When people attending a meeting– particularly a meeting that starts at 8am on a Saturday– elect to drink tea rather than coffee, they do so because they do not want coffee. For this reason, it is imperative that you not select the urns at random from a large pile of them, but rather use urns for hot water that have not been used for coffee.
If I wanted brownish coffee-flavored hot water, I would drink coffee, and not bother with the tea bags.
Thank you.

