Our household is a bit crazy about chilli sauce. We always have a tonne of different sauces in the fridge, and we can’t resist trying a new one. One favourite is a brand from Australia called Bunsters. Their ingredient list is an inspiration, and some of the names are a bit NSFW but fun.

Why ferment chillies?

  • Preservation. Lots of fresh chillies become lots of shrivelled dried chillies pretty quickly.
  • Flavour. Fermenting adds a layer of funky flavour that is totally delicious. It also mellows the sharp, sometimes overpowering heat into a more complex, tangy spice.
  • Health. Many studies talk about the beneficial bacteria introduced when eating naturally fermented foods.

Everyone is doing it!

Tabasco is only three ingredients that are fermented and aged in oak barrels, and the original Huy Fong sriracha chilli sauce is made from chilli peppers, garlic, vinegar, salt and sugar, fermented and blended together.

Locally, we love Yardbird’s Flagrant Hot Sauce, which we tried at the Shake Shack collaboration, and we got to talk to Chef Matt Abergel of Yardbird, who developed the sauce here in Hong Kong.

Flagrant Hot Sauce at the Fiyah Heat Store

Chef Abergel even shared how they make it! Red chillies are fermented dry with koji for a few weeks. They are then blended in a secret recipe that includes yuzu, vinegar and sugar and strained. The popular sauce has taken on a life of its own, popping up at restaurants such as The Last Resort and online at FIYAH! Heat Store.


Fermenting with koji is a bit intimidating for those of us who haven’t used it before, so I ferment using the super-easy lacto-fermentation method (i.e., you submerge stuff in salted water and forget about it). Instead of yuzu, I add orange juice for a touch of citric acidity and sweetness. And I don’t strain it because I like it a bit chunky. Choose your own adventure!

The first time I made this, we had a bag of Vietnamese chillies that were so spicy, we temporarily lost our hearing after eating them. But there was no way I was going to throw those suckers away, so we used them and supplemented with jalapeños, capsicums and coloured baby peppers. You can use any peppers you can find of any colour, but the end product is actually prettier if you stick to chillies and peppers in red.

Lacto-fermented chilli sauce is very simple, but fair warning here: it’s quite stinky whilst it’s bubbling away.

Depending on the heat you like (and the heat you have), you can determine your own proportions. Fermenting chillies tends to mellow their heat, so we went with just six or so tiny “death chillies” (our name, not theirs) and filled the rest of the jar with lesser beasts. They compact down quite a lot after the first couple of days, so don’t be afraid to fill the jar if you can – just ensure you have a weight of some sort on top to keep them submerged. If you don’t have a fancy glass weight, you can use a small, sterilised jar filled with coins.

Lacto-fermented chilli sauce recipe


  • 6–10 bird’s-eye or other spicy chillies
  • 4 jalapeños
  • other large coloured peppers (1 or 2 each of red, yellow or orange)
  • 4 cups water
  • 3 tbsp fine salt
  • 4 cloves peeled garlic
  • 2cm thumb of ginger, sliced
  • black peppercorns, mustard seeds or toasted Sichuan peppercorns
  • 1 tbsp orange juice (optional)


  1. Boil the water and let cool. When it’s still warm, add the salt and stir in. You are looking for a brine of about 2% salt.
  2. Lightly toast (dry-fry in a non-stick pan) the Sichuan peppercorns (if using).
  3. Get some gloves on and cut up all those peppers. Chunky is fine. Do not touch your eyes for the entire day or pay the price!
  4. Layer the ingredients and fill the jar with brine.
  5. Put a sterilised weight on top to ensure the pieces remain under the brine. Some of the peppercorns will get pushed to the top and will probably collect a layer of white film that is harmless (but apparently badly flavoured) Kahm yeast. Every week, I open my jar and scoop out this layer and the peppercorns that have accumulated at the top of the brine.
  6. Store in a cool, dark place. Ferment for roughly two weeks during summer, but up to four weeks during winter.
  7. After fermenting, drain the brine (reserving 1 cup) and rinse the ingredients if you like. Add all the ingredients to a blender with 1 tbsp brine and the optional orange juice. Blend until smooth, adding additional brine or juice if you prefer a runny sauce. You can strain the solids, but I do not, ending up with a chunkier sauce.
  8. Put your chilli sauce on any pasta, rice, noodle or egg dish!

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IT, burger & beer specialist at Foodie. Loving sichuan like a drug, hit me up with that peppery numbness

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