Drying Tomatoes And Storing In Oil

*Updated 9/3/11 to contain even more safely information I’ve found (which confirms for me that this is still the best way to keep dried tomatoes!)*


This is how I’ve stored my dried tomatoes for years: in a vintage canning jar covered in olive oil and sitting in a kitchen cabinet. I’ve found them much easier to use this way: cut up in Italian pasta, over salads, and in dips, just to name a few.

I learned this technique by reading a well-know local food preservationist/writer, Jan Roberts-Dominguez in the Oregonian in the 1990’s. I actually taught myself to can using some of her articles and many of her recipes are my favorites even now.

But, here’s a note on safety: Many of you know I’m big on food safety, and I don’t do things based on the “I’ve done it for years and it’s never killed anyone” train of thought. However, this is a time-honored preservation technique that I feel good about for two reasons: tomatoes are naturally acidic (and I never add any fresh garlic or herbs), and I dry them until they are pliable, but no liquid comes from them when I test them with my fingers. I also, as per Ms. Dominguez’s recommendation, dip them in red wine vinegar to help extend their shelf life (and just so happens to increase the acidity).

However, about a month ago, I came across a newsletter that said the National Center For Home Food Preservation was no longer recommending storing dried tomatoes in olive oil. Why?

“Preserving tomatoes in oil is currently not recommended. Oil may protect botulism organisms trapped in a water droplet. Furthermore, oil may have a deleterious effect on lid gaskets and the at least one manufacturer of home canning lids recommends against it.”

You can imagine I was NOT happy with this. Especially since:

  1. The tomatoes are dried and don’t contain “water droplets” and
  2. The oil doesn’t touch the lids and I don’t use canning lids- I use vintage metal/plastic lids.

But mostly I wasn’t happy with this because when I tried to research this new recommendation, I wasn’t able to find any other site or research to back up this claim.


So I emailed Ms. Dominguez (hey, I’m a fan…) and asked if she had heard this and what her thoughts were. She had not heard this and basically said that if the tomatoes are truly dry and not packed with any fresh herbs or garlic there should be no problem. The vinegar dip she recommends also helps tip the acidity level.

So there. I’m still going to store my dried tomatoes this way, but I am giving you all the information I have at this point so you can make your own informed decision.

But let me tell you- these are sooo easy and tasty and a fraction of the cost of store-bought.

Not that I’m trying to sway you or anything.

9/3/11 update: I found this information that mirrored my own from the 2010 book, How to Store Your Home-Grown Produce: Canning, Pickling, Jamming, and So Much More by John and Val Harrison:

For years we stored in oil by simply placing the produce in a sterilized jar and filling the jar with oil, agitating to get any air bubbles out before sealing…when we published this on our website we were deluged with emails warning that we could get botulism from this…

When we researched this…we discovered that it was first mentioned on a Canadian website in reference to an outbreak of botulism from a restaurant…this was picked up and repeated…until it became a fact as far as casual searchers were concerned.

(We) decided to consult a food scientist directly. He explained that there was a theoretical risk that small droplets of water adhering to the vegetable would provide a growing medium for botulism. He couldn’t quantify the risk, not being a statistician, but comparisons with being struck by a meteor…were mentioned. He wouldn’t go on record as saying it was safe, although he said he would have no concerns personally about using the method.

The authors go on to say that they tired of the endless arguing on their site, so they now only recommend a “hot oil” method (whereby you heat the oil to 140 degrees before pouring it on the tomatoes and sealing), though there is some loss of flavor.

So now you are able to make an even more informed decision- you may heat your oil or not as you use your own common sense and experiences. As for me, I’m glad to know I can feel good about continuing to store my dried tomatoes this way.

I use only plum tomatoes for dried tomatoes to store in oil. If I were going to dry them crisp and make tomato powder, it wouldn’t matter as much.

I wash them, cut the top core off and cut them in half. I then remove as much of the seeds as I can.

It sounds tedious, but goes rather quickly. I line them up on my dehydrator tray, cut side up. This is important, otherwise you’ll get a lot more juice run-off as they dry and the cut side would stick to the tray, making them harder to turn as they dry.

As you can see, I really pack them in there because they shrink as they dry.

I dry at the manufacturer’s recommended 135 degrees and I don’t look at them for about four hours. That’s when I do the first switch: I turn them over and turn the trays around. None are usually dry yet, except maybe a few really small ones.

Let dry for another 1-2 hours before checking again. At this point, there will be some dry ones and you’ll need to remove theses and continue drying the rest.

This is what they should look like:

Dry and leathery with no moisture coming out from them when you push them with your fingers. You should be able to bend them like this.

If some get a bit crisp, it’s OK, but don’t let them all get that way- there’s no amount of oil that will soften them up again.

While the others continue to dry, start putting the dry ones in a jar. First, fill a little bowl with red wine vinegar and grab some tongs.

Dip the dried tomato halves into the vinegar and then let the vinegar drip for a minute before placing in the jar.

Continue dipping, letting them drip, and placing in the jar until all the tomatoes are gone.

Add olive oil to the jar until the tomatoes are covered. This is quite a bit of oil, but you will be able to use the oil in salad dressings and such as you use the tomatoes.

It’s not like it’s wasted or anything.

Make sure the tomatoes are completely covered in olive oil.

When the next bunch of tomatoes are dry (they never dry all at once, since they are all different sizes and thicknesses…), just continue to “dip and drip” each one in the vinegar and place in the jar, covering the new additions with more olive oil.

When the jar is full, store it in a dark, cool place.

Hopefully where you can reach it easily, because you will probably be using these a lot.


This is linked to:

Tasty Traditions

Recipe Swap Thursday @ Prairie Story


  1. Anonymous says

    There was a discussion about this on the Harvest forum and this reference was cited, your method uses just vinegar, even better. “THE U. C. DAVIS METHOD FOR PACKING DRIED TOMATOES IN OIL
    If you’d like to pack dried tomatoes in oil, follow these steps:
    After the tomatoes are dried, it is recommended that you place them in a bowl and sprinkle with diluted (one part vinegar, one part water) distilled white vinegar. This acidifies the tomatoes and also adds back some moisture, for a chewy texture.
    Empty bowl onto paper towels and pat tomatoes dry.
    Pack tomatoes lightly into clean pint or half-pint jars. At this stage you may add herbs or spices, dried only. Cover with oil
    to ½ inch of the rim of the jar. At room temperature, oil may become rancid. This is not unsafe, but undesirable. If garlic is
    desired, U.C. Davis recommends acidification of the garlic by marinating with fresh herbs and vinegar 24 hours, checking to
    see if vinegar has completely penetrated before putting in oil.”
    What brand is your dehydrator, I have an old Montgomery Ward(!) one but the trays look just like yours pictured.
    I have really enjoyed your recipes, the green beans with garlic–YUM.

  2. says

    Thank you very much for this step by step process. I have a whole list of items I want to try more and more so I cook more from scratch, etc. So thank you. Do you think you could offer a pdf print of this too?

  3. Jami @An Oregon Cottage says

    Oh, thanks so much, Lea for that UC Davis recommendation- it’s nice to have another source.

    Ellen- I didn’t think about doing it because it wasn’t a “recipe” as such, but I’ll try to get it into some type of recipe format. :-)

  4. Jami @An Oregon Cottage says

    I’ve never dried things in my oven, but I’ve read that you can, it just takes longer. Google it and I bet there’ll be instructions!

    I use an Excaliber Dehydrator.

    • Eliza says

      I just finished drying my tomatoes in the oven I did 250 for about 8 hrs. It worked beautifully, they are delicious. I packed them in them in oil and rosemary. They are so delectable!

      • says

        Great to know about the oven method, Eliza – thanks! I hope you used dried rosemary, though, with your tomatoes? Adding anything fresh introduces moisture and the chance for botulism, so you’ll need to refrigerate if it is fresh rosemary (and some sources say even with refrigeration you should be careful!). I’m hoping you used dried, though! :)

  5. says

    I thoroughly enjoyed reading this post with all the background information. I am going to give this a try! Thanj you for sharing. ~Prairie Story

  6. says

    Thank you for sharing this post. I didn’t know how to dry tomatoes and now I so excited. I cant wait for Spring to plant my tomatoes. I like to can tomatoes but I prefer dried tomatoes for pizzas, etc. Thanks again for sharing and linking up.

  7. says

    I most DEFINITELY have to try this! We dry a lot of our tomatoes so we can use them in pastas and salads. I’ve been contemplating doing this so thanks!

    • Jami @ An Oregon Cottage says

      Aren’t they just a little burst of summer in the depths of winter? I love how easy they are to use, too! Glad you tried them!

    • says

      The jars aren’t sealed, Susan, in any other way besides screwing them on – the olive oil is providing the ‘seal’ to the tomatoes in this case. The storage is the same whether the jar has been opened previously – 6 months ideal, but we use them up to a year later. They are darker and not as pretty, but give all the great flavor, still. :)

  8. Hendrika says

    Hi Jami, Just came upon your site while looking up directions for drying tomatoes. Had already planned to store them in oil but wanted to verify methods. Your site did the trick. Thanks. Originally from Holland my family never “processed” pickles either. They were put in vinegar with spices and merely covered with a topping of “salad” oil (I use Canola). works great too. The first batch of tomatoes are drying at this moment and I cants wait for the finished product. Again thank you. Hendrika

  9. says

    Hi Jami, thanks for the great tips. Drying and canning right after posting this!

    I was wondering if you use the olive oil out of the jars the tomatoes were stored in? The one comment with the U.C. Davis tips said the oil can go rancid and was wondering if that’s been your experience.

    • says

      I always use it and have never had it go rancid – but to be honest, I don’t know what that is like, since I’ve never had stored oil that I didn’t feel we could eat. Does rancid oil have a smell or something? How do you know it’s gone rancid? I’ve been cooking for 30 years and never experienced it! :)

  10. Robyn Carey Allgeyer says

    Jami, I already have a bag full of dried tomatoes that are more dried than you describe here. Can I still pack them in oil? Or, should I follow the directions provided by Anonymous, and let them soak in a vinegar solution until they soften a bit? Thanks so much for you reply!

    • says

      You can try the vinegar soak with a few and see what happens – I haven’t tried that. My experience with crisp tomatoes is that they never soften if just added to the oil. Let us know if the vinegar soak works! :)

  11. says

    I just found you on Pinterest. I’ve have been canning for about a year and love the recipe for the sun-dried tomatoes. Lucky me, I have an entire counter of Roma tomatoes needing put up. I am using half for the sun-dried tomatoes and the other half for tomato powder. Thanks so much for sharing~

  12. Lucy says

    Jamie – you indicated that you don’t use the “canning jar lids” but the vintage metal ones. In your opinion, are the canning jar lids still ok to use? That’s all if have.

  13. Charity K. says

    Hi Jami. I am a little late to this feed, but I hope this question finds you. This is my first time with trying the DIY sun-dried tomatoes packed in oil. My question is what do you think about baby food jars? I kept a lot from when my daughter was younger and wanted to use them for this method.

  14. Charity K. says

    Also, I am going to use my car for the drying method. I have read to put them out in the car in the hot sun, early in the morning until evening. They said this method could take 2 maybe 3 days. My question is do you think I should store them in the fridge when I bring them in at night during the drying process or leave them covered on the counter until the next morning when I put them out again? Thanks!

    • says

      That should be interesting! I would leave them out on the counter to keep air drying – the fridge may introduce moisture.

  15. Sue says

    Hi..i have been buying a store packed sun driied tomato and it is jam packed with garlic herbs and capers which worries me now……..i was going to replicate the mix until I read this site…wonder what process they do to get away with this? The toms are not even fully dried….i am not wanting my family to get sick? We are inAustralia and the jar is sold in a major chain store.

    • says

      The process can’t be replicated at home, unfortunately Sue, and be considered safe. I don’t know the process, I just know it involves machines, thermometers and stuff like that. 😉

  16. Matt says

    I put up four small bottle of dried tomatoes in olive oil, as described. I’ve done this for years, except did not vinegar wash them until I read this. I also put them in the fridge. First time ever, one bottle is fermenting! It’s in the fridge and it’s giving off bubbles. I’ve watched in a while and it truly is fermenting.

    It doesn’t smell bad at all so my guess is that this is just lactobacillus, and it’s probably perfectly ok. It actually might even be really good! However, I have no intent to find out. They are going in the garbage. Heartbreaking.

    I think the lesson is that despite all your work, sometimes things fail. Just get over it and learn. I think I will be more particular about which tomatoes I use and step up the washing and rinsing.

    • says

      Wow, thanks for that info, Matt! I’ve never had that happen in all the years I’ve been putting them up (but I do religiously dip in vinegar) – but you’re so right about fails – I had a jar of pickles turn slimy last year and all the others around them were fine. You just never know, so I’m always diligent to look and make sure they’re okay. And I’m with you – I would not want to find out about those tomatoes, either. 😉

    • says

      No, but it’s not really the seeds that are the issue, it’s the liquid surrounding them. It makes the drying process longer, so just beware of that. :)


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