Dishwashing Dilemma – It’s All About Chemistry
Written by Charleston
Although sources close to the dishwasher – the “dunk it in vinegar” squad – have instructed us otherwise, Winter Park wine taster Ann Foray maintains that the film on glassware is called “etching” and it is not reversible.
“Your glassware has been permanently damaged by some (what, I don’t know) ingredient in your automatic dishwasher detergent,” she said. ”I use Diamond Brite by Melaleuca, only available by ordering online. It does not etch your glassware. It is completely safe, and you use much less than other brands. This issue is very frustrating, and you don’t know if this is going to happen to your glassware until it’s too late.”
The dishwasher manufacturer Miele has this to say of the issue:
Etching is the removal of metal ions from glass by alkaline wash solutions. Generally, everyday glasses and inexpensive crystal are made of ingredients that will show signs of some etching over time.
Etching is aided by pre-rinsing the dishes, insufficient water volume, too-soft water, too-hot water and not using rinse aid.
Once the etching process has begun, it cannot be reversed, Foray is right…so, Miele’s solution:
Use a minimum amount of dishwashing detergent. One teaspoon of detergent in the detergent cup is usually sufficient. If the dishes are exceptionally dirty, add extra detergent by the half teaspoon.
Use the maximum water level allowed by the dishwasher. More water allows for better rinsing and a higher dilution of the detergent. Use lower-temperature wash programs. Higher temperatures lower the resistance of a glass to etching.
Do not use oversoft water. Very soft water is extra reactive and will pull additional minerals from the glasses and dishware.
Load the dishwasher correctly. Correct loading ensures thorough rinsing of the glasses and dishes.
Use a rinse aid, which conditions the surface of the water so that it will sheet off the glass and thereby reduce the time available for chemical reactions with the glass.