Views / Citizen Scientist

What's E. coli doing in my cookie dough?

The bottom line: E. coli comes from poop.

How did E. coli bacteria end up in flour?- Holly, Toronto

As a cookie dough aficionado, I share your extreme concern.  

There are many subtypes of E. coli bacteria, most of which are perfectly friendly.

But not E. coli O121, the particularly gnarly type involved in the present recall of Robin Hood and Creative Baker flours and prepared tart shells from Harlan Bakeries. The bacteria makes a chemical called shiga toxin, which causes bloody diarrhea,  abdominal cramps and even kidney failure in some people.

The natural habitat of E.coli is the lower intestine of mammals. Yes, E. coli comes from poop. And somehow, it got into our flour. Not a nice thought. And how exactly this happened is still being investigated.

It’s possible for nasty strains of E. coli to pass from person to person, especially if proper hand hygiene isn’t followed. But the usual suspect in these types of situations is cow poop.

Past outbreaks have been blamed on wheat irrigated with water contaminated with cow manure. Combine that with poor sanitation and cross-contamination at a processing facility, and you have a recipe for disaster.

And E. coli O121 has been known to grow in grain mills and processing equipment, especially if the environment is humid. 

So what is a cookie dough lover to do?

First, check your cupboard. Quite a large number of products have been pulled from shelves (see the Canada Food Inspection Agency website for the full list). If you have any at home, toss ‘em.

But regardless of the brand, it’s not considered safe to eat food containing uncooked flour. But don’t go crying over your cookie dough just yet.

If you heat the flour to at least 160 C, it’s perfectly safe to eat. In fact, it’s recommended that you let the youngest member of your kitchen team lick the beaters. It’s practically a rule. 

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