Silver cutlery becomes discoloured, usually a golden yellow colour but in extreme cases this can be brown or even black.
This is not a problem caused by a fault on your dishwasher
Usually the result of:
- Presence of sulphides or chlorides in the wash solution. These can be found in salt, egg, mustard etc.
- Silvery cutlery touching stainless steel items
- Natural oxidation
- Dry detergent poured onto wet cutlery
Cause & Prevention
Tarnishing may well be due to air oxidation caused by allowing the cutlery to stand open to the atmosphere. Tarnishing increases in an environment where there is sulphur content, for example an open coal fire increases the sulphur content of the air.
In a dishwasher the silver is oxidised by the oxygen based based bleach system. The silver oxide reacts with the sulphide or chlorine ions (from egg, salt etc.) to form silver chloride or silver sulphide. The tarnish will start as a yellow but in time will become black.
Silver can also react directly with suphides to form silver sulphide.
Detergent left in contact with wet cutlery will result in tarnishing and of course, contact with stainless steel will also cause tarnishing.
Tarnish can be removed using a proprietary silver cleaner.
You can minimise the risk of air oxidation by storing silver cutlery in a closed box.
This is a hassle but the risk, when washing silver items in a dishwasher, can be minimised by removing any egg, mustard or other chloride or sulphide containing material form the table ware before washing. In other words, rinse the cutlery off before placing it in the dishwasher or don't wash silver in the dishwasher.
Ensure that silver and stainless steel are kept separate.
Do not pour detergent onto the cutlery and, whenever possible, start the dishwasher immediately after loading.
How You Can Get Help With Dishwasher Problems
To offer support in helping people to determine the cause of dishwasher problems please use the dishwasher support forum.
It’s fast, free, easy and normally someone will pick up on the post that can assist you often with a few experts chipping in if needed. Just register if you don’t have an account, we don’t mail you, send you spam or any of that stuff.
Post up your question and give images if you possibly can and the guys in the forums will do the rest for you and try to identify the problem you have.
Cost you nothing, might save you some embarrassment or worse, a charge for a service visit that wasn’t needed.
Photographs Of Damage
If you can post photographs of the damage or problem you are having this can be really helpful in allowing the dishwasher technicians to see what the problem is.
The guys have the knowledge to assist with most problems but the more information you give them, the better they can help you.