I have been using Zalto Denk Art glasses and absolutely love them. I put the Zalto glasses in my dishwasher regularly and they always come out spotless. Due to the recent shortage of Zalto glasses (and my propensity from braking glasses from time to time) I purchased some Grassl glasses, which are also very nice.
Now here is where it gets strange. The Grassl glasses come out completely covered in water spots every time. I can even run both Zalto and Grassl glasses in the same cycle through the dishwasher and the Zalto’s will come out crystal clear while the Grassl’s are covered in spots.
I thought about that but, but they’re both oriented the same way. Bottom rack, upside down. If this was the case the bottom of the bowls would be clearer than the tops as the water ran down (they’re upside down). The Grassl’s are consistently spotted.
I have Zaltos that spot also. Only a few. My Grassl do not spot.
CF - are there mold release reagents? It might have to do with silica content in that particular batch of sand or some other mineral… just guessing though.
I think it’s a function of different glass. I have a lot of different kinds of stems – and water glasses – and they vary a lot in how easily they dry and whether they spot. Similarly, I have some decanters that stain easily while others don’t.
Someone commented in another thread recently about microscopic differences in glass surfaces depending on their composition and how they’re made.
You got me curious, so I Googled. Here are some scanning electron microscope images of two glass surfaces. I couldn’t find any of wine glasses specifically. But you can see that, what looks perfectly flat to the naked eye is anything but at high magnification. Glass is not a crystal, so it has lots of imperfections.
Which reminds me, those old Riedel Burgundy bowls are nasty about spotting. I have to dry them with a towel. There’s something very unusual about the surface of that glass. It streaks easily, too.
It runs counter to our fussy impulses as wine geeks, but the dishwasher is usually the best way to wash stemware. Better results, less risk of breaking, less effort.
It’s a little scary the first times you put your expensive stems in there, but you quickly realize that it’s the best way.