PATINA
Rust and stains occur naturally on high carbon steel blades. Carbon steels are reactive, and different carbon steels have different reaction rates. For example, even stainless steel will rust if left in extreme conditions. When caring for a carbon steel knife, the reaction is controlled in such a way that a protective patina develops and protects the steel. If desired, the patina can easily be removed to reveal the clear steel using abrasive kitchen cleaning equipment such as the sponges used to clean stove- tops. Rub length-ways while the opposing side of the blade rests safely on a flat surface.
Rusting may simply be avoided by keeping your carbon steel blades dry. With kitchen knives, a quick cold rinse under the tap followed by drying is enough. A patina will develop over the polished surfaces which with time will create a protective coating. A trait generally desired by carbon steel enthusiasts. Rust or patina can be washed off using universal stone. The same is applicable for hunting knives, especially highly polished carbon steel. The same instructions do apply to the coated Buckthorn series or UkkoPekka series knives, but with less worry. As the blade itself won’t rust but the edge itself, may. A strop does the trick well. Learning the characteristics of carbon steel knives is a charming and timely process.