How to Spot Insect Infestation in Dried Beans with Pictures

Infested kidney beans with small insect holes in peelA few days ago, I wrote about the reasons that beans may not get hard after cooking. Today I’ll address a different issue that also relates to beans that may have not been stored carefully: infestation. To avoid problems of infestation of grains and legumes, first follow the suggestions in my earlier post on how to prevent insect infestation.

I generally prepare beans in bulk, especially types that take a long time to cook.  The other day, after soaking a kilogram of dried kidney beans, I noticed many suspicious-looking holes. Holes are a sign that insects have invaded and may have taken up residence in your food. I’m pretty sure I would have noticed the holes before soaking, had I looked carefully, but soaking enabled me to take them apart and look inside. I am sharing the pictures with you, of course. If the idea makes you queasy, I suggest you stop reading now.

With light-colored beans, like navy beans, you can actually see the insect residing under the skin if the beans have been soaked.

After soaking I picked up small handfuls, lay the beans out on my palm, looked for blemishes, and flipped them over on to the other hand to view the second side. I didn’t open them up right away, to save time. I found 20 or so infested beans in the package. In the end I only needed to open a few samples to see that most  were not worth salvaging. In  a few cases, the infestation only went a couple of millimeters deep.

Below you can see a bean with one hole, and how it looked inside:

Here is another bean, with two insect holes:

Despite this being the worst case of infestation I’ve seen in a long time, most of the beans were fine and tasty. They did take a long time to cook, though.


  1. http://Ilana says

    Thanks, you said that you soaked 1 kg of beans. Assuming you didn’t use them all at once, how do you keep them? Freezer?

  2. http://Stephanie says

    But you didn’t say what insect this is, and if they are dangerous. My beans are infested, not all of them and I would like to know if I should throw all of them away. And I would appreciate if you could add the name of this insect. Thanks.

    • I don’t know what insect it is. I keep kosher, and insects are not kosher. I did cook and eat the ones with no signs of infestation.

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