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Cultured Guru is an Educational Health & Wellness Brand and a Fermentation Company.

Created and Operated by Microbiologist Kaitlynn Fenley and Photographer Jon Scott Chachere II.

Fermented Foods | Better than Pickled Red Onions

Fermented Foods | Better than Pickled Red Onions

I LOVE fresh and pickled red onions... a lot. We always have red onions in our house and we never, ever run out. We put them in quinoa bowls, in burrito bowls, on avocado toast, and pretty much any savory meal. Want to know what we love more than pickled red onions though? Fermented Red Onions! It's the same great taste of pickled red onions, but with an awesome benefits fermented foods provide: gut health!

Pickled Red Onions are Good, BUT Red Onions as a Fermented Food are Even Better!

We fermented some for two weeks and some for four weeks, and they are delicious! I prefer the four week fermented batch because they are just a bit more tart. Four weeks allows for the Lactobacillus in stage three of the fermentation to make more lactic acid, dropping the pH a bit more, and allowing the flavor to develop. 

If you are curious what the elusive probiotic Lactobacillus look like, here is a picture from my microscope:



This is just one drop of brine so you can see, it's rich in probiotic Lactobacillus.

Fermented Foods | Better than Pickled Red Onions
Fermented Foods | Better than Pickled Red Onions
Fermented Foods | Better than Pickled Red Onions

Mastering Fermented Foods

If you're going to master fermentation you'll need to use weight measurements for your fermentation ingredients. That means you need a kitchen scale. In order to select for the best probiotic bacteria (the ones that are actually beneficial) in your ferments, you must weigh salt to create a specific salt concentration. Weighing salt is the only way to create a salt concentration that will select for only probiotic microbes to thrive. You can read more about why you must weigh your salt here.

This is the scale we use in our home kitchen to weigh salt.  

We Recommend either one of these scales:


Supplies You Need to Make Better Than Pickled Red Onions:

Fermented Foods Better than Pickled Red Onions

Better Than Pickled Red Onions




  1. Wash your fermentation equipment (jar, weight and lid)
  2. Peel then wash your red onions in cool water. Using a knife, slice your onion to desired thickness.
  3. Place your kitchen scale on the counter. Turn it on and set it to weigh in grams.
  4. Place a mixing bowl on your kitchen scale and tare/zero the scale. Note: Taring/zeroing the scale with a container on it subtracts the weight of the container, allowing you to weigh only what is added to the container. After taring/zeroing the scale, the scale should read 0.0 with the container on it.
  5. Add chopped onion into the bowl on your scale until the scale reads 200 grams.
  6. Remove the bowl from your scale and set aside. Place your empty, clean mason jar on the scale, and tare/zero the scale. Make sure your scale is still set to grams and add 200 grams of Cultured Guru Sauerkraut Brine and 100 grams of apple cider vinegar to the jar.  
  7. Add the 200 grams of onions from your bowl, into the mason jar.
  8. Place a small bowl on your scale and tare/zero the scale. weigh out 5 grams of salt. Then add the 5 grams of salt to the jar of onions.
  9. Place your standard mason jar lid on the jar, and secure. shake the jar vigorously for 2 minutes.
  10. Remove the silver standard mason jar lid. Place your fermentation weight in the jar making sure to submerge the onion pieces and weight fully in the liquid.
  11. Secure the standard mason jar lid, or your airlock lid to the mason jar.

How to Care for Your Fermented Foods 

Better than Pickled Red Onions Tips

This is a different kind of vegetable fermentation: You are culturing the onions using sauerkraut brine, so you only need to ferment them for 48 hours, then place them in the fridge.

Always Trust your sense of smell: Fermented onions should smell pleasantly sour and a bit oniony. Never eat anything that smells repulsive. 

Never eat anything that had mold growing on it: By following directions you should not encounter this problem. 

Taste test at 48 hours: If you prefer the onion to be more tart and sour, let them ferment 12 more hours.

What Temperature Should I Keep My Fermented Foods At?

Keep your fermenting red onions at a temperature between 70-80 degrees F. Keep out of direct sunlight

How Long Should I Ferment My Better than Pickled Red Onions 

Since this is a fermentation with added cultures from the sauerkraut brine, you only need to ferment the onions for 48 hours.

Do I Need to Refrigerate My Better than Pickled Red Onions

After fermenting place a regular mason jar lid on the jar and refrigerate. Consume within 6 months for full probiotic benefits!

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