Washing silver in a dishwasher is strongly discouraged by experts and manufacturers. Placing silver, whether sterling or silver-plated, subjects the metal to an extremely hostile environment that causes permanent damage. The convenience of machine washing is outweighed by the risk of ruining the silver’s finish, which can lead to costly restoration or loss of value. Hand washing remains the only safe method for preserving silver’s luster and integrity.
Why Dishwashers Damage Silver
The physical environment inside a dishwasher is inherently aggressive toward the soft, reactive surface of silver. High temperatures are a primary concern, as the hot water and heated drying cycles accelerate the natural tarnishing process of silver, which is oxidation. This prolonged exposure to heat and moisture can cause the silver to develop a dull, milky finish that is difficult to remove with standard polishing.
Physical damage is also a significant risk due to the intense water jets and the vibration of the wash cycle. Silver items can be scratched or dented when they shift and come into contact with other hard dishes or the metal racks of the dishwasher. This abrasive action is particularly damaging to silver-plated items, where the thin layer of silver can be worn away, exposing the base metal underneath.
The Chemical and Galvanic Risks
The most severe damage to silver in a dishwasher comes from the chemical composition of modern detergents and an electrochemical process known as galvanic corrosion. Dishwasher detergents are highly alkaline and often contain strong chemicals, such as chlorine bleach, phosphates, or citric acid, which are designed to aggressively break down food particles. These powerful cleaning agents react directly with the silver, causing a chemical etching that results in a dull gray or brown discoloration and pitting that cannot be removed by simple polishing.
Galvanic corrosion, or electrolysis, occurs when two different metals, such as silver and stainless steel, touch while submerged in the hot, detergent-filled water. In this reaction, the silver acts as the less noble metal and sacrifices itself, causing silver ions to disassociate and transfer to the stainless steel. This process leaves the silver with deep, irreversible pits and a permanent loss of material. Even if the silver does not physically touch the stainless steel, the presence of both metals in the same wash cycle can still accelerate the corrosion process.
Safe and Recommended Cleaning Methods
The safest method for cleaning silver is immediate hand washing using mild, non-abrasive products. Silver should be washed right after use to prevent food residues, especially acidic or sulfur-containing foods like eggs, from causing tarnish. Use warm water and a few drops of a mild, phosphate-free dish soap, applying it with a soft cloth or sponge to gently clean the surface.
After washing, thoroughly and immediately dry the silver with a soft, clean towel to prevent water spots and the onset of tarnish. For removing existing tarnish, apply a quality silver polish with a soft cloth, ensuring the polishing motion follows the grain of the silver. To prevent future tarnish, silver should be stored in a low-humidity environment, ideally wrapped in tarnish-resistant cloth or placed in anti-tarnish bags.