Fermented Onions for Tricky Cultures

Fermented Onions for Tricky Cultures

Hey foodie friends,

Sorry I have been absent. My littlest has required much attention of late. We have had the winter of winters in terms of illness here and she is my one who is prone to pneumonia whenever anything as silly as a cold moves through the house. She is appalled by most things fermented, save hummus, so it is difficult to keep her already delicate immune system strong.

This has been life of late… She’s cute even with a mask.

I have still been playing in the kitchen but have been somewhat absent from social media and blogging. First things first, right?

This is essentially a re-post. I had a friend pull a recipe from my blog to make fermented carrots recently and he asked about the “fermenting brine” I had mentioned in order to help along a persnickety culture. A lot of people use whey, and I have done so as well, but whey is highly inflammatory. My preference is to keep ferments pure if I can. Vegetables are vegetables and those who cannot tolerate dairy should not fear that it may be in their hummus or their carrots.

I had a post on making cultured red onions, which boasted all the lovely gut health info so have a read if you like. This post is the same recipe but I did a batch of red onions for eating and a batch of white onions for the purpose of having clear fermenting liquid “juice” on hand for other ferments. We still eat the white onions but they tend to go into things that the lovely purple will make unappealing.



  1. Lay all your tools on a cookie sheet with a silicone baking mat
  2. in the oven and heat to 180 degrees Fahrenheit to sanitize everything.
  3. Peel, wash and slice your red onions into thin strips, or use a mandolin.  For speed (which is completely necessary when you have 3 or more children running around) I used the latter method.
  4. Pile the onions into the sanitized 2 Liter jar.
  5. Smash down with a washed French rolling pin or wooden spoon to release juices and be sure you have a couple inches space at the top.
  6. Cover with non-chlorinated water and your salt of choice.
  7. Weigh down with a sanitized fermentation weight or small jar.
  8. Wait 2-3 Days and as long as a month for the healthy bacteria to grow.

Use the liquid from these to help along another batch of cultured veg, or to ferment your hummus or other dips. 

There you go… if you’re struggling with unruly wild yeasts in your home and you need a cultured win from which to borrow, here you are. 🙂

Cultured Onions

Prep Time 30 mins
4 d


  • 1-6 onions red, white or yellow
  • 1 tbsp pink salt per quart
  • non-chlorinated water


  • Sanitize jar(s) and lid(s) in the oven at 180 F for 5 minutes
  • Reserve the outside peel of the onion and then thinly slice the rest either in a food processor or with a good knife.
  • Fill your jar with onions (alternatively, you can slice up one onion in the jar if you are mostly using this for brine to activate other cultures like hummus)
  • Pour pink salt over the top: 1 Tbsp per quart of onions + liquid (so for a 4 quart jar use 4 Tbsp)
  • Weigh the onions down with a sanitized fermenting weight or the outside peel of the onion.
  • Pour a bit of extra virgin olive oil or avocado oil around the outside of the weight to create a coat above the liquid, thereby keeping out the bad bacteria and allowing the gasses to escape.
  • Seal the jar and wait! 4-7 days is expected for it to fully culture. When the bubbles stop, they are done.


5 thoughts on “Fermented Onions for Tricky Cultures”

Leave a Reply

Your email address will not be published.

Recipe Rating