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Jun 30, 2011 10:38 AM

Sun Dried Tomatoes with Oil & Garlic – Botulism

I am having Sun dried tomatoes sitting in a bottle for months now and was thinking of making use of them now

I will be using - Olive oil, Fresh Basil Leaves and Garlic with my tomatoes.

1]Now, I am worried about Botulism. So what shall I do to avoid it? I am thinking of marinating them at least a month before consuming them, So shall I let them marinate In the refrigerator?

2] I am making small quantity and hence using air tight container is not possible, as where I live all air tights are big big bottles only. So, I decided to use a random glass bottle I have in my home (Non air tight). As I will be using this, shall I be worried abt anything ?

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  1. "
    Storing Garlic in Oil - Warning! - Not Safe.

    It's important to keep food safety in mind when storing garlic in oil. Low-acid foods like garlic can be a source of Clostridium botulinum bacteria which are found in soil, water, and air. Oil's oxygen-free environment is perfect for growth of this anaerobic bacteria. Garlic in oil, therefore, must be stored correctly to prevent botulism food poisoning.

    Commercial garlic-in-oil mixtures are acidified to prevent bacterial growth. These products can be stored safely at room temperature. Unfortunately, acidification of garlic in homemade oil mixtures can't be recommended because no research exists to support proper procedures. Different people recommend different methods and time to acidify and it is hard to know who is right. Instead, it's best to store these hazardous oils in the refrigerator, but for a limited time only. This conflicts with the desire for long term storage.

    When raw garlic is stored in oil, Clostridium botulinum bacteria can grow. These mixtures must be refrigerated to slow bacterial growth. After 3 weeks of refrigeration, the increased number of bacteria will become a food safety hazard. Therefore, these mixtures should not be refrigerated longer than 3 weeks.

    When garlic is immediately removed after flavoring oil, the bacteria will not have a "food source" for growth. The flavored oil can be stored safely at room temperature.

    When vegetables or herbs are dried, water will not be available for bacterial growth. Therefore, DRIED vegetables or dried herbs (including garlic) in oil can be stored safely at room temperature. Note. Tomatoes are high in acid. Therefore, plain dried tomatoes in oil can be safely stored at room temperature.

    Storage Recommendations: (According to Oregon State University Extension Service).

    Raw or cooked garlic and/or herbs in oil:

    These mixtures MUST be refrigerated. Do not store them longer than 3 weeks in the refrigerator. (Note. Raw garlic MAY be safely stored in vinegar at room temperature.)

    Dried garlic and/or herbs in oil: If oil is seasoned with dried garlic and/or dried herbs, the mixture may be safely stored at room temperature. (Refrigeration may delay rancidity, however.) "



    4 Replies
    1. re: C. Hamster

      C. Hamster has it exactly right. I have been food safety certified three times, and this question was always brought up in class. I don't chance it and would only make and use up small batches right away, within a couple days, or use a good store bought brand. Not worth the risk.

        1. re: C. Hamster

          You need to be careful with the tomatoes, as well; many varieties are not acidic enough to be safely packed in oil. (Thus the current advice from the government to add lemon juice to tomato sauce before canning.) Call your local county extension office for sound advice.

          1. re: C. Hamster

            Thanks, I was just thinking about this tonight. Lots of leftover chopped Garlic from the weekend that I was going to throw into the freezer covered in evoo...would this be ok, or even freezer no good? Thanks

          2. Well, i fully understood the above.... but then i was wondering how come many ppl make these tomatoes at home without facing any safety scare/problem ?

            1 Reply
            1. re: craige4u

              Dried Tomatoes are ok (see the article I quoted) it's the garlic and basil that are not. Particulalry the garlic as it grows in the ground.

            2. C. Hamster, thx for detailed info.

              Now, i will not use garlic at all in my tomotoes., but still i am planning to use fresh basil leaves... Now, plz inform wht kind of care i have to take in this case and does this cause harm too?

              Also, can i leave the prepared tomato with basil at room temps. ?

              PS: If there is still scare of gettin ill, i might go and buy store boughtSun dried tomatoes at extravagent prices !!

              2 Replies
              1. re: craige4u

                I just bought some at Costco, as yet untried. $8 for a two-pound glass jar (quite packed) of sun-dried packed in olive oil with garlic and herbs. Sulfites added, says to refrigerate after opening, keeping oil above level of tomatoes.

                1. re: craige4u

                  You should never add oil or any type of fat to anything that is to be canned. You can can foods as pickles, in plain water or in fat-free broth with the use of the proper equipment (Pressure Canner), but in no case should oil be added. You can can the tomatoes with the Basil (add about a teaspoon of lemon juice to each PINT) and process in a Pressure Canner. When you go to serve it, dress it with Olive Oil then, but do not add oil to the jar. BTW use DRIED basil, not fresh. When fresh basil is canned, it might lend a bitter taste.

                2. Anything that grows in the soil has a risk of botulism. It's found in water and soil. While you can cook out the toxin, it doesn't kill the spore, and so if the conditions are right again, it will produce more toxins.

                  Honestly, I would buy the prepared. It's one thing to can high sugar high acid foods, which are low risk, but I wouldn't mess around with the herbs and oil packed veg.

                  Here is more info on botulism toxin:


                  1 Reply
                  1. re: Matahari22

                    This is why you should only use a Pressure Canner to put up foods unless you are an expert canner. The Pressure canner gets far hotter than the boiling point of water, and it literally autoclaves the food, killing the botulism spores. Everything that is canned does not have to be in sugary sauces or vinegary brines. But for most applications where it is not jellied, candied or pickled, you MUST use a Pressure Canner.

                  2. This has all been very informative and is much appreciated! What about garlic that has been roasted in olive oil and lime juice? We made Rick Bayliss' Mojo de Ajo six months ago and still have some in the fridge. The recipe says "This mojo will keep for up to three months in the refrigerator as long as there's enough oil to keep the garlic covered." Do you think the lime juice made it "acidified" and therefore safe to eat after all this time?

                    4 Replies
                    1. re: goodeatsgal

                      Temperatures above about 250 are usually sufficient to kill c. botulinum if the garlic is fully brought up to that temperature and held there. Some browning throughout would indicate that the temperature has been sufficient. Generally speaking, highly acidic environments also prevent c. botulinum from producing its toxin. BUT the entire medium (food) has to be pretty acidic. Just a little bit of lime juice in a recipe made of otherwise problematic raw ingredients isn't gonna cut it.

                      The other thing people haven't mentioned is that you can effectively prevent the botulism toxin by freezing promptly when the recipe is made and quickly thawing before use. Also, bringing to boiling temperature or higher for about 10 minutes denatures the toxin, if you want to be extra safe.

                      1. re: cowboyardee

                        Agree. Freezing is an excellent way to preserve this type of food. For example, I made caramelized onions for French Onion Soup in advance and froze individual batches in air tight containers. Worked perfectly. But you must freeze promptly, don't allow the food to cool excessively or you will defeat your purpose.

                        1. re: brensgrrl

                          Don't understand this. I always cool, then chill food before freezing.

                          1. re: pikawicca

                            I think the key is to avoid having the food sit in the bad temperature range (ie, room temperature/body temperature) for too long.

                            I generally to cool stuff until it's not steaming before putting in the fridge, and not putting it in the freezer until it's fully refrigerated. Putting hot food directly in the freezer can result in overly mushy food or excessive ice crystals (all the steam will condense on the food) and tends to melt the other stuff in the freezer, not to mention over straining the motor.