On the day of writing this article (August 26, 2019), Carolina Reaper holds the title of the hottest pepper in the world. In order to present which pepper is the sharpest in the world based on a measurable value, we need to explore a bit of theory. The sharpness of peppers is given using a special scale called the Scoville Heat Unit (SHU). The SHU unit is a way of giving a measurable scale of the capsaicin concentration in a pepper. Capsaicin is the chemical responsible for the sharpness of peppers.
Carolina Reaper scored 2,200,000 (two million two hundred thousand) points on the Scoville scale. For comparison, this result makes it about 200 times hotter than Jalapeno peppers (11,000 SHU). The second most spicy pepper in the world is Trinidad Moruga Scorpion with a score of approximately 2,000,000 (two million) SHU.