LONG time. Just
option would be
better than
I've not run a kitchen knife test, but I've noticed a few things between the good german stainless knives and carbon steel ones.
The carbon steel takes a really nice edge, and grinds really smooth. You can almost strop it to a mirror finish.
Stainless stuff is harder to polish and strop, it always has these ridges that are hard to remove. It just seems like it's a mix of hard and soft materials. This might make them seem like a saw once the blade is dull, so they still kind of cut through stuff. Crappy stainless knives are gummy and can't even be sharpened at all.
Even the german stainless knifes need a little touch up out of the box for some reason. I'm going to guess the japanese stuff like Global and Mac come fully and completely sharpened since they love their knives.
My daily carry knife is a Microtech made of "154-CM", and that's a weird material, some sort of knife foamer type alloy of who knows what. That stuff is hard and tough. I'd be interested to see a kitchen knife made of the stuff and how it holds up.
Didn't know about the onion. I don't hang out in a kitchen, but I also never let stuff dry up or set on a blade either, especially the pocket knife.