Horizontal shot of fermented guava hot sauce.

The Best Fermented Guava Hot Sauce

I started getting into fermentation a couple years ago. Kombucha came first. I was obsessed with the stuff, but buying $4 bottles of it daily seemed like an unwise financial decision. Next came sauerkraut and kimchi, followed by random vegetables, sourdough, and more recently, nut cheeses and hot sauces. Fermentation can be scary and weird. It can also be dangerous if done irresponsibly. But done safely, this ancient food preservation technique can yield complex and delicious flavors that help boost gut health. In this post, I’ll teach you how to make a simple fermented hot sauce. Fermenting hot sauce is incredibly easy, and has a lower risk of slime and mold than other ferments I’ve done, so it seemed like a good one to start you with. It’s also insanely delicious. Seriously – I want to put this fermented guava hot sauce on everything.

Fermentation Basics

Before I get into the recipe, I should probably give you some background on fermentation. Fermentation (specifically lacto-fermentation) is the use of beneficial bacterias to preserve food. Basically, you’re extending the longevity of your food by creating an environment for healthy bacterias to thrive. You need very few tools and ingredients. Fermenting sauerkraut, for instance, only requires shredded cabbage, salt, and a jar! The salt kills the bad bacteria, allowing the remaining good bacteria to transform the food’s natural sugars into lactic acid. This creates an acidic environment, which helps to preserve the food over time – and also creates unique flavors. This is the process by which everything from kimchi to vinegar to beer is created.

I can’t delve too much deeper into the science of fermentation, because to be perfectly honest that’s about all I understand, but I will say that the process results in some truly interesting tastes and textures. It’s also super fun (and highly encouraged) to taste and smell your fermenting goods at different stages of the process. Doing so will help you understand how the flavors develop and figure out when they’re ready! There’s no set amount of time for which you should let things ferment – only guidelines. You’ll be the one eating them, so feel free to finish them off once you’re happy with the taste.

Safety and Sanitation

Since you’re literally breeding bacteria here, you want to make sure that you’re doing it safely so you don’t make yourself and others sick. The most important thing you’ll want to do is clean everything thoroughly before getting started. There are a couple of ways you can do this. The safest is with boiling water. Alternately, you can clean things with dish soap so long as it’s not antibacterial. Remember, we want bacteria.

As I mentioned earlier, you can ferment using minimal tools, but there are a couple that I find really helpful for keeping mold at bay. I love these air lock fermentation lids, as they reduce the risk of mold while also alleviating the pent up gas and pressure that builds during the process. Fermentation weights are also incredibly helpful, though you won’t need them for this hot sauce recipe if you follow my technique (more on that in a bit).

If you opt not to use an air lock lid, you have a couple of options. Cheesecloth over the mouth of your jar, bound by a rubber band, should do the trick. You can also just screw the jar’s lid on, but be aware that carbonation will build as your sauce ferments, so you’ll need to “burp” your jar daily. In English, that means you’ll need to briefly remove and replace the lid every day so your jars don’t build up too much pressure and explode.

Apart from that, just be on the lookout for mold! Basically, if you see anything black and fuzzy start to grow in your jar, it’s best to toss it and start over. Better safe than sorry. I know this may sound scary, but trust me – it’s very easy to avoid any of these pitfalls. We’ve personally never exploded any jars, and we’ve really only had mold pop up a couple of times toward the beginning of our fermentation journey. I did once let a kombucha go too long, resulting in a bunch of mold and such a horrific stench that I legitimately vomited while trying to clean out the container. But that was 100% my fault. Toss moldy ferments when you need to, and I guarantee this won’t happen to you.

Fermented Hot Sauce Process

There are a couple different techniques you can use to ferment hot sauce. Some people ferment the fresh peppers (plus any additional ingredients) whole, then throw them in the blender once they’re good and ready. I prefer to blend my ingredients prior to fermenting. I find that it gives me a better idea of how the flavors are developing on a day-to-day basis.

If you do decide to ferment your ingredients before blending, you’ll need to make a brine. A brine can be as simple as water and salt, though you can add spices if you’d like. It’s the water to salt ratio that’s important when using a brine. I’ve seen 1 quart of water to 3 tablespoons of sea salt used quite a bit in pepper brines, but this’ll obviously depend on pepper quantity. If you’re fermenting veggies in a brine, just know you’ll need to keep your ingredients under the liquid. This is integral for keeping your ferment mold-free. It’s also where the fermentation weights that I mentioned earlier come in. You don’t have to buy weights, though. Some people use rocks or found objects as weights. I prefer the glass weights that I linked to, though, because they’re perfectly sized and I enjoy having one less thing to think about.

Whether you’ve fermented your ingredients before blending, or fermented the pepper mixture after the fact, at the end of your ferment you can choose whether to strain the liquids out to create a thin Tabasco-like texture, or leave it a bit thicker for more of a salsa situation. I prefer the latter, but you do you. Either way, you can finish your hot sauce off with a bit of vinegar before putting it in the fridge, where it’ll last almost indefinitely.

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Now, without further ado, let’s jump into the recipe!     Fermented Guava Hot Sauce

A container of fermented guava hot sauce.

Fermented Guava Hot Sauce


  • 8 oz jalapeños
  • 8 oz sweet banana peppers
  • 4 cloves garlic
  • 2 guavas
  • 1 tbsp sea salt
  • 2 tbsp apple cider vinegar


  1. De-stem the peppers. Then place them in the blender. If you don’t have a high powered blender, you might want to chop them up a bit before blending. Add the garlic and salt to the blender as well. Scoop the seedy centers out of your guavas, and then add them to the blender. Blend until all the ingredients are combined and smooth.
  2. Transfer the puree to a jar and top it with either an air lock, a cheesecloth or a regular old jar lid. Now put it somewhere cool and dark and leave it there for a few weeks. I let mine go for 3 weeks, and I’d say that was pretty perfect. But anywhere between 2 and 4 is probably good. Smell and taste your fermenting hot sauce regularly in order to decide when it’s ready! (Hint: it’s ready whenever you’re happy with it.) Check on your ferment daily if you can. You’ll start to see it bubble. Mine bubbled like crazy due to all the sugar in the guava and peppers. Bubbles are a good sign – they mean that it’s working! Be sure to burp your jar daily if you’re using a regular lid. You’ll also want to gently stir or push the puree down if it starts to develop air pockets so as to avoid mold. I had to do this once a day for the first week because of how active it was.
  3. Once you’re happy with the flavor of your hot sauce, mix in 2 tbsp of apple cider vinegar before topping with a regular jar lid and transferring to the fridge.

Now a quick question! Did you enjoy this post? Could you see yourself giving fermentation a try? If so, I’ve got loads of other posts up my sleeve. I’ve experimented with fermentation quite a bit, and with the exception of bananas (which were fucking disgusting), everything turned out great. That said, I totally get it if you don’t have the patience or desire to ferment things. So let me know in the comments whether you’d like to see more content like this in the future, along with any specific ferments you might be interested in!

4 thoughts on “The Best Fermented Guava Hot Sauce”

  1. Totally here for more fermented recipes! This is not something we would normally do (Hampton is not a fan of much heat), but I am trying to do more with peppers and I think this could become a fave.

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