According to Lee Leonard, author of "The Complete Guide to Sharpening," all steel contains carbon, but in high-carbon steel, carbon can account for as much as 1.2 percent of its contents. Low-carbon steels have as little as 0.06 percent carbon content.
Advantages of High-Carbon Blades
Chad Ward writes in "An Edge in the Kitchen" that high-carbon steel kitchen knives are harder, stronger and easier to sharpen than their stainless steel counterparts. Though high-carbon steel eventually develops a patina that some people dislike, the knife will still be food-safe. "Carbon steel . . . makes for a knife that can be tweaked to astonishing performance levels," Ward writes. "Professional sushi chefs rarely use anything else."
Disadvantages of High-Carbon Blades
High-carbon steel blades do have drawbacks. You have to wash them carefully and dry them thoroughly, or they will rust, and they may also affect the taste of the food you cut with them.
Advantages of Stainless Steel Blades
Stainless steel resists corrosion from contact with acid, and it will not rust. Ward also says that it holds an edge longer than high-carbon steel.
Disadvantages of Stainless Steel Blades
Stainless steel isn't as hard or as strong as high-carbon steel. It is more difficult to sharpen, and no matter how carefully you sharpen it, it won't achieve what Ward calls the "screaming edge" that high-carbon steel will.
How to Choose
If you want a knife that you can sharpen to a decent cutting edge and you don't have to fuss over, a stainless steel knife will work just fine. If you want a knife that will shave the fuzz off a peach and cut through anything you're likely to encounter, a high-carbon steel blade will suit you better.