Deadly Dressing?!?!

May 27, 2009 6:26 PM

Can I Eat It Filter: homemade salad dressing edition

In an effort to not eat so much HFCS, I bought a salad dressing mixer similar to this. The first time I used it, I put it in the fridge after mixing and, of course, the oil solidified. The next time, I just left it on the counter, but Mr. Arkham was concerned. The dressing only contained olive oil, soy sauce, rice vinegar, spices, and garlic. Think it's safe to keep out of the fridge? For how long? Will the garlic go bad? (I'm assuming any creamy dressings would need to be refrigerated, of course.)

And if commercial dressings are full of preservatives, why are they all "refrigerate after opening"?

posted by JoanArkham to food & drink (7 comments total)

The senses of touch, smell, sight and - if you're brave enough - taste, have ensured the survival of the human race until now. It's what they're for. Despite protestations otherwise.
posted by fire&wings at 6:32 PM on May 27

We keep our homemade salad dressing out of the fridge all year round. It's made with olive oil, balsamic vinegar, pepper, salt, honey, grey poupon. We have not died, and it's been 20 years or so. And my grandparents survived 60-70 years or more keeping their very similar dressing out of the fridge. (FYI, rub the salad bowl with a cut garlic clove before making your salad for better flavor.)
posted by chr1sb0y at 6:38 PM on May 27

All those ingredients are fine to store at room temperature separately, but there are a load of official warnings out there about storing garlic in oil at room temperature.

UC Davis:

BOTULISM WARNING:
Regardless of its flavor potency, garlic is a low-acid vegetable. The pH of a clove of garlic typically ranges from 5.3 to 6.3. As with all low-acid vegetables, garlic will support the growth and subsequent toxin production of the bacterium Clostridium botulinum when given the right conditions. These conditions include improper home canning and improper preparation and storage of fresh herb and garlic-in-oil mixtures. Moisture, room temperature, lack of oxygen, and low-acid conditions all favor the growth of Clostridium botulinum. When growing, this bacterium produces an extremely potent toxin that causes the illness botulism. If untreated, death can result within a few days of consuming the toxic food.

STORING GARLIC IN WINE OR VINEGAR:
Peeled cloves may be submerged in wine or vinegar and stored in the refrigerator. A dry white or red wine is suggested; white or wine vinegars also work well. The garlic/liquid should be kept for about 4 months in the refrigerator. Discard both the cloves and the liquid if there are signs of mold or yeast growth on the surface of the wine or vinegar. The garlic-flavored liquid and the garlic cloves may be used to flavor dishes. Do not store the garlic/liquid mixture at room temperature because it will rapidly develop mold growth.

STORING GARLIC IN OIL:
Extreme care must be taken when preparing flavored oils with garlic or when storing garlic in oil. Peeled garlic cloves may be submerged in oil and stored in the freezer for several months. Do not store garlic in oil at room temperature. Garlic-in-oil mixtures stored at room temperature provide perfect conditions for producing botulism toxin (low acidity, no free oxygen in the oil, and warm temperatures). The same hazard exists for roasted garlic stored in oil. At least three outbreaks of botulism associated with garlic-in-oil mixtures have been reported in North America.

FDA (1993): "FDA has been receiving inquiries about proper storage of homemade and commercially prepared chopped garlic-in-oil, garlic-in-butter and garlic-in-margarine mixes. FDA is warning consumers that such mixes, especially those prepared fresh at home, should be kept refrigerated. Left at room temperature, the mixes may cause potentially fatal botulism food poisoning."

There may be enough vinegar in your dressing to make it acidic enough to be safe, but I don't have the expertise to assure you of this.

It doesn't take long for solid olive oil to go liquid again, so you can refrigerate the mixed dressing for a few days and take it out maybe 30 minutes before you eat. Or mix up everything except garlic, leave it on the counter, then add fresh garlic to your salad after pouring the mixture. Or mix up everything except olive oil, leave it in the fridge, then add the room-temperature olive oil directly to your dish.

chr1sb0y's dressing is fine on the counter because it has no garlic in it.
posted by maudlin at 6:44 PM on May 27 [3 favorites has favorites]

The garlic is the only thing I would be concerned about. I would probably keep it out for, say... 2 days? But after that it would get heaved out. In the future, keep all those preservey ingredients premade in a cupboard and add fresh garlic to each batch or, as chr1sb0y suggested, rub in in the salad bowl. Good idea!
posted by nitor at 6:56 PM on May 27

The senses of touch, smell, sight and - if you're brave enough - taste, have ensured the survival of the human race until now.

Survival of the human race, yes; survival of individual humans, no.
(Without passing judgment one way or the other on this particular case.)
posted by DevilsAdvocate at 7:04 PM on May 27 [4 favorites has favorites]

Yeah, it's the garlic that's the problem. The vinegar should inhibit the growth of the bacteria that would be problematic if you had just garlic and olive oil, but I'd still be wary. It's not a big expense - on this one, I say throw out and start over.

I don't use bottled dressing - I make a new dressing each time we have salad, and it's very fast and easy and totally variable with no such worries. By mixing dressing in the empty bowl, then adding greens and tossing, you use less dressing but get full flavor, too. Just a thought to prevent any future anxieties.
posted by Miko at 7:26 PM on May 27

Thanks, all! I remember when they had to recall a bunch of that jarred garlic, that's the bit I was wondering about.

In the future, I'll just make less if I'm using garlic. I just need to get in the habit of making fresh instead of reaching for a bottle.
posted by JoanArkham at 8:38 AM on May 28