When chefs sharpen a knife before cutting into veggies and meat, shouldn’t we be concerned of eating microscopic metal shaving residue from the sharpening process?


I always watch cooking shows where the chefs sharpen the knives and then immediately go to cutting the vegetables or meat without first rinsing/washing the knife. Wouldn’t microscopic metal shavings be everywhere and get on the food and eventually be eaten?

In: 5225

*Kind of.*

What’s happening on a microscopic level is that all knife blades are sort of serrated, even if on a human-eye level they look like a flat blade. “dull” knives have those microscope teeth *bent* out of line from each other. So when a chef uses a steel (that rough metal tube thing they rub against the knife blade) they aren’t *removing* those microscopic bent teeth, they are bending them back into a straight line. So long story short, the chefs aren’t making as much as you think they are.

Secondly, sure, they are kind of making some metal dust, it’s not horrible for you to each some metal dust and certainly not large enough to, like, cut you up inside or anything like that.

You’d be surprised how much sand and dirt and crushed rock you eat in a year.

It’s not really possible to eliminate the finest particulates that simply exist outside or are generated during cutting and grinding, and it makes it into our food.

In the age of stone-ground flours this was pretty significant and actually wore teeth down over the years. It’s not as bad today.

Your digestive system is prepared for some indigestible grit to pass through along with the food, it’s unavoidable.

They are *honing* the knife, not sharpening it. Honing simply straightens out the blade but should not remove any material.

We should make a distinction between *honing* and *sharpening*

Honing a blade means that the knife edge has curled or bent slightly. This can easily be fixed, typically by giving a blade a few passes on a honing rod to bend it back into shape. Honing generally doesn’t remove metal from the blade.

Sharpening a blade means the knife edge is actually gone, and you will need to regrind an edge into the metal. This is done on whetstones or specific kinds of sanders. This does remove tiny bits of metal, and takes a fair bit of time to properly form the edge.

Typically on cooking shows you see people honing their blade (again, because no one is going to spend like 20 minutes doing a proper sharpening job), so there’s no (or very miniscule) contamination of the food.

Honing a knife would **not** be be expected to cause much metal to be liberated, but even if it did, **the metal would be harmless**.

“Fortified with iron” breakfast cereal literally puts tiny iron filings in the cereal. Literal specks of the metal iron. This is a commonly shown in school experiment meant for 6th graders.

If the acid in your stomach breaks it down, you’d absorb the iron content. if it didn’t, the metal dust would pass through you.