A curled leaf, pale at its broken edge, can persuade the eye before the cup is brewed. Fraud begins there. Color, aroma, and bitterness register surface cues, while drying, storage, age, and batch variation can alter those cues in genuine material as readily as in a fake. Resemblance is cheap. Chemical identity is not.The old bedside test is worse than incomplete: it can reward a product dyed, per...More