Mammoth jalapeno peppers contain capsaicin, the chemical that provides the heat of hot peppers. In fact, the genus name Capsicum comes from the Greek word "kapto," which means "bite." Mammoth jalapeno peppers have a Scoville rating of 3,500 to 4,500, but the heat of jalapeno pepper varieties range from 2,000 to 8,000 Scoville units.