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Can Sesame Oil Go Bad?

We all know how this goes. You buy a bottle of sesame oil with the best of intentions. You plan on adding this new recipe to your weekly meal plan, and you need that oil for it. You use it once or twice, and the leftover oil sits in the cabinet untouched ever since.

Then, a couple of months later, you need sesame oil once again, and you remember you have an opened bottle in storage. It sits open for quite some time already, so you’re not sure if it’s okay to use it or not.

That’s where this short guide comes in. In it, we talk about going bad of sesame oil, its shelf life, and storage methods. After reading it, you will know what to do with that oil.

Toasted Sesame Oil
Image used under Creative Commons from Adam Engelhart

Can Sesame Oil Go Bad? How To Tell That It’s Bad?

Obviously, sesame oil can spoil. If there’s mold in the bottle, the oil changes color, or there’s sediment on the bottom of the bottle, it’s safe to assume that it’s off. However, such drastic changes aren’t that common for oils.

As long as you keep the bottled sealed well, chances of any of that happening are slim. Nevertheless, if that’s the case, discard the bottle.

What’s much more probable is that the oil goes rancid ([WIKI]). Rancidity is oxidation or hydrolysis of fats that were exposed to air, light, moisture, or bacteria. Even if you follow the storage practices to a T, the oil will still have contact with air (that’s in the bottle) and sometimes light (when you open the cabinet). And the more the oil is exposed to those, the faster it oxidizes.

Fresh sesame oil in a small glass bottle
Fresh sesame oil in a small glass bottle

Okay, so you know that the sesame oil oxidizes over time. What does that mean, practically speaking?

Rancid oil changes in terms of taste and odor. If the oil’s flavor or smell is much worse than they were when you first opened the bottle, the oil is rancid. Same thing if it’s a fresh bottle that you just opened and doesn’t have that nutty and toasty (if it’s toasted) aroma, smells acidic, or tastes bitter.

In short, if there’s something noticeably wrong with the smell or taste, it’s safe to assume that the fat has oxidized.

Should you discard rancid sesame oil, you ask? There’s no straightforward answer to that question. As far as we know right now, rancid oil isn’t unsafe to eat ([WIKI]). That said, if it doesn’t smell and taste good, it will likely ruin the dish you’re preparing. Thus it’s probably better to get rid of it.

Last but not least, please remember that rancidification is an ongoing process. When it just starts, the smell or taste might not be of top quality, but still good enough to use. But as time goes by, the oil will only get worse.

Table ready for cooking
(credit: Le Creuset)

How Long Does Sesame Oil Last?

Like peanut oil, canola oil, or pretty much any other oil, a bottle of sesame seeds oil comes with a best-by date. That date is a rough estimate of how long the oil will retain good quality provided it’s stored reasonably well.

And since those estimates are quite safe, more often than not, you can easily store the oil for a couple of extra months, especially if you follow good storage practices.

Generally speaking, toasted sesame oil tends to last longer than the regular one. It retains quality for between 1.5 to 2.5 years, depending on the packaging, while the pure one keeps for between a year and two. Again, that info is included in the date on the label.

Organic sesame oil in a bowl
Organic sesame oil in a bowl

Once you open the bottle, the oil gets access to fresh air, and the oxidation process speeds up. Check the label if it says how long the oil will keep quality after opening. It’s usually between 2 ([MO]) and maybe 4 months.

Of course, that doesn’t mean the oil will spoil or be completely rancid after that period. But its quality will suffer, and you might no longer find it good enough to use. In short, it’s up to you if you decide to keep using that oil.

For me, if it still smells and tastes okay, I continue using it until I finish the bottle or it’s not acceptable anymore.

Speaking of shelf life, the better you care for your oil, the longer you will enjoy its taste. Let’s talk about that.

Sesame oil in a corked bottle
Sesame oil in a corked bottle

How To Store Sesame Oil?

The storage guidelines are pretty much the same for all kinds of sesame oil, no matter if it’s cold-pressed, toasted, or else.

Keep the oil in a cool and dark place ([MO]). A dark cabinet in the pantry is perfect, but the kitchen can work too. Just don’t store it in a place where the temperature fluctuates.

For an opened bottle, remember always to seal it tightly and stick back in storage after use. And when cooking, don’t leave it unsealed on the counter. Pour how much you need, and put the rest into the cabinet.

Last but not least, unlike tahini, opened sesame oil doesn’t need refrigeration.

In a Nutshell

  • Sesame oil goes rancid if exposed to air, light, moisture, or bacteria for a prolonged period. Rancid oil smells and/or tastes off, and it’s probably best to get rid of it.
  • You can easily store sesame seeds oil for a couple of months past the date on the label if you store it properly.
  • Keep the oil in a cool and dark place, always sealed tightly.