What does Rioy mean in coffee?

Rioy is a term used in coffee trading - particularly in Brazil - to describe a distinctive, medicinal, iodine-like, or phenolic off-flavour. It's associated with over-maturation on the branch or enzymatic activity in over-dried cherries, producing specific chemical compounds that give the cup an unmistakable and highly undesirable character.

The name is thought to derive from the Rio de Janeiro region of Brazil, where this flavour profile was historically associated with lower-quality lots. In cupping, a Rioy note is one of the most recognisable defect flavours - an almost disinfectant-like quality that stands out clearly even at low intensity, and makes a lot essentially unsellable to specialty buyers.

Rioy is caused by phenolic compounds including guaiacol that develop when cherries experience unusual enzyme activity during overripe or poorly managed drying. It's counted as a primary cup defect and grounds for downgrading or outright rejection.