The Book of World Records say the world's hottest pepper is the Carolina Reaper grown in South Carolina.
The pepper was grown by Ed Currie from PuckerButt Pepper Co. and measures in at an average of 1.5 million on the Scoville chart. The hottest chili in the batch was clocked at 2.2 million, for some perspective, standard issue pepper spray rocks in at around 2 million Scoville Units.
The Carolina Reaper beat the previous title holder the Trinidad Moruga Scorpion by around 300,000 Scovilles.
The National Post have an interview with the man behind the pepper.