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How To Remove Rust From Knives With Baking Soda

Most people have heard of the cleaning powers of baking soda. In the kitchen, baking soda is often used to clean sinks and ovens. But how can baking soda help with removing rust from knives?

Two Quick And Simple Ways

Baking Soda and Water

For this method you are going to make a paste out of only two ingredients: water and baking soda.

In a small bowl, mix a small amount of baking soda with a small amount of water. It will end up being about twice as much baking soda as water. Simply combine the water and baking soda until you have formed a paste. You won’t need much as you only need however much it takes to spread over the knife or knives you are cleaning.

Meanwhile, wash your knife with dish soap and rinse. Apply the newly made paste over all of the metal parts of the knife. If your knife is very dirty / rusty, you may let it sit for about 10 minutes, but you don’t have to.

You are now going to scrub the paste off of the knife. How hard do you need to scrub? That depends on how bad the rust is. You can use steel wool or something similar to really work at severely rusted areas. For lightly damaged areas or areas with no rust at all, you can certainly just use an old towel or old toothbrush.

Important: If you use steel wool, be careful not to damage your knife.

Rinse the knife thoroughly, examine the results, and repeat if needed.

How To Remove Rust From Knives With Baking Soda
Baking Soda is one of the most versatile supplies in your kitchen

Baking Soda and Toothpaste

For the baking soda and toothpaste method, you don’t have to create a paste – you start with one!

In a small bowl, drop in about as much toothpaste as it would take to coat your blade with a small amount of toothpaste. Add small amounts of baking soda and gently mix until the toothpaste is saturated with baking soda.

Again, clean your knife, apply the paste, wait a few minutes, and scrub with an old towel / toothbrush or steel wool as necessary.

Thoroughly rinse and inspect the knife, repeating the process as needed.

How To Remove Rust From Knives With Baking Soda
Combining Baking Soda with an acid makes a powerful cleaner

Three Longer Methods For Tough Rust

For all three of the methods below, you will start with making a baking soda paste as above.

Also for all three methods below, I recommend that you wear gloves and rinse any baking soda mixture from your skin as soon as possible.

These methods are only necessary for knives with a lot of rust.

Baking Soda and Vinegar

After you have your baking soda paste made and ready, soak your knife in white vinegar for up to five minutes. Remove the knife from the vinegar but do not dry the blade.

Important: If you leave your knife in vinegar for more than five minutes your blade may be damaged by the acetic acid in the vinegar

Apply your baking soda paste to the blade with a toothbrush.

The small amount of vinegar still on the blade will react with the baking soda paste all along the knife on a very small scale. You may not be able to see this happen, but it will be happening all along and throughout the iron oxide (rust) on your knife. This action will help to dislodge the rust.

After you have applied the paste, go ahead and scrub with a toothbrush, old towel, or steel wool as appropriate.

Be sure to carefully rinse the knife, wear gloves, and wash any vinegar / baking soda mixture off of your skin immediately.

Video: This reaction will be happening on a small scale all along your knife with the baking soda and acid method

Baking Soda and Cola

You can follow the same steps in the section above, substituting cola for the vinegar.

With cola, the phosphoric acid and the carbonization (CO2) both contribute to the foaming action that helps to clean the rust off of the knife.

Again, while the tiny amount of cola left on the blade may not be enough to make a reaction large enough for you to see, the rust on your blade will be disrupted as the reaction happens on a small scale.

As noted above, use gloves and keep your skin free of the cola and baking soda mixture.

Baking Soda and Citric Acid

The vinegar and baking soda mix relies on acetic acid, while the cola and baking soda mix relies on phosphoric acid. This third baking soda and acid mix relies on citric acid.

Citric Acid is easy to find – in citrus fruit. Lemon juice and lime juice are your best bets. You can use the bottle juices or squeeze the juice right from a fruit.

Follow the same instructions as with the cola and white vinegar above. Wear gloves and keep the citric acid and baking soda mixture off of your skin.

How To Remove Rust From Knives With Baking Soda
Regardless of which baking soda method you use, be sure to rinse your knife

Removing Rust From A Knife Video

This is a great video which shows the baking soda paste and how to apply it starting at about 0:50…


Baking Soda is an amazing cleaning product through your entire house. From the laundry to the bathroom and the kitchen (even in your food), this inexpensive compound is one of the most useful items you can have in your pantry.

There are five very easy ways to remove rust from a knife with baking soda:

  • With a baking soda and water paste
  • With toothpaste mixed with baking soda
  • Vinegar (Acetic Acid) and baking soda
  • Cola (Phosphoric Acid) and baking soda
  • Citric Acid (lime juice / lemon juice) and baking soda

Make sure to be safe and enjoy your soon to be rust free knives!