Mr. Bosland claims to have broken the two million Scoville mark in February 2012 with his Trinidad Moruga Scorpion.

WSJ: Arms Race to Grow World's Hottest Pepper Goes Nuclear

But Mr. Scott, one of the few people on Earth who has tasted both varieties, says the Moruga Scorpion is clearly hotter.

WSJ: Arms Race to Grow World's Hottest Pepper Goes Nuclear