Coffee tasting (also called 'cupping') is the sensory evaluation of Acidity, Aroma, Body and Flavour.
Acidity: refers to the 'liveliness' or brightness of the cup, which is characteristic of high-grade arabica coffees. Think fruity, winy, sharpness in the cup. The longer/darker the roast, the more the coffee loses this characteristic, which can leave a coffee dull and flat.
Aroma: refers to the odour of the brewed coffee. Fragrance refers to the smell of the dry coffee grounds before brewing. Smell is an essential element to the cupping process and sensory evaluation of the coffee.
Body: refers to the weight or texture of the coffee in the mouth. It is described as:
Flavour: Leading taste specialists now believe that saltiness, bitterness, sweetness and sourness can be tasted everywhere in the mouth, although they may be perceived at slightly different intensities at different sites which led way to the historical tongue map (whereby bitterness was tasted at the back of the tongue, sweetness on the tip and sourness/saltiness tasted on the two sides). These basic tastes only take us so far with evaluating coffee flavours. Coffee flavours run across the full spectrum from fruity, nutty, spicy, winy, floral, earthy, chocolate... the list goes on!