# How can I infuse olive oil? **URL:** \ **Category:** Factual Questions\ **Created:** [June 26, 2002, 6:05pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073 "2002-06-26T18:05:24Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![zber](https://avatars.discourse-cdn.com/v4/letter/z/c5a1d2/32.png) [@zber](https://boards.straightdope.com/u/zber)\ **Post date:** [June 26, 2002, 6:05pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073/1 "2002-06-26T18:05:24Z")
I want to infuse olive oil with rosemary but every time I have tried a gross white mold-like substance forms on the rosemary within about three days. I pick the rosemary from the garden, wash it and then cover it with olive oil but it never takes. I have tried heating the olive oil with the rosemary in it but again within a couple of days I have the funk covering the rosemary stem. So - how can I do this so that it doesn’t get “funky”? Z ---
**Author:** ![JohnM](https://avatars.discourse-cdn.com/v4/letter/j/848f3c/32.png) [@JohnM](https://boards.straightdope.com/u/JohnM)\ **Post date:** [June 26, 2002, 6:19pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073/2 "2002-06-26T18:19:49Z")
I believe your problem is this (bolding mine): > [@](#): > > \*Originally posted by zber \* > > …I pick the rosemary from the garden, **wash** it and then cover it with olive oil but it never takes. If there is _any_ water on the surface of the rosemary (or garlic, or peppers, or whatever) that you are covering with oil, you can get the mold or discoloration that you are noticing. After you’ve picked and washed the rosemary, pat it dry as much as possible, and then give it a while to air dry before adding the oil. If it was really wet, I’d try a slow oven for a couple hours. Also, be sure the rosemary stays completely covered by oil as you begin to use it (just add more oil), or you can get the same problem. ---
**Author:** ![smoke](https://avatars.discourse-cdn.com/v4/letter/s/c5a1d2/32.png) [@smoke](https://boards.straightdope.com/u/smoke)\ **Post date:** [June 26, 2002, 6:51pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073/3 "2002-06-26T18:51:10Z")
[Epicurious.com](http://www.epicurious.com/) has a “recipe” for infusing olive oil with rosemary and mushrooms. [This](http://www.epicurious.com/run/recipe/view?id=4536) is the link, but unfortunately, it seems their database is down right now. Check the link later on. (BTW, epicurious has been a pretty good site for recipes and techniques, IMO, YMMV, dealer costs not included) -j ---
**Author:** ![zber](https://avatars.discourse-cdn.com/v4/letter/z/c5a1d2/32.png) [@zber](https://boards.straightdope.com/u/zber)\ **Post date:** [June 26, 2002, 7:24pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073/4 "2002-06-26T19:24:03Z")
Thanks. I followed Epicurious’s instructions before but failed to note the “Refrigerate up to 3 weeks”. Um, have I been concocting something more along the lines of botulism by not refrigerating oils? ---
**Author:** ![JohnM](https://avatars.discourse-cdn.com/v4/letter/j/848f3c/32.png) [@JohnM](https://boards.straightdope.com/u/JohnM)\ **Post date:** [June 26, 2002, 7:43pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073/5 "2002-06-26T19:43:01Z")
I never refrigerate olive oils, infused or otherwise. They start to solidify at refrigerator temperatures, which makes them a pain to use. I keep mine in a cupboard in the kitchen, and they last for months, with no noticeable outbreaks of botulism, e. coli, or other food-borne illnesses. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [June 26, 2002, 8:33pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073/6 "2002-06-26T20:33:05Z")
> [@](#): > > I pick the rosemary from the garden, wash it and then cover it with olive oil but it never takes. Are you drying the Rosemary, or at least crushing it thoroughly so that the oil can get into the leaves ? If not, there’ll be places with enough water present to support mold growth. Crushing, or cutting as with Pesto, will also speed up the infusion process for you. ---
**Author:** ![Eve](https://avatars.discourse-cdn.com/v4/letter/e/9e8a1a/32.png) [@Eve](https://boards.straightdope.com/u/Eve)\ **Post date:** [June 26, 2002, 8:39pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073/7 "2002-06-26T20:39:01Z")
. . . Now I have the unfortunate mental image of Popeye having a three-way . . . ---
**Author:** ![Khadaji](https://avatars.discourse-cdn.com/v4/letter/k/9e8a1a/32.png) [@Khadaji](https://boards.straightdope.com/u/Khadaji)\ **Post date:** [June 26, 2002, 8:43pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073/8 "2002-06-26T20:43:28Z")
> [@](#): > > \*Originally posted by Eve \* > \*\*. . . Now I have the unfortunate mental image of Popeye having a three-way . . . \*\* LOL. Well, I **didn’t** , but I do now… thanks a lot! ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [June 26, 2002, 9:18pm UTC](https://boards.straightdope.com/t/how-can-i-infuse-olive-oil/116073/9 "2002-06-26T21:18:48Z")
Sure enough, improproper infusion is a food safety concern: [Infused Oils- More Than Herbs in Those Bottles](http://www.uwex.edu/ces/flp/specialists/ingham/dec97.html) > [@](#): > > When preserving foods in oil, it is possible to set up an environment perfect for the germination and growth of C. botulinum spores: a non-acid, oxygen-free environment. Oils are thick, and parts of a bottle of infused oil can definitely be oxygen free. To be safe, commercially prepared infused oils must contain agents such as phosphoric acid or citric acid or some other agent to make the oil too acidic for bacteria to grow. This: [Oil Infusions and the Risk of Botulism](http://www.colostate.edu/Orgs/safefood/NEWSLTR/v2n4s08.html) says pretty much the same. This: [Safely making chile oil](http://www.ochef.com/272.htm) emphasizes the same problem when making chili oil. Dry ingredients are _important_. Can’t find a recipe that says how much citric acid is needed to solve the problem. It’s probably a lawyer-thing :mad: