Carbon steel knives are loved by many chefs for their ability to keep dangerously sharp edges with minimal sharpening, even after months of wear and tear. But carbon steel is to knives as cast iron is to skillets: It gets a bad rap for being difficult to maintain.
We'll admit: carbon steel requires more maintenance in the moment than stainless steel to prevent it from rusting. But the few extra steps required are well worth it. With carbon steel, you'll end up sharpening your knives a lot less, and using them more often (take, for example, Messermeister's Essential Carbon Steel Parer & Chef's Knife Set, available in the Shop). And the beautiful blue-grey patina that the blades will take on? Well, that's just a bonus.
Carbon steel is thought to maintain its sharpness better than stainless steel because of the grain of its metal. The finer the grain of the steel, the thinner and sharper its edge can be honed. Stainless steel contains chromium, which prevents the metal from rusting. The chromium combines with the carbon and creates large, brittle clumps in the otherwise fine grain of the metal. These clunky chromium carbides weaken the structure of the stainless steel, whereas the pure carbon steel's grain isn't compromised by chromium carbides.
Caring for a carbon steel knife is not as intimidating as it seems—in fact, the kind of maintenance required is really the kind of maintenance you should be giving to your good stainless steel knives, too. After all, your chef's knife is your most important tool in the kitchen. It should be treated right!
Break in your carbon steel knife by treating it with vinegar before the first time you use it. Rub the entire blade with a white vinegar-dampened paper towel and let the blade sit for 5 minutes. Rinse the vinegar off, dry the blade completely, and then repeat the entire process over two or three more times. The blade will start to show a blue-grayish color. This is the beginning of your patina. Patina is not rust—it actually acts as a barrier to slow oxidation. As you use your knife more and more, you'll see this patina developing and darkening over time. It's your knife's personal (beautiful) history.
Hone the edge of your knife before each use. Honing is different than sharpening: Just because a knife isn't cutting cleanly doesn't mean it isn't sharp. The sharp edge may just be out of alignment, or "rolled over." Realign the edge by anchoring the tip of a honing steel on a cutting board—think of the honing steel as a "sword in the stone"—and drawing the blade of your knife down the honing steel at a very slight angle, 10 times on each side.
Wipe the blade with a clean kitchen towel after each chopping task. Say your recipe calls for a clove of garlic minced, an onion chopped, and a tomato diced. Mince the garlic, wipe your knife dry. Chop the onion, wipe the knife dry. Dice the tomato, wipe the knife dry. This is especially important with acidic foods.
After you're done using your knife, wash it immediately in warm, soapy water. Don't let the knife languish in a sink full of dishes, where it can get dinged up. Under no circumstances should you ever put it in the dishwasher.
Once you've hand-washed your knife, dry it completely right away. And then stow it away. A knife block, a sheath, or a magnetic knife strip are all safe options for your knife. Just don't throw it in a drawer unprotected! (The horror.)
And there you have it! That doesn't sound so hard now, does it? Even Julia Child prefers carbon steel knives (and Julia knows best):
Do you use carbon steel knives? Any care tips you'd like to share?