I didn’t want to hijack the other knife thread, but a few people mentioned the old saw about not putting a good chef’s knife in the dishwasher. I’ve heard Alton Brown say this too.
Can someone explain (in as much detail as possible) the harm?
It strikes me as a classic myth, and I’ve never noticed any empirical problem myself (although I do sharpen frequently).
It’s hard to imagine that the alternative methods of sanitizing (I think bleach-water is common in commercial kitchens) would be less damaging than steam, hot water & dishwasher soap.
Mostly because the blades can rub up against other objects in the dishwasher and become nicked and/or dulled.
Not to mention nicking the rubber coating on the dishwasher rack.
Also, if the blade is stainless, the chemicals in the detergents can damage the finish, as well as washing it with copper.
The rattling around of the knife against other things in the dishwasher can cause nicks in the blade.
If you have a wood-handled knife, the constant wetting/drying of the wood will cause the wood to dry out, crack, and/or shrink, making the knife fall apart.
If I stuck my knives in the dishwasher, they’d rust. They aren’t stainless.
Plus, what they said. They don’t need to be rattling around against other objects. Nor do the other objects particularly benefit by being cut to ribbons by having my knife blades bounce off them in the freaking dishwasher.
Dishwasher detergent contains silica-based abrasives to aid the cleaning process through a “sand blasting” action. Great for removing dried-on food. The fine edge of a knife is blunted by this same action.
Don’t know about magnetism dulling blades, but carbon steel (non-stainless) blades will gradually dull just sitting in a drawer or knife block due to microcorrosion of the edge itself. This, rather than avoiding discoloration, is the real reason to oil such blades before putting them away. Carbon steel sports knives should not be stored in leather sheaths for the same reason; acids in the leather will corrode the edge in fairly short order and discolor the blade. It’s a bit less of a problem with stainless sporting knives, but still happens.
