Oil is one of those things that is very complicated to store. There are a lot of factors determining how long you can keep oil including the container, storage temperature, whether it’s been opened or not and of course the original date of manufacture. Sesame oil or sesame seed oil is no exception to this and has the same considerations if you intend to store it.
Sesame oil is a vegetable oil derived from sesame seeds. Often used as cooking sesame oil is also very useful as a flavour enhancer due its unique nutty flavour and aroma. It is one of the oldest known vegetable based oils. Mass production is hindered by the difficulty experienced in harvesting the sesame seed and processing it. To our knowledge sesame was cultivated more than 5000 years ago and was favoured for its drought resistance. According to historians sesame was grown in what is modern-day Afghanistan, Pakistan and India.
How To Tell if Sesame Oil is Rancid
Sesame oils that appear darker in colour than usual are likely rancid. If the oil looks amber as opposed to light golden in colour it may be rancid. A quick image search online can provide you an image to compare colour against if you’re not sure. You may find that containers of sesame oil develop a sticky substance on the outside, this is another sign of the oil going rancid. Fresh sesame is fragrant and even described as having a nutty aroma. Rancid sesame oil can be described as smelling bitter and soapy. Any harsh smell in sesame oil means it likely rancid. If you’re not sure by looking and smelling the oil you can try a taste test. If it tastes sour or bitter, your sesame oil definitely unsafe.
Best Container for Sesame Oil
Sesame oil is mostly sold in small glass vials and these are great for storing sesame oil. You can find larger amounts of sesame oil sold in cans which is an ideal storage option when unopened but once the oil is opened you may want to transfer the oil to a glass container. There is nothing wrong with storing sesame oil in a plastic container. Ideally, you want to sterilise the container before use. It is also critical to your storage efforts that the storage container of choice is completely airtight.
What To Guard Against
There are 3 things you want to protect your sesame oil from to prevent it from going rancid. Light is the first natural enemy of sesame oil. Before you put it in a dark container just remember you will use a visual test to check if your oil is rancid so a dark container is not recommended. This is also why glass is recommended over plastic. Another enemy of sesame oil is warmth. Be sure to store your sesame oil away from places that are warm or generate warmth such as the top of a refrigerator or storage above a stove even with a range hood installed. Finally, air is another natural enemy of sesame oil. The more air present in a container the greater the chances o the oil going rancid.
Before You Store Sesame Oil
The most important thing to check before storing sesame oil, sealed or opened is the original date of manufacture and not the best before date. While best before dates are well-intentioned pieces of information you should start counting from the date of manufacture. You can see this on the container though it may be labelled differently in different countries it usually appears above the expiry or best before date. Avoid mixing new sesame oil with older sesame oil or reusing a container for new oil without washing out and sterilising the container. Even the smallest amount of older sesame oil can contaminate the new sesame oil and it will go rancid faster.
Sealed In Fridge
It’s quite normal to buy sesame oil long before you need it and in this case, you will be keeping it sealed. If you are one of those people you will be happy to know that sealed sesame oil can keep in the refrigerator without going rancid for 2 years. Remember to count from the date of manufacture and not the date you purchased it. As long as the container is not tampered with in any manner expect to have the oil with you and usable for two while years.
Sealed At Room Temperature
If for some reason, you choose to store your oil at room temperature say in a pantry or storage cupboard you can expect to get a storage life of 1 year. Just remember this applies if there is no light or heat source in or near the storage area. It’s really important to remember that sesame oil is kept at room temperature in store shelves. Storing it at room temperature gives you a consistent measure of how long it will last. For example, if you buy sesame oil that was manufactured 3 months ago you can expect it to keep for a further 9 months unopened when stored at room temperature. Contrast this with storing the same sesame oil in the refrigerator. I would love to tell you that you get 18 months but it’s not that simple.
Opened In Fridge
If you’ve used some of your sesame oil and want to store the rest in the refrigerator, no problem. After being opened sesame oil can be stored in the refrigerator for up to 2 years. This is provided of course that all other storage instructions are followed religiously. It’s best to use sesame oil as soon as possible after opening but it is proven to keep just as well opened as unopened in the refrigerator. This is due to the absence of both light and heat in the refrigerator.
Opened At Room Temperature
If you’ve opened your sesame oil but want to store it at room temperature then you will have to use it a little bit quicker than you would if you refrigerated it. Opened sesame oil keeps at room temperature for 6 -8 months. As you can see the warmer temperature has a drastic effect on the ability of sesame oil to keep. So too does the introduction of air into the container.
In conclusion, sesame oil does keep for long if it is stored appropriately. It’s best stored in airtight glass containers in a cool dark place. Avoid light and heat when storing it. In the refrigerator, it will keep for 2 years. If stored at room temperature it will keep for a year unopened and 6-8 months when opened.