The way knife makers talk about their knives you would think they were forged by magical elves in underground laboratories protected like Fort Knox. There is a lot of secrecy regarding the exact technique and formulation of their blades, but the specifics aren’t of too great importance when going to buy a knife (although learning even more won’t hurt you if you’re interested in such things).
A simple understanding of traditional materials and personal taste will usually be enough to guide you through the purchasing process:
Steel knives are an alloy of iron mixed with carbon. Most manufacturers use a few other elements, like nickel, silicon, manganese, and tungsten, that they typically keep under lock and key, like a secret recipe. There are different grades of steel, and the quality of the knife blade is dependent upon the grade, how it was forged (or, in some cases, cast), and how its edge was initially established. The less treated blades are more likely to rust (change back into iron oxide) and stain. Steel manufacturing has advanced a great deal in the past 20 years, so modern steel knives are less likely to rust than older ones. Steel knife blades can warp and their edges can dull quite easily (compared to other knife blade materials). However, they don’t break (like ceramic blades can) and are very flexible, which is great for some types of knives (like boning knives).
Stainless steel knives are iron and chromium (an element that reduces the incidence of the blade rusting). If shopping for stainless steel knife blades, look for a martensitic stainless steel because that means there is also carbon in the blade that increases strength.
Carbon-steel knives are a more accurate name for steel knives.
High carbon stainless steel
High carbon stainless steel is a type of stainless steel knife, but with more carbon than a standard steel blade. The benefits of a high carbon stainless steel are that these knives don’t rust like steel blades and they retain their sharpness longer than stainless steel blades. They tend to be more brittle than their metal peers, but they don’t typically break or chip like ceramic blades can.
Ceramic knives are usually made of an engineered zirconia ceramic, a substance more than four times stronger than stainless steel. As a result, they stay sharp significantly longer than all other blades and tend to cost more than their peers. Ceramic blades also don’t react with foods the way metal knives might. However, they cannot be washed in the dishwasher, as the mechanical washing process is likely to chip the knife or cause it to become more brittle. The blades do not bend and you can snap them if pressure is applied across the blade. They are very well suited for cutting fibrous vegetables that quickly dull other knives.
So what should I buy?
I can’t tell you which knives to buy because they really come down to personal preferences. I like a high carbon stainless steel knife for my 10″ chef’s knife and a ceramic knife to use on vegetables. I have a carbon-steel carving knife that I inherited from my grandfather that I love, but will probably replace it with a high carbon stainless steel one if I ever damage it.
Try out different types of knives in your friends’ kitchens to see what you like before buying. Also, I recommend buying knives online because you can usually get a better price than you might at a place like Williams-Sonoma. Also, check out restaurant supply stores and shops in New York’s Chinatown for good deals.