It is the aftertaste. What the taste is after the brew is drunk and the time it lingers. It is a product of body and acidity. This is how resonance got associated with a taste because as you strike an object like a glass or piano string, it rings for a while after you strike it. This term relates to a specific bean.
Mexican beans have a particular character to their taste.
Java has a characteristic taste. Mocha has a characteristic taste. Palate, aroma, and tactility all make up a characteristic taste. Additionally, the degree of roast makes up a characteristic taste. When a person states this coffee drinks has character, they really are not saying much.