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Oct 18, 2007 03:11 PM

Infused Oils....DANGER! Will Robinson!

OK Hounds, just think of the robot warning Will about the DANGER in Lost in Space**.
I am concerned that I have no robot to warn me about making infused oils.

Please tell me your food science, tips, techniques for infusing oils with:
1. garlic
2. basil
3. any leafy herb
4. seeds like cumin, fenugreek, cardamom
5. woody herbs like rosemary
6. your favorite

Best type of oil to use? Strain or not strain? Fridge or no fridge? Sterilize bottle or no (OK even I know that one).

A couple of other threads on infused oils seemed to peter out with unanswered queries.

Thanks! (no evil Dr. Smith need apply)

** For all you Gen-X'ers:

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  1. I think you need to avoid moisture, which could lead to spoilage - don't squeeze your garlic, in other words, but put peeled cloves in whole and let the oil dissolve the volatile flavors. Any dried or woody herb is a good candidate, and again don't crush any green leaves. The only infused oil I make regularly is chile oil, using olive oil (any, really) as the base. I tend to flounder around and try different combinations - crushed dried red peppers, chipotles, pasillas, arbol. I have a bag of dried pepper strands, like pepper hair, I got from Surfas in Culver City, and I chop and pound some of those. I put everything into a pint jar - just washed well and dried, really - and top up the oil and close it, and put it in a cool, dark corner of the kitchen counter. Then, every day or so, I turn it over, give it a good shake, and after a week start using the oil, replenishing as I go, until the flavor starts going flat.

    People have been doing this since long before either sterilization or refrigeration. Oil is a pretty good preservative, again as long as you keep loose moisture out. If I had any kind of fruit or high-moisture vegetable in there, I would certainly refrigerate it.

    1 Reply
    1. re: Will Owen

      CAREFUL many years ago before I knew better I made decorative oil boyttles for the window sill of my restautrant with whole garlic. After just a few days they exploded. THank God it was Tuesday , ( we were closed tues)

      I would give your technique a once over

    2. Anything that comes from the ground (garlic!) left in oil has a potential risk for botulism. You should boil the garlic in the oil for a minute before doing whatever you do with it. Also acidify the mix if you can and store it in the frig for safety. Never store it at room temp, as room temp combined with zero oxygen is exactly what botulism wants.

      Any other infusions that you make should definitely be refrigerated.

      5 Replies
      1. re: NeNePie

        My understanding is that for infused garlic oil one must acidulate the garlic -- boil it in vinegar for a few minutes. Pierce each clove several times with the point of a knife to allow the vinegar to get into the inside of the clove. But don't take my word for it -- do some careful research on making infused oils, preferably from a scientific/food chemistry source.

          1. re: alkapal

            Alton Brown, the host of "Good Eats," on the Food Network, did a show (or a part of a show--I can't remember which) on infusing oils. He was quite enthusiastic about it, with one exception: garlic. He recommended just buying commercial oil infused with garlic because he said that homemade garlic infused oil was notorious to containing botulism. There was no explanation given as to why garlic was so much more dangerous than other spices, herbs, etc. It was just a throwaway comment, before he proceeded to show the viewers how to infuse oil. So NeNePie's October 19, 2007 comment seems reasonable.

            1. re: gfr1111

              Anything fresh that has come into contact with soil is a potential botulism threat in an anerobic environment like oil.

              My guess is that since garlic grows in the soil itself it's a more likely issue.

        1. re: NeNePie

          I have been advised this (by Nancy Oakes) about root vegetables of any kind, use them for the vinegar not the oil.

          1. A book that you might want to take a look at down the line is Essential Flavors by Leslie Brenner and Katharine Kinsolving. It gives lots of ideas for infused oils and vinegars, and then recipes for using them. For the infused oils, it includes recipes for making oil with thyme, basil, mint, tarragon, rosemary, chives, orange, pink peppercorns, lemon, curry, cumin, ginger, shallots and roasted garlic.

            It does include the roasted garlic. I wonder if they get around the botulism possibility by roasting the garlic first.

            The book is probably out of print but used copies should be easy to track down.

            1 Reply
            1. re: karykat

              Thanks for the tip, alibris has several.

            2. A friend gave me two large bottles of olive oil for Christmas. I immediately put them in the fridge because I was not going to get to them for awhile and I did not want the oil to go rancid. One is infused with garlic and the other with rosemary. I learned a few weeks back that leaving garlic in olive oil can be very dangerous so I am afraid to use either of these oils now and yet I have resisted dumping them both out.

              I understand the olive oil containing the garlic may contain botchulism. Is there any way to test for this? Can I do anything to make this a safe oil again? Is the roesmary oil also growing botchulism or soemthing else harmful?

              I know I should just toss them both, but she bought very expensive oil and I would really like to use it if it's at all possible to ensure its safety.


              4 Replies
              1. re: CherylS

                Botulin toxin is the problem, so there is no way you can make contaminated oils safe again. As to the ones you have, I can't tell you. If the oil had been heated sufficiently in preparing the infusion to kill the bacteria before they could breed, you'd be fine. Otherwise, you couldn't pay me to use the stuff. Botulism is scary. Think systemic botox treatment -- like not being able to move your eyebrows isn't enough.

                1. re: Whippet

                  Thanks Whippet. The oil is going down the drain. So sad.

                  1. re: Whippet

                    Hi. Regarding your comment about heating the oil. I was wondering if it is possible to "cook" olive oil with different things (raspberries & basil--just one idea) then to strain if and bottle it. If it is hot and cooks in the flavors, will it still have the bacteria since it has been strained?? I hope this isn't a stupid question....I just think the possibilities are endless....BUT I want to make sure what I am making is safe! THanks!

                    1. re: laura84liz02

                      You cannot strain out bacteria. Seriously. You can't.