I don't know, but can I guess anyway? <img src="/forums/images/graemlins/tongue.gif" alt="" />
Since taste comes mostly from odor, and since some iodine is absorbed by plastic containers but not by SS containers, you're not smelling it from both the container and the water with your metal bottle. I really doubt there's any sort of chemical inactivation going on.
That's all I've got!
The last backpack trip we went on, we took our new stainless steel water bottles, and treated with iodine as we usually do. (Yes, I know they're not lightweight!) The surprising thing is that the water did not seem to have the usual yucky flavor of iodine that we had in our old Lexan and Nalgene plastic bottles. Anyone have an explanation for this?
I'm assuming it's not that the steel inactivates the iodine, or they'd have a warning on iodine water treatment products. I've pretty much decided to take my stainless steel bottle again this week, just for the more pleasant taste.