Can Black Olives Go Bad? Here’s What You Should Know

These black pearls of the Mediterranean are more famous for their oil than themselves. But still, whether you put them on your pizza, eat them at breakfast or simply have them with bread, black olives are loved and eaten all around the world.

They’re also one of those few foods that are delicious and have tons of health benefits at the same time. They’re packed full of healthy fats like oleic acid, which drastically lessens any risk of heart disease and inflammation in the body. They are full of antioxidants like vitamin E, oleuropein, hydroxytyrosol, tyrosol, and minerals like calcium, potassium, and magnesium.

You should be careful about the olives you use in your dishes though; they can cause just as much harm than good if they’ve gone off. To help you avoid that, today I’ll show you how to tell if black olives have gone bad. I’ll also let you know how to properly store them to prolong their shelf life.

How Long Do Black Olives Last?

Typically, black olives last a long time in the refrigerator because, more often than not, they are cured with salt or brine. If you haven’t opened your can of olives yet, you can always rely on the expiration date on the can, in fact, they will usually be safe to eat even a few months past their date. So, they should be good for a year or two if they are in a salty brine, and not opened.

After you open your can of olives, you should finish them ideally within a week or so. Of course, it depends on the curing processes of the brand; some brands may advise you to consume their product within 3 days, while others can say 3 weeks. A good rule of thumb is that a saltier and/or stronger brine means more shelf life as long as you keep them submerged.

What Difference Does Brine Make?

It makes all the difference! When black olives are submerged in a salty brine, a process called lacto-fermentation kicks in. This protects them against certain types of bacteria that cause them to spoil and, if we eat them, make us sick. Luckily, these harmful bacteria cannot survive in a heavily salted brine solution too long. Thus, black olives submerged in a salty brine solution will last much longer than liquid-free olives such as sliced olives, which tend to last 5 days at best.

How to Tell if Black Olives Have Gone Bad

Like many of us, you may not opened a jar of black olives and left them in the refrigerator. Now you want to know if they have gone bad or not. Well, there are a few clues to look for:

Round Lid

Look at the lid on your jar of olives. If it’s round & dome-shaped instead of completely flat, be cautious because this is a telltale signs of spoilage.

A round lid means that the jar has not been sealed properly. Because of this the olives may have been exposed to all kinds of things that can cause them to go bad. Also, if the lid doesn’t pop when you open it, this is another sign of a poorly sealed jar.

Mold on Olives

There may be a layer of white mold that is sometimes slimy or fuzzy. This is a good indication that your olives have gone bad and should be discarded right away.

Rancid Smell

If your black olives have gone bad, they will produce a foul, pungent smell. It’s pretty much unignorable, and it means that those olives, unfortunately, are no good anymore.

White Stuff on Olives

Contrary to what you may think, you shouldn’t discard your olives if you see white spots on them because they are totally harmless. They are just a result of the fermentation process, or sometimes they can be solidified fat as well. In both cases, just wash them away and your olives are safe to eat.

What Happens If You Eat Expired Black Olives?

So, what happens if you’ve accidentally eaten black olives that have gone bad?

You may feel some stomachache and/or nausea, which should be fine after a day or so, during which you should rest as much as possible. However, you can get food poisoning from eating bad olives if they have mold growth on them. In this case, you may experience some symptoms such as vomiting and/or diarrhea. I would advise you to consult a doctor immediately if you suspect that you have food poisoning.

How to Store Black Olives

If you want to prolong the shelf life of your olives, it’s important to store them properly. There are some key factors you need to understand when storing them.

Right Temperature

If you haven’t opened your jar of olives yet, then you can store them at room temperature in your pantry. However, you should be careful about the temperature of your pantry, it shouldn’t be hotter than 75°F.

Another thing to keep an eye out for is sunlight and heat. Even though your jar is unopened, exposure to sunlight or any kind of heat source may impact the taste. Thus, a dark, dry, and cool place is the way to go for your unopened jar of olives.

After you have opened the jar, you should always keep it in your refrigerator to prevent spoilage.

Tight Seal

You should always tightly close the lid of your olive jar, otherwise they may expire faster or even spoil due to environmental factors (such as mold growth, harmful airborne bacteria etc).

If, by any chance, you cannot find the lid of your jar or thrown it away for some reason, you can always transfer your olives into an airtight container (with their brine unless they are liquid-free).

Full Brine Coverage 

You should always store your black olives submerged in their own brine solution, even if you transfer them to a new container. Otherwise, they will definitely expire much faster.

If you bought the liquid-free type, then all you have to do is keep them in an airtight container in the refrigerator and they should be fine.