The Scoville scale is a tool for measuring the spiciness of chili peppers. US pharmacist Wilbur Scoville, who invented the scale in 1912, measured the pepper’s spiciness by taste. He put an extract (提取物) of the capsaicin oil from a pepper into a solution (溶液) of sugar water and placed it onto the tongues of taste testers. The amount of water needed to wash away the spiciness was recorded. Each chili could then be given a number to score its spiciness, which forms the Scoville scale.