ISO 6668:2008 specifies a method for the roasting of green coffee, grinding the roasted coffee, and the preparation — from the ground coffee — of a beverage to be used in sensory analysis. The sensory analysis carried out following this preparation may be used to determine the acceptance or rejection of a shipment of coffee, subject to agreement between the parties concerned. Generally, the sample will require a light roast for assessment of defects, and a medium roast for assessment of flavour and colour. A beverage prepared in accordance with ISO 6668:2008 can be used not only for purposes of quality control, but also for purposes of comparative assessment of different samples, in which case an identical procedure can be followed for each of the samples.