Sesame oil is used for cooking and as a seasoning, particularly for Asian foods.  One of the most common questions about it is if it goes bad, and how long it can last.  I’m here to answer that question.

Quick Answer 

Of course, sesame oil doesn’t last forever.  What happens is that it goes rancid, or oxidizes.  This changes the taste and smell of the oil:

• An unopened bottle of sesame oil can become rancid after about a year after its “best by” date
• An opened bottle can become rancid about six months after you open it
• Oxidization happens because of both air and light contamination. 

Here are some helpful hints to keep your sesame oil lasting as long as possible, and how to know when it’s ready to throw out.

Does Sesame Oil Go Bad? How Long Does Sesame Oil Last?

Sesame oil can potentially last for over a year, but what are the options for storing it?  Should you store it in the pantry, in the refrigerator, or freezer?

How Long Does Sesame Oil Last Outside?

While it might not seem like leaving your sesame oil outside will harm it, exposure to light, especially sunlight, increases the rate of oxidization.  This can lead to the oil going rancid faster.

• If placed in a room with direct sunlight, sesame oil lasts about a month or two
• Your sesame oil can last six months after the day you open it
• Sesame oil can last up to two years in a pantry if unopened

• You should store sesame oil in a place that is cool, dry, and dark to last as long as possible
• Keep the lid tightly closed as much as possible, to avoid any contaminants getting in
• Smaller bottles will be finished quicker and will have less time to spoil than larger ones

How Long Does Sesame Oil Last in the Fridge?

Storing your sesame oil in the refrigerator makes it last longer because the coolness of the fridge slows down the chemical reactions that lead to oxidization.

• Sesame oil stored in a refrigerator can last a year if unopened, and around two years if unopened.  After about a year or so, it might be a good idea to check on it, even if you haven’t opened it

• Storing your sesame oil in the fridge may make it turn cloudy or even solid, but this doesn’t mean it’s gone bad.  Letting the container warm up to room temperature will restore it to normal

How Long Does Sesame Oil Last in the Freezer?

Sesame oil might last a long time in the refrigerator, but what about the freezer?  If keeping your sesame oil cool is a good idea, wouldn’t keeping it colder be better?

• What seems like a logical conclusion isn’t, in this case.  Frozen sesame oil turns into a solid, meaning that you’d have to bring it out and melt it for a few hours when you want to use it.  A few minutes to an hour or so likely won’t freeze it too much
• Sesame oil freezes at 21 degrees Fahrenheit (or -6 degrees Celsius, for the non-Americans)

Overall, the best place to store your sesame oil is in the refrigerator, although storing it in a darkened pantry or cupboard is also a good idea.

How Do You Know if Your Sesame Oil is going bad?

Sesame oil can turn rancid even with all precautions taken.  Here are some of the signs that it’s going bad.

The oil smells or tastes strange

When sesame oil turns rancid, it’s because the fats inside the oil are oxidizing, or breaking down.  This makes the oil give off a bitter smell and taste.

Stickiness

If your bottle or container has a sticky residue on it, then there’s a good chance that the oil inside has gone rancid.

Color

Does the color of the oil seem a bit darker than normal?  You might want to check it out before you use it.  This is another effect of the fats inside the oil breaking down.

What is the “best by” date?

If you take a good look at the container the oil came in, there will be a recommended use-by date.  This isn’t a guarantee, however; it’s more of quality assurance.

How long have you had it?

If you’ve had your oil for around two years it’s a good idea to throw it out, even if you stored it properly and haven’t opened it.  The oil will break down no matter how it’s stored.  Proper storage just makes sure it stays good for as long as possible.

How To Store Sesame Oil?

Storing sesame oil can be done by sticking it in a dark pantry, cupboard, or in the fridge.  Here are some tips and tricks.

Smaller is better

A small bottle of sesame oil will be used up faster than a large one, which gives it less time to turn rancid.  It also saves space.

Don’t open it until you’re ready to use it

While this may seem fairly obvious, sesame oil is more likely to last longer if it’s in an unopened bottle.

Make sure the cap is on tightly

If the cap is not securely sealed, then air and airborne contaminants could easily get into your sesame oil.  Check that bottle before you put it away.

Keep the oil away from any heat sources

Exposure to heat hastens the process of going bad in the same way that exposure to light does, so don’t store it next to or just above your stove

Can You Freeze Sesame Oil?

Sesame oil technically can be frozen without harming it, but since it’s a liquid designed to be poured into your food or the pan, it doesn’t make a lot of sense to freeze it.

• To pour frozen sesame oil, you’d have to thaw it out.  You’d have to wait a few hours to use it, increasing the amount of preparation time needed
• It’s easier to put your sesame oil in the fridge than in the freezer if you want it to last

Frequently Asked Questions About Sesame Oil’s Shelf Life

Does toasted sesame oil have a similar shelf life to regular?

Opinions seem to be varied on this.  Generally, the consensus is that toasted sesame oil has a slightly shorter shelf life than the normal type.  I recommend paying attention to the “best by” date and testing the oil before you use it.

What is cold-pressed sesame oil, and is its shelf life different?

Cold pressing is a method of extracting sesame oil by pressure, rather than heat, preservatives, or chemicals.  Basically, it’s the purest oil.  Due to the lack of preservatives, it can last around six months in a pantry, and one year refrigerated.

Is rancid sesame oil safe to eat?

Sesame oil becomes rancid gradually, so at first, it probably will be safe to eat.  It will taste and smell funny, though.  As time goes by and the rancidity worsens, it’s definitely not a good idea to eat it, but opinion seems to vary on whether it’s actually safe to eat or not.

Wrap up

The next time you open up a container of sesame oil, take a closer look at it.  Check out the “best by” date, maybe take the time to think about how long you’ve had it.  Sesame oil might not last forever, but if you store it in the right way it will last a good long time.