So I was heating up some canned soup over the stove, and it felt a bit thin. So I thought to use some corn starch to thicken it up.

After pouring some in, some of it landed on my hand and I licked it off before I realized "Oh crap you probably aren't supposed to eat this raw".

Furthermore I didn't "boil" my soup after putting the starch in, more of a medium simmer-ish for a few minutes after putting it in.

I know raw flour is very bad because of bacteria/etc....but does the same apply to corn starch?

2 Answers 2


While it is never a good idea to make raw flours part of your diet or base a dish on them, eating raw starch is not so risky that you need to be worried about licking up a half-teaspoon of it. While overall figures are not available for corn starch, less than 3% of wheat flour in the US carries some kind of pathogen, and the percentage of contaminated corn starch can be assumed to be lower because corn starch is more heavily processed. Further, your body is adapted by thousands of years of evolution to dealing with minor amounts of food pathogens.

So, unless you are immunocompromised or someone in your family is, the raw/undercooked corn starch is less of a risk than many other things you eat and drink.

The bigger culinary issue is that, if you did not bring your soup to a boil, you did not fully activate the corn starch as a thickener.

  • I think I'm missing something in the first article. Where does the "less than 3%" number come from? I mean, the numbers I see are quite a bit lower than that, so while true it seems oddly specific in that case. Commented May 14 at 5:39
  • 1
    Ah, some of the figures in that article have been changed since I originally linked to it. Originally, the % of contamination added up to around 2.1% total. Now I could say "less than 2%".
    – FuzzyChef
    Commented May 14 at 17:50

The general advice is not to eat raw cornstarch due to potential bacterial contamination, and possible negative health effects. Health implications are off topic on our site, so let's just leave it at there being a potential for bacterial infection, as you point out, like flour.

I think a "medium" simmer for a few minutes probably takes care of any concern.

  • In a very brief Google search and Wikipedia, I have not been able to find an authoritative source that claims there is any danger from bacteria or causing other health issues.
    – Rob
    Commented Feb 10, 2022 at 2:16

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