Why is it that water tastes better from a glass than a cup?

[bailysky]

Why is it that water tastes better from a glass than a cup?
Just one of those random questions that come to me on a slow day. I thought about posting it in General, but seriously - there must be some natural explanation?

[Casiopea]

Welcome, bailysky.

Two reasons:

(1) glass is more expensive than plastic or clay.
(2) you can see the water in the glass; you can't see it as well through plastic or clay.