Updated: Sep 7, 2021
Lacto-fermentation is such a fun and easy kitchen project. Fermenting vegetables is almost like having a temporary low key pet, it's good to give them a visit and make sure they're comfy and happy, but they basically really easy to care for. I've had a lot of success in the past mixing up fermented sriracha type hot sauces, so I thought my time in self-isolation could benefit from a fermentation project.
So what is fermentation? My favorite description of the practice of fermentation is that it is a "controlled rot." This sounds disgusting but it is accurate! The food we're fermenting is still breaking down, but it's doing so in a way that is much slower and beneficial for human consumption. What we're doing when we're pickling and fermenting food is creating an environment that is hostile to bacteria that cause food to spoil and friendly to bacteria that can preserve the integrity of the food in a really delicious way (and consequently promote good gut health). Lacto-fermentation uses salt to invite the beneficial bacteria, Lactobacillus, to fermentation party, hence the name lacto in the name. The process converts sugars and starches into acids, making the environmental too acidic for dangerous microorganisms to live. This is the same type of fermentation used in the preparation of dill pickles and kimchi. For more reading on this, see the University of California's guidance on food preservation: Preserving the Season: Fermentation.
Many people are scared of fermenting foods because they are worried about getting sick from botulism. The nice thing about fermenting food is that it happens really quickly and there are a lot of indicators of spoilage that sensible adults should be able to recognize. If you're confident in your ability to detect spoiled food - you will be just fine fermenting food at home. I have had my fare share of fermentation failures throughout my experiments, but it has always be obvious to me that I shouldn't eat the food. Things to look out for are 1) slime and 2) unpleasant odor. Now, ferments will always smell sour and funky, and before you start fermenting foods at home you should be very familiar with how fermented food smell. They smell of vinegar and yeast, but beyond that they kind of difficult to describe. So definitely be familiar with the smell lacto-fermented pickles before you try making them. But a spoiled ferment will not smell like something you want to eat, so if it stinks, it's out! Now, back to slime. Check the viscosity of the brine, it should be as watery as it was when you mixed it. If it is more viscous, you're probably in trouble. If you pull out a pickle and it's slimy, it has left the controlled rot place and has gone to the garbage rot place - throw it out! In my opinion, there's no saving a ferment that has gone off, you have to throw out the entire thing, clean your jar and start over. But again, it will be obvious to you that it's bad. If you open the jar and it smells like the delicious sour pickles you're familiar with, then that's exactly what you've got on your hands! Your ferment would never smell and taste delicious while also being spoiled and poisonous. That's just not how rotten food rolls.
Back the the recipe! I thought I'd give my hotsauce a Thai edge so I've used Thai green chilies and cilantro roots as the flavor base. I then worked kind of intuitively to adjust and workout the recipe. I ended up adding some fresh papaya to add body and sweetness (mango would also be a great option!). Since the papaya was ripe, it slightly muddied the color of the hot sauce, so that's something to keep in mind. If I had gone with yellow, orange red peppers I would have a much more vibrant colored hot sauce on my hands -but I'm not really bothered by it, it's still a pretty green sauce. This is quite a spicy sauce on it's own, but once it's added to food, it's totally delicious and a completely tolerable spice level if you can handle some spice.
Fermented hot sauces are so easy to riff on, so it's totally worth a try! Once you ferment your peppers you can build the sauce in any way you'd like. You can season with fish sauce, soy sauce, honey, mustard, mint (oh mint! I like that idea!!) the possibilities are literally endless!
Below you'll find the recipe for the hot sauce, and further below that is the recipe for the fermented chilies.
Recipe: Fermented Green Chili Papaya Hot Sauce
Yield: about 3 cups
Hot Sauce Ingredients:
1/3 cup fermented green bird's eye chilis
1/2 cup fermented bird's eye chili brine
3 fermented coriander roots (optional)
2 T palm sugar (or any sweetener)
1 cup fresh papaya
1.5 cup fresh sweet green or yellow sweet pepper (bell pepper or any sweet pepper)
1/2 bunch cilantro
Juice of 2 limes
1 T garlic
Add all the ingredients to your blender and blend until smooth. When you've got it smooth, stick a spoon in there and stir it around to check the consistency. At this time, you should also give it a taste for seasoning. If you'd like it thicker and sweeter you can add more papaya or sweet pepper. If you'd like it thinner, add some water or lime juice if it needs more acid. Store in a glass bottle in the refrigerator for... a very long time. Because this is a live product, it will last for many months. As long as it smells good, it's still edible.
How To Lacto-ferment Thai Chili Peppers
The tricky bit with lacto-fermentation is the salt to water ratio. I have had trouble with online recipes because they always call for table salt and I never buy table salt. So for any lacto-fermentation project I embark on, I will always use the salt:water ratio from Olia Hercules' book Mamushka which is 1 liter of water to 3 tablespoons of sea salt. The salt I use is kosher sea salt, so it's a coarse salt but not an exaggeratedly chunky salt. The mill of the salt is important because one tablespoon of table salt is a lot more salt by weight than kosher sea salt. So you can either under salt or over salt the bring if you're not using the right salt for the recipe. If you under salt you will get some yeast bloom that will cloud up your brine and your ferment could spoil. If you over salt... well you'll have a really salty unpleasant end product - it won't spoil but, it won't taste good.
Lacto-Fermented Thai Chili Peppers Recipe
1/2 cup fresh bird's eye chilis (green)
3+ coriander roots (optional)
1/3 L water (33 ml)
1 tablespoon kosher sea salt
A small-medium sized glass container, lid and small weight. **I used a drinking glass and a little ceramic dish shown in picture above
Clean and trim your vegetables; remove the tops from your chilies and clean the coriander roots of the sand that might be stuck between the stems.
Fill your container with the water and salt and stir well to dissolve all the salt. Plop your vegetables into the container. You want the vegetables to stay below the brine at all times because any vegetable exposed to air with mold and will likely then turn your entire ferment to a slimy spoiled mess. So you need something to weigh down the veggies below the water - thus the little dipping sauce bowl I've used before. You need to use something that is acid safe (no plastic imo! glass, ceramic or stainless steel are the options). You also want a lid, to keep spores and dust and things from falling into the ferment. So my little bowl is ticking two boxes, it's keeping the vegetables submerged under the brine and it's covering the entire opening of the glass. You don't want a tight seal on the container because the ferment will produce gas, so that needs to be released from the jar. I always have a plate or tray under my ferments to catch any liquid that might escape from the jar due to the activity happening in there. Sometimes you'll get lots of bubbling which can cause the brine to leak out. If you don't see bubbles, that's ok. I didn't see any with this recipe.
Once you've got your ferment all set up, all you need to do is let it sit and do its thing for 3-5+ days. Put it in a place where it's out of the way and won't be knocked over, but not so out of the way that you forget about it. Check on it once a day, just to make sure that none of the vegetables have moved around and risen above the brine. You might see some evaporation, so you can top off the water a bit if that's needed to keep everyone away from that air. The color will go from bright green to a dull green once it's ready, but it's up to you to decide how far to take the ferment. Open the jar and give it a sniff every day once you see that color shift, and you will smell it getting more and more sour. When it's sour enough, refrigerating it will slow (nearly stop) the fermentation. Store in a glass container (with a top) in the fridge for many months.