Salt can be many things: preservative to keep your food from wasting, food additive and flavor keeper. Yes, salt can keep the flavor of the coffee amidst the sugar and the creamer. Coffee originally has a bitter taste. Creamers and sugars hide that bitterness of coffee by almost half. Did you know that saliva can hide the real taste of coffee too? Salt can counteract all the masking effects by creamers, saliva and sugars. Do not overuse salt, though, no one wants salty coffee.