Abstract: The present invention provides a method of decaffeinating green coffee beans without adversely affecting their acidity or the flavor of coffee beverages produced from them. The invention also relates to a method useful with supercritical decaffeination, in particular with caffeine extraction using supercritical carbon dioxide. In accordance with the invention, green coffee beans are subjected to a treatment by contacting them with an acidic fluid containing an organic acid that is not soluble in supercritical carbon dioxide, preferably an aqueous citric acid solution, prior to or simultaneously with decaffeination.