Why does washing knives in the dishwasher dull them?

Question

Why does washing knives in the dishwasher dull them?

In: 890

Answer 1

Rule of thumb: put all varieties of cheap knives in the dishwasher, then sharpen or replace them as needed.

Keep expensive knives out because:

1) The heat and corrosive chemicals in dishwasher detergent are hard on all surfaces, including handles.

2) The inevitable jostling the edge will take against hard surfaces, dulling it.

3) There is no perfect steel. All steel carries with it trade-offs in the form of corrosion resistance, ease of sharpening, edge retention and toughness. The more expensive the kitchen knife, the higher the likelihood that some corrosion resistance was given up in exchange for increases in the other categories. That means chemicals (and sometimes even leaving them to air dry) will impact the performance of a fine edge.