Have you ever been to the olive market in Greece or Spain? The smells, the taste, the texture…It is hard to believe that olives come in so many shapes, colors, forms, and tastes.
But, since going to Greece to buy fresh olives is not an option for most of us, we are stuck with canned or jarred olives. So, what happens with olives you bought in a jar or a can once you open them? Let’s explore all possible answers to the question: do olives go bad?
Do Olives Go Bad?
The fact of life is that olives are food, they are organic, and regardless of how they are preserved, at some point, they can go bad.
They go bad if they have not been preserved correctly, they have not been stored appropriately and they have been handled in such a way that they have been contaminated by harmful bacteria.
It takes a lot for olives to go bad. According to the researchers, the olive environment is not good for the presence of bacteria that can spoil preserved olives.
The reason is that the preserved olives contain inhibitory compounds like polyphenols, low nutrient content, high content of salt, low pH, bacteriocins ( toxins produced by certain bacteria that inhibit similar or related bacteria), or the preservatives that are added to the packed olives.
How Long Do Olives Last?
Not all olives are the same so there is no easy answer to the question of how long can they last. Green olives last a different amount of time than black, ripe olives.
The quality of brine, the fermentation salty water, affects the duration as well. Preserved in the refrigerator or in the pantry also affects how long olives last before getting spoiled.
Interestingly, some research shows that it is more important to preserve olives in low pH brine than to keep them cool.
Olives (black/ green) (whole/ pitted/ sliced)
Olives (with brine liquid or oil) (unopened)
|Best by date + 3 to 6 months||–|
|Olives (with brine liquid or oil) (opened)||–||
1 to 3 weeks; up to 6 and 12 months for specific brands
Olives to-go (sliced, without liquid) (opened)
|Best by date + 1 to 2 months||–|
|Olives to-go (sliced, without liquid) (unopened)||–||
2 to 3 days
Olives (from an olive bar)
|–||1 to 2 weeks|
|Stuffed olives (unopened)||Best by date + 1 to 2 months||
Stuffed olives (opened)
|–||1 to 2 weeks|
|Homemade stuffed olives||–||
3 to 5 days
You might find other sources with different information. Olive manufacturers in particular disagree on the length of time olives can stay fresh after opening a jar or can.
The rule of thumb is to read the label on the can or a jar and follow it. The reason for different opinions is probably the different procedures for olive conservation and the preservatives used to ensure freshness.
Ripe olives are often preserved and sold in olive oil, which is an excellent medium for conservation as it keeps olives from being exposed to air, which is needed for the development of bacteria. Once opened, olives in oil have pretty much the same shelf life as those preserved in brine.
Tips to tell if olives have gone bad
The first hint that your can or jar of olives is only good for the garbage is the rusty or rounded lid or a can. It means that the conditions inside are gone bad and the bacteria are having a blast. The same goes for the leaking can or jar. It means that the can or jar are not sealed anymore and the bacteria have gone in.
Once you open the can or jar of bad olives, the first thing that will hit you is the smell. Rotting olives smell, well, like rotting fruit. Olives in a can sometimes have a metallic smell, but that is probably from the metal in which they have been stored too long or improperly.
Besides bacteria, olives are also prone to mold infestation. If the jar was opened and stayed for a while in the fridge and pantry and has grown a layer of mold, get rid of it. While not all molds produce harmful toxins, do you want to risk it? It is just not worth it.
Olives conserved in oil have a different problem. If the jar or a can have been stored in a warm environment, the oil might turn rancid and that smell is so unappetizing. It does not mean that olives are automatically bad, but again, if the oil is spoiled, it is very likely the oil was not doing a very good job of preserving olives.
If you opened the jar, ate a few olives, and left others for later, they need to be completely submerged in the brine. If they are not, they are not being conserved and will spoil much faster.
7 Tips to store olives
- Keep an unopened can or jar of olives in a cool, dark place, like your pantry. It varies between manufacturers and their conservation process, but olives in brine can stay unopened for several years. Olives in oil can last only a few months. Once the jar is open, olives in brine can last for a few months, but those in oil should be consumed in a couple of weeks.
- Once your jar is open, reseal well the left-overs, making sure that all olives are still covered in their liquid. Most olive manufacturers suggest keeping the olives once their container is open in the fridge. Depending on the quality of their conservation, they might be stored out of the fridge if the temperature is not higher than 68°F or 20°
- If you opened a can of olives and did not finish them all, you will have to de-cant them in a well-sealed glass jar. Again, they have to be covered in their liquid to stay preserved. It goes both for olives in brine and those preserved in oil. It is strongly suggested to store them in the fridge.
- In the places where fresh olives are growing, many people are tempted to do the preservation themselves. Fresh olives cannot be eaten fresh, they are too bitter. They need to go through the process of preservation, which not only makes them less bitter but keeps them fresh longer.
While the process of preserving olives seems pretty straight-forward, it is important to follow instructions when it comes to the strength of the brine as well as the hygiene during the same process. Very often it is the process that introduces the harmful microorganisms. If the brine is strong enough, the bacteria can be eliminated. If not, you risk a bad stomach upset.
- Black, ripe olives are often preserved in oil, but even they have first to be made less bitter in salty water.
- Greeks have been conserving olives for thousands of years and they came up with some original ways of conserving. One way they treat Kalamata olives is by keeping them in the seawater for months and then pickling them in wine vinegar and spices. Modern Greek olive exporters say that olives preserved like this do not need to be refrigerated after opening the jar.
- Any method of storing olives is only as good as their original preservation. Whenever you can, buy the best quality olives you can afford. Not only they taste better, but they will last longer.
The risk of consuming expired olives
You must really love olives to risk eating them after their expiration date. It is possible that they managed to stay good if they were in the original unopened jar or can and stored in a cool, dark place.
But if not, you risk at least an upset stomach, feeling like having food poisoning. In worse cases, if your olives were really bad or you ate too many, you might get bad diarrhea or vomiting and risk dehydration. It is also possible to contract botulism from improperly prepared or stored olives.
Can you freeze olives?
Olives are fruits and can be frozen just like any other fresh fruit. Wash them well and store them in a well-sealed container. Leave about half an inch empty at the top in case they expand during freezing.
It is a good idea to brine the olives before freezing to eliminate olives’ slightly bitter taste. Make the brine by mixing a gallon of water with four ounces of salt. Boil olives in the brine for about 15 minutes, then rinse in cold water and store in an airtight container before freezing.
Brining greatly improves the texture of olives, which sometimes get dehydrated when frozen, becoming shriveled and soft.
Experienced chefs suggest mixing the brine with your favorite spices before boiling olives in it.
It is also possible to freeze preserved olives from a can or jar. Since they can lose their texture from freezing, one tip is to place them in muffin tins and top them with water before freezing the whole tin. Once frozen, you can place your ‘olive muffins” in a tight container or a Ziploc bag.
Olives are considered extremely healthy and are part of the healthy Mediterranean diet. They are a great addition to many dishes and make an excellent martini even better.
While olives can get bad, they can stay fresh for a long time if they are well-preserved and stored according to the advice on a can or jar. It is important to purchase good quality olives which were conserved in the best way to create the environment that keeps olives from getting affected by harmful bacteria.
After opening a jar or can, the leftover olives should be left in their original liquid – brine or oil. While some manufacturers suggest that it is fine to keep them out of the fridge, it is better to err on the safe side and place the leftovers in the fridge. So, can olives go bad? Yes, but there is much you can do to prevent it.