Stainless steel is a durable and popular kitchenware material but its stainless luster can cloud. Such steel alloys consist of least 10.5 percent chromium. This metal reacts with oxygen in the air to produce a protective chromium oxide layer. This layer helps to prevent staining on the steel surface. The addition of nickel and molybdenum improves the resistance to corrosion. Stainless steel is resistant to corrosion and rust at high temperatures but during normal domestic usage, it can acquire a cloudy surface.
Natural waters that flow over limestone regions absorb calcium carbonate and metal ions such as magnesium. This is called hard water and is well known for the cleaning difficulties it causes. It leaves thin deposits of calcium carbonate on the steel surface that prove difficult to remove if not tackled quickly. A mild solution of vinegar or lemon juice with water applied with a soft cloth to the steel surface returns its shine.
The alloys used in stainless steel cooking utensils have better corrosion resistance than the steel used for stainless steel sinks. Particles of the sink surface may loosen and attach themselves to the surface of the utensil when it is soaking in water in the sink. These embedded particles disintegrate and give a cloudy or rusty appearance to the surface of the utensil. The best solution is to avoid prolonged soaking of steel utensils.
The polished finish of stainless steel kitchen appliances, surfaces and counters has a directional grain. Their purpose is to hide minor scratching and to keep the surfaces and appliance looking new. Steel wire or abrasive cleaning utensils will scratch the surface, especially if the cleaning motion has been across the grain. Even a mildly abrasive cleaning cloths could damage and cloud the steel surface.
Potatoes, pasta and rice leave a starchy residue on the sides of a stainless steel pan during cooking. Starchy residue from fabrics builds up on the bottom of an iron. The residues form a cloudy layer. The best option for removal is a mild solution of vinegar in water applied with a soft cloth.
The best cleaner for stainless steel is soap and water. Stainless steel utensils are safe in a dishwasher and do not need prewashing most of the time. Acids and bleaches in strong domestic cleaners will react chemically with the steel surface and leave a dull and cloudy finish. Although mild solutions of vinegar and lemon juice work on the steel surface, for stronger stains the only safe, strong detergent is a solution of 1o percent nitric acid and 90 percent water.