Oh Dear, should I worry?

I like flavor infused oil -

So I gather a few cloves of garlic, crush them with a knife and slice them. Then I take a container, put in the garlic, a generously large pinch of "Italian Seasoning", cracked pepper, red peper flakes and then pour in the olive oil.

I put this in the fridge and let it macerate....... er steep. A lot of times I'll just add more ingredients rather than starting with a fresh batch. I keep it stored in the fridge using and adding as needed, sometimes for a couple of weeks before I make a new batch.

I then use this oil for cooking and dipping. Before I use it for cooking I stir up everything and then add the oil with the suspended herbs and some sliced garlic. When I use it for dipping, I generally just spoon out some of the oil without stirring things up.

So in most instances my flavor infused oil gets heated when I use it for frying or roasting. However sometimes there is no heat applied when it gets used as a dipping oil.

In light of the discussion about botulism in the "Do You Make Your Own Hot Sauce" thread - it seems like what I am doing might not be a very safe practice. I kinda get the impression that I should:

A. Not keep this for more than a week.
B. Not use it for dipping.

- or-

C. Change my method. Maybe I should heat the oil almost to smoke point, then remove the oil from the heat source and add the garlic. After that has cooled then I could add in the herbs and spices.

What think you all?

Thanks for any response.

Hmmm. First guess on my part would be that you're ok as you get a lot of air into the container when you open it up and use it. If you have oxygen getting in, you should be good as far as botulism goes, anyway.

I'm no bacteriologist, though!

Thanks for asking the question, M R ! This is something I'd love to know too, because infused oils were such a popular thing a few years back, and we got right into it. Chilli oil, garlic oil, the whole bit. Now I'm also wondering if it's safe ?

Someone here will know, this is always the best place to ask just about any question, I've found..



Celia

In light of the discussion about botulism in the "Do You Make Your Own Hot Sauce" thread - it seems like what I am doing might not be a very safe practice. I kinda get the impression that I should:

A. Not keep this for more than a week.
B. Not use it for dipping.

- or-

C. Change my method. Maybe I should heat the oil almost to smoke point, then remove the oil from the heat source and add the garlic. After that has cooled then I could add in the herbs and spices.

What you're doing is time-honored tradition, but the FDA has advised people to refrigerate garlic-in-oil mixtures and they require commercial versions to be acidified to prevent the growth of C. botulinum, the causative agent of botulism. Here's a link to the actual advisory: http://www.fda.gov/bbs/topics/ANSWERS/ANS00523.html

To be absoultely safe, you should probably get rid of any previously prepared oil, make some new stuff and put it in the fridge.

Mark Lipton

This is indeed a matter for concern.

Heating the oil to the smoking point before adding the garlic won't help. It's the garlic that is the worry, not the oil.

If you roast the garlic before doing the preparation, probably no worries.

If you're doing an infusion of raw garlic in oil, there's cause for concern. You want to make sure there's enough air captured in the mix, and that it's kept at low enough temperature, that C. botulinum won't be able to grow.

This is almost never a problem for salad dressings, as there's usually vinegar in the infusion (contributes the necessary acidity to prevent the bacteria from growing) or you shake the infusion often, thus aerating it.

But if it were me, I wouldn't store whole garlic cloves immersed in oil. Vinegar (acid) or alcohol (allows oxygen contact, and also mildly acidic), yes, but not oil.

-Paul W.

Given Mark and Paul's advice, I think I'll be giving the whole garlic in oil thing a miss from now on. But would crushed or sliced or finely chopped garlic be any safer ? Also, M R, one thing I would avoid is topping up old stuff. I think starting a new smaller batch weekly is sounding like a good idea.

Can someone please also clarify, just so I understand, what does refrigeration do to the botulism spores and toxins ? If they're actually IN the whole garlic, how does refrigeration stop you getting sick ?

Thanks, Celia

Thanks for the information, some comments were revolving around the supposition that I was using whole garlic. I am pretty sure I mentioned that I crush the garlic and then chop it.

At this point I think I'll stop the feed and bleed procedure and mix a new batch every couple of weeks or so or maybe every week. Generally, when I use this infused oil, it is for cooking, either on the stove top or in a HOT oven (375 to 425 F).

I've been doing this for a while, so I am either healthy or lucky..........

Mike, that's a great webpage you have ! So nice to have you posting here !

I suspect the jury might be out a bit on whether chopped or sliced raw garlic is much safer than whole, and Mark and Paul's advice was weighted towards caution. Growing up in a Chinese household, semi-cooked chopped garlic in oil was always a staple, but from memory it was always turned over pretty quickly.

Cheers, Celia

Given Mark and Paul's advice, I think I'll be giving the whole garlic in oil thing a miss from now on. But would crushed or sliced or finely chopped garlic be any safer ? Also, M R, one thing I would avoid is topping up old stuff. I think starting a new smaller batch weekly is sounding like a good idea.

Can someone please also clarify, just so I understand, what does refrigeration do to the botulism spores and toxins ? If they're actually IN the whole garlic, how does refrigeration stop you getting sick ?

Thanks, Celia

Refrigeration greatly slows down the growth of bacteria. It may also prevent activation of the spores. This is how a refrigerator preserves food and prevents it from spoiling. So refrigeration will definitely help.

Crushing, slicing, and especially finely chopping the garlic will greatly increase the surface area that is exposed to oxygen before it goes into the oil. That will help on the botulism front.

-Paul W.