Most everyone, by now, knows that food safety experts say you should avoid raw cookie dough or cake batter, because of the possibility of food poisoning. The two culprits in those foods are raw flour and raw eggs.
Studies have shown that both of those ingredients can and have been contaminated with pathogens. Flour can be contaminated with E. coli and Salmonella bacteria (an E. coli outbreak that is happening right now is linked to flour) and raw eggs can be contaminated with Salmonella. But are these foods contaminated often enough to be a problem?
The answer is yes, even though only a small percentage of raw flour and raw eggs may be contaminated.
These pathogens have what scientists call “low infective doses,” which means that just a few bacteria can make you very sick. The infective dose for Shiga toxin-producing E. coli, for instance, is just ten bacteria. And our food processing and distribution system complicates matters. One batch of wheat from one part of a field can, through processing, contaminate a large amount of flour that is then shipped to stores all around the country.
Eggs are problematic too. Salmonella bacteria have been found in a hen’s ovaries, which means that the pathogen will be inside the egg. No amount of washing is going to make that egg safe. Unless it is cooked to a safe final internal temperature, bacteria will survive and people who eat those eggs will get sick. Your breakfast egg cooked “over easy” can be dangerous.
Another issue is age. Let’s face it, raw cookie dough is irresistible to little kids. And unfortunately, the younger the child, the more likely they will become seriously ill or develop life-threatening complications if they contract an E. coli or Salmonella infection. Hemolytic uremic syndrome, the complication that can develop from a Shiga toxin-producing E. coli infection that can destroy the kidneys, is most likely to develop in children under the age of five.
But take heart. There are ways to make raw cookie dough safer, although there’s no guarantee that no bacteria will be present in the dough. You can buy pasteurized eggs (follow those expiration dates to the letter). And you can pasteurize flour yourself at home; there are many online sources to help you do that. Perhaps some corporation will offer pasteurized flour in the future.
And remember, warm baked cookies taste even better than raw cookie dough.
