Quaker

Quaker: A defective coffee bean that fails to roast properly, remaining significantly lighter or pale-colored compared to the surrounding roasted batch. Quakers are caused by underripe cherries, improper harvesting, or a lack of internal sugars and starches, which prevents the Maillard reaction and caramelization from occurring during roasting. They impart an unpleasant papery, peanutty, or cardboard flavor to the cup and are considered a major quality defect in specialty coffee.