Our Conservation Department has the following advice:
Unfortunately the cloudiness is likely surface deterioration and there really isn’t anything that can be done for that. The best thing for the glass is to wash with a mild detergent and rinse well with deionized or distilled water (these don’t have minerals, so there won’t be any water spots). They can be air dried or towel dried. They should be stored/displayed in a way that allows for air movement because any trapped moisture can cause further deterioration.
You can read more about how our Conservation Department approaches this and other problems in the blog post "Washing Glass."
Want to Learn More?
You also might be interested in the book Conservation and Care of Glass Objects by Stephen Koob, which includes a chapter on cleaning glass.
Please don't hesitate to contact us with your glass-related questions in the future!
