Carbon Steel vs Stainless Steel Japanese Knives

The trade-off

Stainless steel contains enough chromium to resist rust and staining. Carbon steel does not, so it rusts if left wet and turns grey or blue as a patina forms. A patina is a stable discoloration; rust is red or orange and eats into the steel and must be removed.

Many cooks find traditional Japanese carbon steels such as Shirogami and Aogami easy to sharpen to a very keen edge. Modern stainless steels such as VG-10, SG2 and Ginsan can also take a very keen edge, so stainless is no longer the automatic compromise it once was. How a given knife performs depends on its heat treatment and grind as well as the steel name.

The middle options

• Stainless-clad carbon: a carbon-steel core forms the edge, with stainless sides over most of the blade. The faces resist rust and staining; the exposed edge of the core can still rust if left wet.
• Semi-stainless: steels with a moderate amount of chromium. They resist rust better than carbon steel but less than stainless, and can still stain.

Which to pick

• First Japanese knife, shared kitchen, or you sometimes leave a knife on the counter: stainless.
• You already look after tools and want to learn sharpening: carbon steel or a clad carbon knife.
• In every case the care that matters most is the same: dry the knife, and keep it off bones and hard food.