Answer: The foggy glasses are likely caused by hard water buildup. Try cleaning the glasses with vinegar from time to time and use a rinse agent in the dishwasher. If you have a water softener it may not be functioning properly. Make sure it is recycling.
The problem may be permanent if the glass is “etched”.
Here’s how to tell:
- In a glass pie plate, soak one side of the affected glass in vinegar for one hour.
- Remove the glass, rinse and dry. Hold the glass up to the light.
- If the side soaked in vinegar looks different from the unsoaked side, the film is probably the result of hard water buildup.
- If there is no difference between the two sides, the film is caused by a chemical reaction between some types of glassware and the water and/or detergent. This is permanent etching.
Make sure the glassware you purchase is dishwasher safe.
Source: The Case of the Sparkling Dishes Automatic Dishwashing for the 21st Centurypublished by The Soap and Detergent Association.