Stainless steel knives are a great choice for kitchen use but they are not indestructible. They will rust if they are exposed to the elements.
Stainless steel is more resistant to rust than carbon steel but it’s not 100% rust-proof. The passive chromium oxide layer on the blade acts as a barrier to prevent oxygen from reaching the iron and forming rust.
1. Lack of Oxygen
If you have stainless steel knives in your kitchen, you may wonder why they rust. Although stainless steel is more resistant to corrosion than carbon steel, a lack of oxygen can cause the blades to rust.
Rust is formed when iron and oxygen combine in a chemical reaction called oxidation. This corrodes the metal, leaving an orange-red substance on the surface.
However, rust does not pose a health risk. It only affects the food that is cut from a rusted knife, and it won’t impact the person using the knife.
If you want to remove rust from your knife, there are a few different methods. One is to wash your knife with soap and water and then dry it thoroughly before storing it. Another is to soak your knife in vinegar for a few minutes. Then, wipe it with a dry cloth. Finally, you can apply a coat of mineral oil to the blades before storing them away.
2. Water
If your knives are stored in a damp area, or you keep them in the sink for longer than you’d like, they could start to rust. It’s a natural reaction of oxygen and iron.
This is why you’ll find that if you use abrasive sponges and scourers on stainless steel, it will leave a pit or rust spot.
Fortunately, these spots can be removed with a few home remedies.
Baking soda and lemon juice are a couple of common ingredients that you can mix to make a paste which is very effective for removing rust from your knives.
You can also add a few drops of citric acid into the baking soda and mix to create a stronger paste which is more effective. You can either spray it directly onto the knife blade or add it to a paste and rub it in. You’ll see that it works quite well and if you use the right amount and leave it on long enough, you should be able to remove all of your rust.
3. Food
When stainless steel comes into contact with acidic substances such as water, rust will eventually form. However, a small amount of rust on your knife is not dangerous at all.
It is not harmful and it does not affect the way food is prepared. It is only when you have a large amount of rust that it can contaminate the food that you are using to prepare and it can be harmful to your health.
The good news is that you can easily remove rust from your stainless steel knife. To do this, all you need to do is follow some simple and safe steps.
The first step is to ensure that your knives are dry. This can be done by putting them in a dry place when you are not using them. You can also use a damp cloth to wipe them down before you put them away.
4. Chemical Corrosion
Rust is a chemical compound that can easily be formed when metal alloys come in contact with moisture and acidic substances. This can be a problem especially when knives are left in damp areas, or are used with salty food remnants.
The Statue of Liberty in New York, for example, rusted to a greenish patina over time due to corrosion. While this is usually harmless, it can cause serious damage to metal objects.
Carbon steels are very susceptible to rust when they are exposed to moisture and acidic substances. However, stainless steels are resistant to rusting, thanks to their high chrome content.
This is why you should always keep your stainless steel knives dry. If you are planning to use them in humid or coastal environments, you should consider purchasing knives that have a special coating for better protection. Alternatively, you can also apply vegetable oil to the blades during storage. This will help prevent the development of rust and prolong their life.