  • Marinade
  • Appetizers
  • Salads

We love adding fermented onion to our sauerkraut or hot sauces for an extra layer of flavour.

But that doesn’t mean we can’t enjoy onions on their own. Believe us, one can finish a jar of lacto-fermented onions in no time at all!

Get Started!

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