If you wanted to proceed as professional cuppers would, assemble identical clean cups or shallow, wide-mouthed glasses (capacity 5 to 6 ounces) for each coffee to be sampled; a soup spoon with a round bowl; a glass of water in which to rinse the spoon between samplings; and something to spit into.
Put one standard measure (2 level tablespoons) of each coffee to be sampled, freshly and finely ground, in each cup; pour 5 to 6 ounces of not-quite-boiling water over each sample. Some of the grounds will sink to the bottom of the cup, and some will form a crust on the surface of the coffee.
Wait a couple of minutes for the coffee to steep, then test each coffee for aroma. Take the spoon and, leaning over the cup, break the crust. Virtually stick your nose in the coffee, forget your manners, and sniff. The aroma will never be more distinct than at this moment. If you want to sample the aroma a second time, lift some of the grounds from the bottom of the cup to the surface, and sniff again.
After you have broken the crust, most of the grounds should settle to the bottom of the cup. Use the spoon to scoop up froth and whatever grounds remain floating on the surface and dump them into the improvised spittoon. Top off the cup with fresh hot water. Now take a spoonful of each coffee, lift it to a point just below your lips, and suck it violently into your mouth while taking a breath. The purpose is to spray coffee all over your tongue while drawing it into your nasal passages in order to experience a single, comprehensive jolt of flavor.
This inhaling of coffee spray should give you a notion of the nose of the coffee, or the pure aromatic elements of its flavor. Now roll the mouthful of coffee around your tongue, bounce it, chew it even. This exercise should give you a sense of both the body or mouthfeel of the coffee, as well as its flavor as influenced by both aromatics and fundamental tastes, particularly sweetness and acidity. Also note how the sensation of the coffee develops after the first impression. Note whether it changes and deepens, or whether it becomes weaker or flatter; whether it sweetens and softens, or hardens. After all this, spit out the coffee, noting the aftertaste.
Continue this procedure until you can distinguish the qualities I discuss in the following pages. Take your time, and feel free to simply take mouthfuls and experience them without the often distracting inhaling business. It is a good idea to concentrate successively on each of the broad tasting categories; i.e. taste all three samples for acidity; then taste all three for body; then for flavor and finish; and finally for aftertaste. Always continue to taste as the coffee cools. Some characteristics reveal themselves most clearly at room temperature. If your palate becomes jaded or confused, sip some water or nibble on a bit of unsalted soda cracker.