Acidity is most easily understood in relation to certain fruit flavours. Think of the sharp and tangy sensation when you bite into a citrus fruit. Coffee contains similar acids and upon roasting, they affect the overall flavour and aroma in the cup. Acidity in coffee can be identified as lively, bright, or sparkling, all of which suggest different levels of intensity.
When we cup, we are drawn to acidity that adds a degree of character to the flavour profile. Distinctive but never off-putting, the acidity complements the other tasting notes and it usually equates to a juicy and pleasurable taste experience.