Jarred tahini -- how long can it be stored?

[toolprincess]

I have a jar of tahini that I picked up at a Lebanese market last year. I have never opened it. Is it still good? How can I tell? If the oil has separated is that a bad sign?

(I am always buying things I "have to have" and then forgetting or never getting around to the recipe that called for that ingredient - that I am sure could be a whole other topic).

[Pam R]

The oil separating out is normal and happens when the product is still good. I think the best thing to do is smell it -- sesame will go rancid and you should be able to smell it if it has.

[mendonoma]

As far as I know, tahini keeps forever (or for a very long time). I just used some that I have had refrigerated for over 10 years (!) and it was just fine. It was excellent 'quality' tahini (bought in bulk from Kalustyans). The oil always separates from the solids...and I think this is why it keeps so long. You can either pour off the oil or incorporate it into the solids (I poured off most of it). Joya is the best easily accessible brand...tahini must be made from roasted sesame seeds to have the best taste....and, unfortunately, most of the organic brands do not roast the seeds. Hopes this helps you.

[Lisa Shock]

Oils can go rancid (microbial rancidity, oxidative rancidity, hydrolytic rancidity) long before the human nose is able to detect an off odor. I don't like to keep any ground nut/seed or oil longer than 6 months, even if sealed. And, I treat my opened oils with BHT to help prevent cross-linking -something I picked from reading Durk and Sandy in the early 80's.

Edited May 13, 2011 by heidih
Fix link (log)

[Pam R]

Oils can go rancid (microbial rancidity, oxidative rancidity, hydrolytic rancidity) long before the human nose is able to detect an off odor.

Interesting -- are there other signs that it's rancid or is it undetectable? And will keeping open containers in the fridge keep it longer?

[Chris Hennes]

If you can't smell or taste the rancidity, does it matter?

[Lisa Shock]

The compounds that are formed by the changes are known carcinogens.

[GlorifiedRice]

Rancid oil can prevent the absorpton of vitamin K

[gfweb]

References please.

[Mjx]

The compounds that are formed by the changes are known carcinogens.

Rancid oil can prevent the absorpton of vitamin K

Interesting; please list some studies, since both these items are news to me!

[Lisa Shock]

It's covered in the book I linked to above, Life Extension: A Practical Scientific Approach by Pearson & Shaw, originally published in 1982, IIRC. They have legitimate scientific studies backing up the work, and a huge index at the back of the book. Sorry, not able to reference anything right this minute.

[Mjx]

I have a jar of tahini that I picked up at a Lebanese market last year. I have never opened it. Is it still good? . . . .

Is there a 'consume by' date on it? Not exactly a hard and fast guideline, but if the date on it sometime in, say, 2015, it should be fine.

It's covered in the book I linked to above, Life Extension: A Practical Scientific Approach by Pearson & Shaw, originally published in 1982, IIRC. They have legitimate scientific studies backing up the work, and a huge index at the back of the book. Sorry, not able to reference anything right this minute.

Update me when you find those studies! That book's science is not unimpeachable, so some original research would be particularly interesting.

[Darcie B]

I've kept tahini for up to a year in the refrigerator after it was opened and which had been in the pantry for a few months before that and it *seemed* fine.

Personally I'd rather take my chances with potential rancidity that I couldn't detect over adding butylated hydroxytolulene to my food. But that's just me.

Edit to add pantry storage time.

Edited May 13, 2011 by Darcie B (log)

[ScoopKW]

I've had tahini last in our pantry for a few years. (We made the mistake of buying the industrial-sized jar, thinking we'd get enough eggplants that summer to make THAT much babaganoush.) Kept cool and dark, but not refrigerated. Tasted fine at the end -- not at all rancid.

Remember, this stuff was invented for use in North Africa and the Middle East centuries before refrigeration. Unless it tastes off, keep using it.

[Lisa Shock]

The stuff was invented during a time when the average lifespan was 22 years. If you'd like to emulate that system, that's your choice.

And, like I said, there can be considerable damage to the oils (rancid is a vague term used to cover several different processes of degradation of oils) before it's possible for the huiman nose to smell anything.

HERE is a link to modern research into rancid oils. As many of you know, a lot of research that occurred prior to the Internet era isn't documented in it. Consumption of rancid oils has been considered to be a health risk for decades in western medicine. It's understood that rancid oils are part of the diet in developing nations because they don't have access to good transportation and storage facilities. But, just because millions of people are forced to eat the stuff or nothing )much like contaminated water supplies) doesn't make it good for them.

Rancid oils aren't poisonous to the point of killing people, but, they certainly don't do anything to optimize lifespan.

(edited to add link)

Edited May 13, 2011 by Lisa Shock (log)

[Toliver]

Rancid oils aren't poisonous to the point of killing people, but, they certainly don't do anything to optimize lifespan.

Thank you for the info.

Does refrigeration help delay the oil from becoming rancid? If so, how much time does it buy?

[Lisa Shock]

Rancid oils aren't poisonous to the point of killing people, but, they certainly don't do anything to optimize lifespan.

Thank you for the info.

Does refrigeration help delay the oil from becoming rancid? If so, how much time does it buy?

Refrigeration does slow things down considerably, so does limiting exposure to air. Try to keep containers almost full and use a vacuum sealer if you have one. I can't give precise predictions because there are too many variables, but, I store all of my oils and nuts/seeds in the fridge or freezer. (I also add a little BHT to oils when I open the containers and write an 'opened on' date on each package.) I don't currently have access to equipment to test results, but, my feeling is that you can get an extra six months or so out of a product.

That said, I try not to buy oils and oily items in bulk quantities unless scheduled for a task in the near future.

I also run my home fridge like a commercial one, FIFO rotation of new items to the back and a weekly cleaning & inspection of dates and quality. I attend a couple of potlucks each month which conveniently give me a way to use up oddball items.

[toolprincess]

I checked the bottle and found that it does have a Use by date of 3/2012.