Summer in a Bottle – Fermented Chilli Sauce



I’ve had a fabulous crop of chillies so far and this season I really wanted to experiment with fermenting for flavour.

The Habanero chillies in particular have been really prolific this year and while not as hot as past seasons, incredibly flavourful, with a citrus tang that I thought would make a great sauce.

So, here’s the recipe I developed for the ferment and the subsequent sauce. I’ve tried to include as much detail as possible about my process, but as always, please ask if there’s something I’ve missed that needs clarification!

Fermented Hot Sauce 



Fresh chillies (I used ripe Habaneros from my garden)

Salt (cooking or kosher salt without additives is best)

Water (filtered or rain water boiled and allowed to cool to room temperature)

(For the sauce) Lemons, vinegar or citric acid (available in most supermarkets as a powder in the baking needs section).

You’ll also need gloves (if the chillies are Habaneros or hotter this is necessary!), some reasonably accurate kitchen scales and measuring spoons, a scrupulously clean jar, a weight to hold the chillies down and a lid that can accommodate an airlock or similar. Even with small ferments, I prefer to exclude any organisms other than what’s on my fruit or vegetables. I’d also recommend a book of litmus paper (available from most chemists) to check pH levels of the final product, especially if you’re not planning to put the sauce through a water bath.

Ferment Method:

Before starting, clean everything – otherwise your ferment can pick up organisms you might not want! Sterilise jars, lids, weights, measuring spoons and anything metal in boiling water, thoroughly clean chopping boards, knives, bowls and gloves in hot soapy water and rinse thoroughly.

Wash the chillies and dry them carefully. With gloves on (if you’re using hot chillies) remove the stalk and chop the chillies. I like the heat, so I left the seeds and membrane in, but if you’re looking for a more mellow and somewhat smoother sauce, cut the chillies in quarters and scrape out the seeds and inner membrane with a paring knife.

Weigh the chillies and pack them tightly into the clean jar. You can either sprinkle the salt over the chillies (which I did) and pour the cooled water over them or mix the salt until it’s fairly well dissolved in a small amount of water. I went for a roughly 8% solution and had 200 g (7 oz) of chopped chillies. This meant needed 16 g salt, which is a scant tablespoon. (My old spring loaded kitchen scales aren’t designed for very small amounts but digital scales are perfect for this job).


Once you’ve added the brine, it’s important to twist the jar a few times or push the chilli pieces around with a clean skewer to remove as many air bubbles as possible and weigh the chillies down so they are entirely submerged. I use wide mouth Mason jars with easy to clean glass weights and a silicone Pickle Pipe – a waterless airlock that allow ferments to release carbon dioxide, without allowing air (and unwanted organisms) in. Then cover, label and leave in a dark, cool place for about a week.

I keep my ferments in pantry shelves that I walk past all the time, so I tend to check them once a day. It never ceases to delight me, seeing bubbles, smelling the wonderful aromas and particularly with this ferment, seeing the colour really develop. It’s also a good habit to check your ferments to make sure nothing has risen above the level of the brine and no unwanted moulds have developed.


Fermenting Habanero Chillies, weighed down with a glass insert and covered with a Pickle Pipe.

After a week to ten days, check your chillies (I left mine for a week). They should still be submerged and reasonably crisp, and the brine should smell good and taste spicy and salty. It’s quite normal for a thin film to form across the top of the brine and I recommend removing this carefully with a spoon. If any chillies aren’t submerged and showing signs of mould, I would recommend removing the uncovered ones carefully from the brine (toothpicks are good) and composting them. The rest of the ferment should be fine. Of course, if you’re assailed with funky smells and your chillies are slimy, don’t take any risks – throw the whole lot in the compost bin – food poisoning is not to be trifled with!

If you’re happy with the ferment, here’s the rest of the recipe:

Sauce Method: 

Once again, assemble all your tools first and make sure they’re ridiculously clean – preferably hot water or heat sterilised. You’ll need a non-reactive sieve and bowl, a food processor or blender, a small funnel, bottles and caps and (if you opt for lemons) a grater and hand juicer or citrus press.

Remove the weight from your ferment and sieve the brine off the chillies into a bowl. If like me, you’re chilli-obsessed, reserve the brine (it’s deliciously spicy!) put it in a clean bottle, cover and refrigerate. It will keep for a few weeks in the fridge and I use it in curries, stir fries, soups or stews for an extra kicking salt replacement 🙂

Put the chillies into a blender jar or food processor with either vinegar, fresh lemon juice or citric acid powder and pulse to the desired consistency. I also added a tablespoon or two of the brine. The target here is to bring the sauce to around 4.5 pH – quite sharp. I used the juice of 3 lemons and, for extra citrus notes, the grated zest.


Next, carefully put this into the sterilised jars and seal immediately. It’s possible now to put the jars in the refrigerator where they’ll last for months and be full of probiotic goodness, but I’m here for flavour – so I opted to do a water-bath sterilisation for 10 minutes This stabilises the sauce, guaranteeing longer pantry shelf life.

This sauce is sensational with – well, pretty much everything! My original 200 g of chillies made two 125 g bottles plus a few tablespoons that I’ve put in a sterilised jar and refrigerated. It’ll be interesting to see if there’s any significant flavour difference between the water-bath processed sauce and the refrigerated version.


The finished product after water-bath processing – that beautiful colour!!!

I think this basic fermentation would work with any chilli and I’m going to start one with Cayenne chillies and garlic later this week that I plan to finish with my home made Apple Cider Vinegar.

Let me know if you try this recipe, what flavour combinations you use and how it works out – I always love to hear from you 😀

Meanwhile, take care wherever you are on this beautiful planet ❤