How to Fight Rust on Carbon Steel Kitchen Knives?

When choosing a kitchen knife, one of the choices to make is between stainless steel blades and carbon steel blades. Carbon steel kitchen knives are rated to be the best in terms of durability, edge retaining, and ease of sharpening. However, to get the best out of them, they require more care than stainless steel knives. More so, carbon steel material is prone to rust.

You need to take note of certain key considerations to remove or prevent rust on carbon steel kitchen knives. Today, I hope to teach you, from my personal experience, how you can effectively prevent and remove rust from your carbon steel kitchen knives.

How to Fight Rust on Carbon Steel Kitchen Knives?

Preventing Rust on Carbon Steel Kitchen Knives

It is always better to take steps to preempt rust formation on your kitchen knife than to have to go through the stress of cleaning and restoration after the rust might have formed. Rust forms when atmospheric oxygen reacts with iron content in the knife. Unfortunately, this problem tends to spread and worsen if not checked. To prevent any rust from forming on your knife in the first place, here are some things you can do.

1. Keep Knife Clean and Dry

Proper knife maintenance is a huge part of preventing rust on any knife – stainless or carbon steel. Clean thoroughly and dry properly after each use to get rid of agents that can activate or worsen rust. Personally, I try to clean all my kitchen knives in between use to limit a cross infusion of flavors into the different food items that I have to cut.

Washing the knife under running water should be enough to get rid of all contaminants. You can also wash in mild soapy water before rinsing under running water. However, the most important thing is that you remember to dry with a kitchen towel.

2. Patina

Suppose you’ve had considerable experience with cast iron kitchen knives. In that case, you must have noticed a subtle form of corrosion or coloration forming on the blade after extended use. It is quite different from destructive rust formation as it is much more stable and has a protective effect. One could say it is a method of fighting rust with rust.

Some kitchen knives come with patinas, but you could always build one on your carbon steel knife if yours doesn’t come with it.  With constant use, the patina should develop normally. Still, if you prefer a hurried approach, you can apply a mild acid to speed up the process.

Place the knife in a pan and pour in citrus juice or vinegar until the knife is fully immersed. Leave it for about sixty minutes before taking it out and washing it. You can leave the knife in for longer than an hour if you want a very dark patina.

3. Avoid Acidic Food

Carbon steel knives react to acidic substances faster than stainless steel blades, so you may want to avoid cutting acidic food as much as possible. Well, it would be impossible to completely avoid cutting acidic items with a kitchen knife, but what you can do is limit contact with acidic items. A well-built patina will prevent the destructive effect of acids in the future. However, your blade is pretty much exposed if it doesn’t have a patina.

I have a couple of stainless steel knives dedicated to cutting lemons, limes, and other acidic fruits. You can try this approach. You can also try a similar approach to further protect your carbon steel knives from rust formation.

4. Lubricate

It certainly would help to lubricate your carbon steel knife occasionally. You have to be conscious of your lubricant choice, however. Many oils tend to polymerize and turn into resin-like substances with time. Cleaning them off when they get like that can be hard. I recommend any decent food-grade mineral oil. A simple wipe down of the blade with a small quantity of mineral oil applied to a soft clean fabric will do the job.


The Parts of a Chef Knife?

Forged Vs Stamped Knives: Which Is Better?

Best Damascus Chef Knives

Removing Rust from Carbon Steel Kitchen Knives

Even with proper care and maintenance, it may not be possible to entirely prevent rust from developing on carbon steel knives. There are several proven methods to remove rust, and the most important thing to do is get rid of rust as soon as you notice it. You can try any of or a combination of the following remedies to get rid of rust from your kitchen knives.

What You Need to Remove Rust from Carbon Steel Kitchen Knives?

The supplies you need for rust removal are things you have easy access to. You may not even need to go out to the store to get any.

  • Baking Soda/Vinegar – Depending on which method you prefer
  • Container – To mix the baking soda or hold the vinegar
  • Toothbrush – To scrub the rust away
  • Steel Wool or Abrasive Sponge – To scrub deep rust

1. Baking Soda

Baking soda is one of the gentler agents used to, and it works best on relatively thin blades. To remove rust with baking soda, you need a small mixing container, water, a toothbrush, and an abrasive sponge (for heavy rust). Start by cleaning and drying your knife properly.

Mix the baking soda with water until you get a thickness somewhat like that of toothpaste. With a toothbrush, apply the paste to the rusted sections of the blade. You can cover the entirety of the knife, of it heavily rusted. Next, scrub off the rust and paste with steel wool or an abrasive sponge.

For mild rusts, you can as well scrub the rust off with a toothbrush. However, that may not get rid of all the heavy rust. Finally, wash the knife and dry it properly. Whenever I clean my knives like this, I apply some mineral oil for lubrication and improved protection against rust.

2. Vinegar

This method is perfect for thick carbon steel knives and heavy rusts. Just like with baking soda, you don’t need more than a bowl, a toothbrush, and a steel wool/abrasive sponge. Place the rusted knife/knives into a bowl and pour in vinegar until the blade(s) is covered.

Knives with wooden handles should not be fully immersed in vinegar to prevent damage to the handles. With all the rusted sections covered in vinegar, leave the knife in the solution overnight. Take the knife out and scrub the rust away with a toothbrush. Deep rusts may require more than a toothbrush to scrub.

Steel wool or abrasive sponge should work just fine if a toothbrush can’t effectively scrub the rust away. Be sure to wash the knife with soap and water after the rust removal. Vinegar is safe to ingest but doesn’t taste so good like you probably know. Most importantly, dry the knives completely before you store them away.


An integral part of using any kitchen knife is regular cleaning and maintenance. With carbon steel kitchen knives, maintenance becomes more critical. They are more prone to rust and corrosion than stainless steel knives. Thankfully, taking care of a kitchen knife is not a difficult task. It is always better to prevent rust formation on your knives, but you can easily get them out with simple home remedies if they do ever rust. If you found the information helpful, share it with friends and family who may find it likewise informational. Feel free to drop your thoughts in the comment section below.