In Australia, working for Trapdoor Productions, we would often get coffee together on monday morning as a way to start the week and discuss client work. The first time I joined in, having ordered my caffe latte, I wanted to put in some sugar. I do this, and my two colleagues look at me, mouths open and shocked. One asks: why are you adding salt to your coffee?
Being a stubborn kid, I drank it anyway, and to this day have stayed far away from salt when coffee is involved.
I was very surprised to find out then, that a small touch of salt can actually counteract that stingy bitter taste coffee sometimes has. Somebody studying taste buds will probably confirm this someday.
Next time you have a cup of coffee, give it a try. You really only want a pinch of salt (the amount you can carry by pinching together two fingers).