The habanero pepper is one of the hottest varieties of chili peppers. This chili pepper measures from 100,000 to 500,000 Scoville units compared with a jalapeno pepper, which measures 5,000 to 15,000 Scoville units. The Scoville unit of measure is directly related to a chemical called capsaicin. The higher the number of Scoville units, the greater the concentration of capsaicin.