The taste of water

Due to the recent purchase of some posh lip gloss (i.e. cost more than $15 and came from Kirks) I thought I should be more lady-like at work with regard to my water intake and not chug away on my Pump bottle, which no longer has a smooth exterior but is crumpled from months of use. So, I opted for the tall glass of water. Which was fine for the first few mouthfuls. But then it began to taste funny, that taste water gets after it’s been sitting around for a while. I’m intrigued as this doesn’t occur with the bottle of water – I filled the glass from the exact same source and at about the same time as I have done for the bottle over the past few months. Must be something to do with the contact with the air I guess …