How to Clean and Polish Stainless Steel

What is Stainless Steel?

Stainless steels are iron alloys with a minimum of 10.5% chromium, which has a high polish, resists tarnishing and has a very high melting point (over 2,600ºC), making it perfect for use in commercial kitchens. As well as chromium, other alloying elements such as nickel, molybdenum, titanium, copper, nitrogen and carbon are added to enhance the strength, formability and cryogenic toughness (the strength and toughness under very hot or very cold conditions).

There are many grades of stainless steel, but the most common are;

• 304 or 18-10 - this is a commercial grade of stainless steel, used in most tables, sinks and cutlery. For cutlery, the numbers represent the chromium and nickel contents of the steel respectively: 18% chromium and 10% nickel. This metal is called austenitic and is not magnetic.
• 430 or 18-0 - this steel contains 0% nickel, giving it less resistance to corrosion, making it slightly less durable but cheaper to make. This metal is called ferritic and is magnetic.

Stainless steels have a protective layer surrounding them, millionths of an inch thick, created by the mixing of all the elements. This protective layer can be damaged and so needs to be maintained. The three main things that can damage this layer are abrasion, from cookware, knives, packaging and just about anything else, deposits of food and water, and chlorides found in cleaning chemicals and food.

TIP: A common misconception about stainless steel is that it can’t rust. However, this is not the case –
although stainless steel is highly resistant to pitting and staining, it is stain less, not stain proof.

How to Clean Stainless Steel Tables, Sinks & Appliances

Cleaning stainless steel is fairly easy, and when done regularly, can increase the longevity on your tables, sinks and cooking equipment, saving you time and money.

• Remove all food and water deposits from the surface with a microfibre cloth or soft sponge. Then go over with a stainless steel cleaner to ensure all dried on stains are removed. Be sure to choose a cleaner with alkaline and without chloride in it.
• Use a metal or stainless steel polish. Most stainless steel surfaces will have a ‘grain’ which runs along the surface. Use these lines as a guide for polishing, ensuring you polish along them, rather than across them.
• Be sure not to use abrasive cleaning products such as scouring pads or wire pads. These will scratch the surface, destroying the protective film which can cause rust.

TIP: Deposits left on stainless steel will work to corrode it, causing rust and damaging the surface, so it’s best practice to clean your tables after every use, or at the end of each service.

How to Clean Stainless Steel Cookware

Cleaning and caring for cookware is very similar to cutlery and tables, but there are a few extra points to consider, ensuring your pots, pans, trays and more stay in top condition.

• Always dissolve salt in boiling water. Adding salt to an empty pan can cause pitting, a form of localised corrosion that creates small holes in the surface.
• Where possible, always wash stainless steel cookware by hand and with soft or non-abrasive cleaning tools. Similarly to tables, scouring pads and wire brushes can scratch the protective film from your cookware, damaging the surface and opening it to rust.
• Metal utensils also have the same effect, so it’s best to use plastic, rubber or wooden utensils when preparing, cooking and serving food.

TIP: Cast iron cookware is different to stainless steel cookware and the same cleaning rules do not apply. Visit our guide to seasoning and caring for cast iron cookware to find out how to keep yours pristine.

Article: Caring for cutlery is also slightly different. Take a look at our how to look after cutlery properly guide for everything you need to know.

FAQs

How many types of stainless steel are there?

There are 5 types of stainless steel:

• Ferritic - based on chromium with small amounts of carbon, these steels have a wide variety of applications and are perfect for use in aggressive conditions such as commercial kitchens or near the sea (high salt water resistance). Magnetic.
• Austenitic - the most common type of stainless steel, these steels have added nickel, manganese and nitrogen which makes them stronger. The addition of nickel gives them an increased resistance to stress corrosion cracking. Non-magnetic.
• Martensitic - similar to ferritic steels (also based on chromium), these steels have higher carbon levels which allows them to be hardened and tempered. Suitable for use in areas where high strength and moderate corrosion resistance is needed. Magnetic.
• Duplex - these steels are 50% ferritic and 50% austenitic, giving them higher strength than both and enhanced resistance to stress corrosion cracking. Magnetic.
• Precipitation hardening (PH) - these possess added elements such as copper, niobium and aluminium, which gives them high strength and allows them to be heat treated for even greater durability. Their corrosion resistance is comparable to austenitic steels.

Why does stainless steel rust/corrode?

Although stainless steels have high resistance to corrosion and rusting, aggressive conditions (such as in commercial kitchens) can damage the protective layer and allow for oxidization (the loss of electrons from atoms). This is a natural process that happens to anything from tables to fruit.

What is stainless steel made from?

Stainless steels are an alloy and so vary in their make up, but they can contain carbon, chromium, nickel, molybenum, silicon and aluminium.

Can I use stainless steel at high/low temperatures?

Yes. Stainless steel is an extremely hard wearing and durable alloy that can be used in temperatures ranging from -268ºC to over 2,600ºC. Not every stainless steel has this range, as some are more resilient than others.

What cleaning product should I use to clean stainless steel?

There are a number of cleaning products you can use to bring back the shine to your stainless steel surfaces, from household ingredients to professional cleaning chemicals. Vinegar and oil is a favourite in domestic kitchens and home, but it can leave a greasy residue that makes the surface unpleasant to touch and dangerous, as it becomes slightly sticky. This also isn’t appropriate for any surface where food is going to be prepared, so is best avoided in commercial kitchens.

A food safe stainless steel cleaner and polish offers a safe and extremely effective method of cleaning and polishing tables, sinks and other kitchen equipment. You should also avoid using chemicals with chloride in them, as this has a corrosive effect on the stainless finish. Microfibre or other non-abrasive cloths should be used and pushed in the direction of the ‘grain’ of the stainless steel.

Can I put stainless steel products in the dishwasher?

Stainless steel is susceptible to pitting and rusting when soaked or left wet, therefore it is generally advised that you don’t wash your stainless steel cookware or cutlery in a dishwasher. However, you can wash stainless steel items through a dishwasher if placed far enough apart to ensure proper drying. Washing and drying pots, pans and cutlery by hand is the only sure way to ensure no water or food residue is left on their surface, so we advise you refrain from using dish washing machines.

Why do I need a stainless steel sink and countertops?

When it comes to choosing the perfect commercial kitchen sink or kitchen work table, you must consider multiple factors that will affect not only you, but your customers too. 304 stainless steel is a food grade alloy that is extremely easy to clean and therefore extremely hygienic, making it safe to prepare food on. This reduces the risk of causing food poising by cross contamination when preparing dishes in busy commercial kitchens. The same levels of hygiene cannot be achieved with other materials, such as wood or plastic. Stainless steel is also relatively inexpensive to buy around the world, making any table, sink or cooking appliance you buy less expensive to replace if it breaks.

Article: Not sure which sink you need for your kitchen? Take a look at our guide: which commercial kitchen sink to choose.