Let's break down the difference between carbon and stainless steel to aid in choosing the right knife for your needs. Understand that one is not inherently better than the other. They each have their own unique qualities that the other does not possess.
All steel starts with iron. Fe on the periodic table. Iron is fairly soft and pliable, especially when heat is applied. Oh, and it rusts like crazy when exposed to air and moisture. Since the early Roman era, metallurgists have been experimenting and producing novel steels by adding other elements like carbon to the base iron. The addition of carbon was a massive technological breakthrough at the time because carbon is the main element that makes iron hard.
Around the 1st century BCE carbon steel was born.
Carbon steels typically have .50% to 2% carbon added. Carbon steels like 1095, 01, W2, and 52100 are commonly used in knife making today, especially with those that forge blades.
These modern carbon steels have more than just iron and carbon in the recipe, and include various small quantities of other elements such as magnesium, chromium, tungsten, and vanadium. Carbon steels are easy to forge, and often can be heat treated sufficiently with the less precise temperatures of coal and propane forges.
Carbon steel is lovingly referred to as a "living steel" due to its high chemical reactivity to the environment. Rust, patina, and various other effects occur from the steel's daily use. For a knife, this means potentially beautiful textures, patterns, and colors from the forging and/or etching process, as well as patina patterns from the chemical reactions to acid foods. Thus, there is a need to take extra care with the knife to avoid rusting or unwanted discolorations.
Stainless steel is very much like carbon steel, but includes other elements or higher quantities of certain elements that render the steel "stainless". The first stainless steel wasn't invented until the 1900's. A chromium content of 10.5% is the minimum for stainless steel, however more like 11.5% is needed for practical rust protection. For example, the popular knife steel AEB-L has around 13.5% chromium and 1% carbon. Now, even with 15% chromium a stainless steel knife can rust. It just takes a long time or exposure to very adverse conditions.
The anti-rust factor of stainless makes its ease of use superior to carbon steel, however it doesn't take forging well, nor color/texture variation from forging, heat-treating, and etching. So often stainless steel knives are stuck with shiny blade finishes. However, some stainless steels can be etched and tumbled for a darker patterned blade, or bead blasted to render a matte gray finish.
(Photo: Two Boning knives made from AEB-L stainless steel. The one on the left was bead-blasted, and the other hand-buffed).
So, which one? It's up to you. The main two factors (all else being equal) is the look of the blade and the ease of care. You can get some interesting textures and patterns from carbon steel that you can't from stainless, but you have to take extra care of carbon steel. In a kitchen context this means not letting the carbon steel knife stay wet for too long or it can develop rust. A carbon steel knife will also quickly tarnish (black stains) when in contact with acidic foods like lemon and onion. Stainless blades will basically be unaffected by these things with normal use.
Redroot Blades produces kitchen knives and outdoor knives in both carbon steel and stainless steel. Check out both collections and see what blade finishes you prefer. Also, follow our instagram for lots more information about our products and releases.