I think water definitely has a part in this, but I am suspecting the home freezer type of gradual temperature change may cause actual chemical changes in some of the less stable materials in the tealeaves. I am still lacking time to look into this aspect so I can not point a finger at anything.
Fine tea holds so many different substances in it to make it fine and so many of them are so delicate. They give us the subtlety in the experience and yet they can be gone so easily. So much the same in that many other things in life.
