An ideal cup of coffee should have good aroma, good color (if milk or cream is to be added), good body, and good tastes for whichever way the coffee will be roasted, brewed and served at any intended time of day. Out of the millions of bags of coffee processed every year, relatively few can provide the "ideal cup" criteria without a little help from their friends, the other coffees with whom they will be blended. Regarding the few that can stand alone, they will probably not provide an all-round, perfect, well-balanced cup; rather, they will have one or two particularly fine points which more than compensate for falling short on another aspect or two.

Balancing Flavors
Each coffee used in a blend should make its own contribution. Dark roasting hides the not-so-desirable flavors of robust as, and of other coffees which may happen to have lower acidity, but usually have good body, which is only enhanced by the dark roast. Conversely, many high-grown Arabica, while producing a sharp flavor that can dominate the overall tastes of other less acidic coffees, are "thin-in-the-cup", and lack body. With these watery Arabica, the solution is not to roast darker, as roasting burns off the acids that contribute to the sharp, "expensive" taste. Other coffees may be pleasantly acceptable, having no particularly distinctive quality either to recommend or condemn them; these neutrals are ideal for bulking out a blend, as their flavors are not obtrusive, nor are they lacking in body.

There are no rules or taboos in blending coffees, but the idea is to combine coffees that complement each other, not those that are similar. A good starting point, therefore, for a middle-of the-road, any-time-of-day well-rounded cup of coffee, would be a blend of perhaps 35 per cent high-grown Arabica to provide the dominant flavor, 15 per cent darker-roasted Robusta or heavier-bodied, lower-acidity coffee to provide the body, and 50 per cent of a more neutral and possibly more affordable coffee, like an average Brazilian Santos, or one of the slightly lower quality and less expensive Central American coffees. The character of this blend could be changed considerably just by altering the proportions. Also, lowering the proportions of each would allow for the addition of a small amount of a different, fourth, coffee, perhaps an unwashed Arabica, as most "natural" Arabica are known for their sweetness.

All blends should be worked out in percentage weights with a taste or style in mind, whether the overall blend is to be, for example, a "fruity" blend; a "mild" breakfast coffee; a deep, rich, syrupy after-dinner indulgence; a naturally low-caffeine blend; a high-caffeine "pick-me-up" with lots of caffeine-rich Robusta; or perhaps simply a strong-flavored coffee to provide the basis of an alcoholic coffee cocktail. If a blend is to be used often and remain consistent, the availability and affordability of each particular coffee must be considered.

Classic Combinations
A few combinations of particular coffees are so successful that they have become standards through the years. Mocha (either from Yemen or a reasonable second from Ethiopia) and Mysore from India are the most famous coffee marriage. Mocha-Java will be a bit earthier and heavy, but still winey, and wild (or gamey) from the Mocha. A very particular Mocha-Brazil combination is that favored by Middle-Eastern roasters for the traditional "Turkish" coffee flavor: the Brazilian coffee is the famous, or infamous, rio-y flavor. A good Brazilian Santos will smooth out an average Robusta to make a strong, smooth blend, while a blend requiring some lightness can be illuminated by the addition of some Kenyan coffee, or a high-grown Central American. A Haiti or a Peruvian adds some decent flavor without being too expensive. An aged coffee adds sweetness, and a Colombian can add aroma as well as body and flavor.

In America, a "New Orleans Blend", and in Britain a "French Blend", neither to be confused with any degree of roast, is a blend of coffee and the roots of the chicory plant, just as a "Viennese" blend in Britain contains roasted fig or fig-seasoning ground in with the coffee. Of these two "economy" blends, the Viennese is cheaper, being the least expensive coffee blend of the average British supermarket range.