How Do You Know When Your Ferment Has Gone Bad? (AKA Fermenting is Really Easy, I Swear!)

One of my favorite things about fermenting food isn't the health benefits or the idea of using it as food storage, though those things are great, but I really love how it easy it is.

If you look at vegetable fermentation, at it's core you just essentially put some vegetables in some salty water. Sure, sometimes you can get more complicated that - maybe you want to chop everything, maybe you're fermenting salsa, maybe you're making something alcoholic - but at it's core, fermenting is fairly simple and straightforward.

My biggest concern when I started fermenting foods was that it would go bad. I'm the type of person who throws out the whole container when it gets moldy rather than carefully clean it and disinfect it for future use so trust me when I tell you I hate mold and bad bacteria.

As an American, I was raised to think all bacteria is bad. Obviously, we've been learning in the last few years why that attitude is not only incorrect but can be very dangerous. Some bacteria is good. We need bacteria to live, to thrive. If you're having a little freak out right now because you don't know if you can eat living bacteria, I'd just like to point out that if you eat yogurt, saurkraut, cheese, olives or drink beer, wine or kombucha, then you already consume fermented foods. Congrats!

Now let's move on to what happens if you follow a fermentation recipe. If you look at my fermented jalapeno pepper recipe, you'll find that it's very simple. Peppers. Salt. Water. You get the basic steps. But what's happening in there? What if something goes wrong? What if you accidentally eat the bad bacteria and get really sick?!

Don't worry. I don't want you to die from using my recipe either. 

Here's what's going to happen. On the peppers you bought (and on everything, really) are thousands, maybe millions of bacteria and yeast waiting for their chance to thrive. After you clean the peppers with hot water and toss them in the brine, the salt in the water suppresses the "bad" bacteria and allows the "good" bacteria to do it's thing.

If all goes according to plan, after a few days you'll start to see bubbles at the top of the brine. That's good. It's working. Sometimes you get a lot of bubbles. Sometimes you only get a few. It doesn't really matter.

Then your bubbly ferment will start to turn cloudy. The colors on the fruit will dim. Don't panic. The cloudiness you're seeing is dead yeast. Did I mention that there's also a lot of yeast along with the bacteria? Anyway, it's all going according to plan.

Let it sit a bit longer. Check your recipe. Sometimes ferments are ready to go after a few days, sometimes after a few months, and the annoying thing is (especially when you start out and you're really concerned about bacteria) that the length of time depends on you and your kitchen.

Basically what happens is this: when you start your ferment, it takes a day or two as the bacteria start to wake up. Then it turns into a party. Then the party starts to wind down and everyone goes home (aka dies).

Ideally you want to stick your ferment in a fridge (or somewhere below 60F) right as the party winds down. When your bubbles start to dwindle, that's a very good indication that you should tighten the lid and move your container to a cooler place.

Warmer environments speed things up. So if you live somewhere without air conditioning and it's 95F, then you need to check on your ferment quite a bit because you could have something ready in a few days. If you live in a much cooler place and it's only 75F, then it'll take a bit longer.

If you're ever unsure, which could happen because maybe you didn't get that many bubbles or the temperature fluctuated, I recommend taking a deep breath to brace yourself, then smell it, and taste it. The deep breath is to help calm your nerves - even though I usually know what I'm making and eating, it's still scary to taste-test something! But really, smell it. Does it smell like food? Or does it smell off? Taste it. You'll know immediately if it's bad. (It's probably not bad.)

Here's how you know when a ferment has gone bad (and pay attention, this is important):

1. It has mold. Mold is fuzzy. Mold is usually green. Mold is on the surface. If you have something slimy on the bottom of your ferment? Something white on the sides? Not mold, probably yeast and normal, so go ahead and eat it.

See the fuzzy cloudiness? Normal.

Some cultures feel that mold is normal and okay and they happily scrape the mold off and let it continue. Some others will scrape the mold off the top once and hope it doesn't come back. I'm not really there yet. I don't want to chance it at all so it gets tossed.

2. You have kahm yeast. Kahm yeast grows on the surface. It's white and has little bubbles. Technically it's harmless and you can eat it. However, sometimes it doesn't have a good taste to it and you have to toss the whole thing*. The downside is that you have to taste your ferment to know if yours is fine or not.

That's it. That's really all that can go wrong.

But what about botulism?
Botulism is a common fear for people who can their food, and for good reason. It has serious side effects, including paralysis. In case you're not aware, it's caused by the bacteria clostridium botulinum, and sometimes a few other strains. Obviously, this is a bacteria you want to avoid.

C. botulinum is, like other bacteria, everywhere and is just waiting for the right conditions to grow and thrive. The right conditions: an anaerobic environment that's not too acidic, not too salty, and not too crowded with other bacteria. All of these conditions are the exact opposite of what you're trying to achieve when you're fermenting, and assuming you follow the recipe, to add vegetables in brine, you're going to be fine.

The only time botulism has been linked to fermentation is when you're fermenting fish and meat, and for some reason, they're all reported from Alaska.

So yeah, fermenting can be really easy and you'll know right away if it's safe to eat.

Now get to it!

*I have recently discovered a "cure" for kahm yeast. I'm currently testing it out to see if it works so stay tuned!