Why can stainless steel knives still rust?

As discussed in previous articles: stainless steel is about making the best compromise for the application. Some knives will rust right before your eyes, and others can survive in saline conditions without oxidizing. Not to worry, keeping your knives rust free is a breeze.

Rust resistance is a part of the chemical balancing act when designing a steel alloy. In kitchen knives sharpness plays a big role too obviously. Sharper is better. Some knifemakers take this to the extreme and will readily sacrifice rust resistance for a harder and sharper blade.

ABOUT CARBON AND CHROMIUM

The primary element in most alloys that increased a steel’s susceptibility to rust is carbon. The more carbon, the easier the alloy will oxidize. More carbon also means a steel that can be tempered to be harder.

To compensate for this chromium is added. The more chromium, the more rust resistant a steel is. However, chromium also decreases the steel’s ability to take and hold a sharp edge. So too much can be a bad thing.

The steel we use at BARE Cookware is very rust resistant. We’ve struck a balance between hardness and rust resistance. Our steel is hardened to 58 HRC while remaining rust resistant. But just like any steel can rust if subjected to certain conditions. Let’s take a look at risk factors for rust forming.

ACID, SALT, MOISTURE, HEAT

Acid, salt, and moisture will all act as a catalyst and speed up oxidization. Acid can reach kitchen knives in numerous ways. Think fruit-juice, vinegar, and even the moisture that naturally occurs on your skin. Salt is used in just about every dish, moisture is as abundant in a kitchen as is heat.

A special mention should be made about sea-air. In coastal regions the air is both humid and high in minerals (salty). Extra care should be taken to store knives in a dry area.

HOW TO CLEAN RUST

Eventually rust can form on any steel, even stainless steel. So how to keep your knife gorgeous and rust free? It is important to scrub off any surface discoloration before the oxidation starts to eat into the steel. We advise to do this with a scrubbing sponge and some dishwashing detergent. If that is not strong enough a piece of steel wool can be used.

Only when the rust is more developed would we ever want to break out the big guns. Think fine grit sandpaper and brake cleaner. It should be clear that this is always to be avoided. That brings us to our most important point to keep your knives rust free.

HOW TO PREVENT RUST

Luckily preventing rust is a simple 3 step routine:

1. Clean the blade by hand after every use. A quick rinse will usually suffice.

2. Dry the blade before storing it.

3. Never ever put a high-quality knife in the dishwasher.

Do not postpone this. Do not leave your kitchen knives lying around dirty. It is unsafe, unhygienic and promotes oxidation. After years of following this simple habit we've yet to see any rust on the BARE Knives we personally use. Interested in more knife care? Here you go!

A good quality kitchen knife will last a lifetime. If taken care of properly. Knife maintenance is easy and costs little to no time at all. It’s a matter of habit really. Adopt the right cooking habits and you are rewarded with a tool that stays sharper for longer and will probably outlast you. We have 4 simple tips for basic knife maintenance.

Cutting

To keep your knife as sharp as possible during cutting you should avoid cutting into anything that will dull the knife more rapidly. Because the steel of your knife is hardened it is also more brittle. This means that a knife can chip when abused. Here’s some pointers how to properly use your knife:

• Use the right knife for the right task. Don’t use a Chef’s Knife to hack through bones for example. Use a cleaver for that. Generally speaking, using a knife should not require much force. If it does, than you are probably using the knife for something it wasn’t meant for
• Use the right cutting board. Avoid cutting on anything hard like stoneware, steel, glass, or marble. This will dull the knife or even cause it to chip. Kitchen knives should be used on a soft cutting board. We prefer wooden cutting boards. They look nicer and are better for the planet. But plastic boards work almost as well.
• Do not put lateral pressure on the blade edge. This means: do not push or scrape the blade side to side. This will cause the sharp edge to roll over or chip. Need to scrape something of a board? Use the back of the knife!

Cleaning

The best way to cut down on knife maintenance is cleaning you knives the right way.

• Even though some knives are dishwasher safe, we always recommend you to hand wash your knives directly after use. BARE Knives are NOT dishwasher safe due to the wooden handle.
• Do not let your knife sit for too long with food residue on it. Especially acid foods may cause the blade to stain. Though this can be scrubbed off, it’s better to be avoided altogether.
• To wash your knife simply use some dishwashing detergent and a non-abrasive sponge or brush. Dry the knife carefully. Keep the sharp blade away from you during washing and preferably lay the knife flat on the bottom of the sink. This way you minimize the risk of cutting yourself accidentally during cleaning.

Storing

Perhaps just as important in your knife maintenance routine is how you store your knives

• Store your knives in a dry place so they don’t stain or rust. Even stainless steel knives can rust over time. 
• Keep your knives from banging into other knives or utensils. This would dull the blade. Therefore, do not throw them carelessly into the kitchen drawer. Use a knife block or a magnet strip. (We happen to sell such a magnet strip)
• Most importantly: store your kitchen knives out of reach from children. 

Periodical care

Every once and again you will need to touch up your kitchen knives. Here are a couple things you can to to keep your knives in tip-top shape.

• Sharpening the blade. Eventually every sharp blade will dull with use. You can sharpen the blade yourself or have it sharpened by a professional. You can find more information about the first option here. If you want your blades sharpened by a pro we recommend asking at your local kitchen specialty shop.
• If your blade has a wooden handle: apply oil to the handle. To keep a wooden handle in water resistant it needs to be oiled. We recommend once every two or three months for the first year of use, and once every 6 months every year thereafter.
• After lots of use a little discoloration or rust can form on your knife. Don't worry, this is easily dealt with. Here you can find how.

A quality knife taken care of will last you a lifetime. That means caring for the natural hardwood handle too! BARE Knives are all fitted with a natural wenge hardwood handle. Our handles are sustainably forested, CO2 compensated, and just feel right in the hand. Wood-care really boils down to oiling the wood every now and again. Let’s talk about specifics!

When to oil?

The guidelines in this how to apply to most wooden surfaces. Like found on our magnet strip for example. Cutting boards should be maintained just the same, but make sure to choose food-safe non-hardening oils. 

A good rule of thumb is to oil any wooden kitchen utensils every month the first year after purchase. After the first year once every year should suffice. We recommend going by eye here. If the wood looks dull or dried out: it’s time to oil.

Please note: wood that has been treated with a layer of paint or lacquer should never be oiled. 

Why do you need to care for wooden handles?

Wood dries out slowly over time. Some types of wood faster than others. Our hardwood Wenge handle is very rich in natural oils. This means it will take quite a while to show any signs of wear and requires little maintenance. But eventually any wood can dry to the point where it will crack. To prevent that we need to moisturize it with oil. Furthermore: oil will bring out the natural grain of the wood and make it more beautiful. What’s not to like?

What oil to choose?

This really comes down to personal preference. Here are a couple solid options:

• Mineral oil
  • Our favorite option. Widely available (at IKEA for example), cheap, odorless, flavorless, and food-safe. Mineral oil is perfect for cutting boards too. Excess oil should be rubbed off. Mineral oil is non-hardening so will not leave a sticky residue. 
• Grapeseed oil
  • Grapeseed oil is also a good option for your wooden surfaces. It is a good bit more expensive and harder to come by but works much like mineral oil.
• 'Cutting board oil'
  • If you search the web you'll find special cutting board oil. Most of these products are blends of different non-hardening food safe oils. So while a tad on the expensive side, fine for handles, cutting boards and any knife handles.
• Almond oil
  • Again a non-hardening food safe oil, fine for most wooden surfaces. However, any nut-oils could trigger allergic reactions in people with nut allergies, therefore we would not recommend it.
• Boiled linseed oil
  • This oil is hardening and not safe for cutting boards. An age-old choice among woodworkers. Boiled linseed oil leaves a beautiful patina that polishes over time with sustained use. As with Danish oil any excess should be carefully removed as this oil will harden to leave a lacquer like layer.

How to apply?

Simple! Just take an old rag and rub some oil on the handle, magnet strip or any hardwooden surface. Give the wood some time to soak up the oil. About an hour will do, but longer can't hurt. Then clean off any excess oil with a dry rag. If the wood absorbs all the oil and feels dry, simply repeat the process. Hardening oils should be left to set for a day, mineral oil can be used straight away. 

Why wouldn't you just use cooking oils?

In a pinch any oil is better than none. However: cooking oils will leave your handle or cutting board tacky and can leave a rancid smell over time. So we do not recommend using cooking oils on your wooden surfaces.

More about general knife maintenance can be found here.