Between 3 and 6. I need at least 2 to get my heart started in the morning, and the first has to be REAL coffee (not instant) and strong enough to stand up and fight me. Black and the stuff has to be suitable for mending roads. Let me put it this way - if the spoon stands up, it's too weak. It it starts to dissolve, that's better, but when that spoon jumps out of the mug and runs away screaming in mortal agony ... then it's PERFECT.