You go to sleep with a cool, fresh glass of tap water by your bed and wake up to it tasting decidedly…off. Ever so slightly more dirt-like, I’d say. Musty, heavy, or oily, others have said. The taste difference is subtle and hard to describe, in a way that leads people who haven’t noticed to claim it doesn’t exist. So naturally, I called up a scientist to sort things out. […] I also called up a water sommelier, Martin Riese, because that’s a job that apparently exists in LA. —Big Question: Why Does Tap Water Go Stale Overnight?