How big could the market be for a pepper so hot it leaves some customers in pain?

Bigger than you might guess.

Though they remain a novelty in the produce aisle, ghost peppers enjoy a steady demand that’s edging upward, said Pete Aiello, co-owner of Gilroy, Calif.-based Uesugi Farms.

The ghost pepper weighs in at more than 1 million units on the Scoville heat index. By comparison jalapenos are child’s play, twiddling their thumbs in the 2,500 to 8,000 range. It was named the hottest pepper in the world by the Guinness Book of World Records in 2007, though other varieties have since surpassed it.

“The people who buy it are a different breed,” Aiello said. “They actually enjoy that level of heat. I’ve never eaten one myself.”

Maybe because he’s watched others eat ghost peppers grown by Uesugi Farms.

“If it’s a good seed and a good pepper with the correct amount of heat, it usually doesn’t turn out too well for the person who eats it,” he said. “I’ve heard people describe a feeling of air passages starting to swell and close. I see their faces turn from a nice rosy color to pale white. Sometimes there’s a look of panic in their eyes like, ‘I might need somebody to take me to a hospital.’”

For that reason most consumers down the peppers with a chaser, not straight.

“They’re making salsa or diluting it to get the heat down a bit,” Aiello said.

While a few hotter chilies now exist, he said, so far they lack the market reach of ghost peppers.

“A lot of purchasers are foodie types who buy this just to tell everybody they got the hottest pepper,” Aiello said. “These are mostly individuals at home who have watched the cooking shows and want something with some heat in it. It’s still an extreme novelty.”

“It hasn’t gone mainstream, but the market is growing a little each day. We have not even a fraction of the product to keep up with the demand. Usually it’s sold before we even pick it. Then buyers have to wait a week or so for more to be picked.”

While ghost peppers sell well in stereotypical foodie locales like the San Francisco Bay Area, most of the retail buyers are in the Midwest.

Uesugi Farms ships ghost peppers dry in half-pint clamshells, 12 per case. The company started growing them in 2009 with a trial of 50 to 100 plants. The year after, they moved indoors to a Salinas operation run by Castroville, Calif.-based Golden Field Greenhouses.

Other sources for ghost peppers include San Antonio-based Alamo City Pepper Products.

A plentiful supply at Uesugi is still two to three years away, Aiello said, as issues with consistency linger.

“The seed is not commercially available just yet,” he said. “For now we’re sourcing it like any backyard grower would, finding it on the Internet and buying it in small quantities at expensive prices. Some is hot and some has no heat whatsoever. We’re struggling to weed that out. And it’s an open pollinator, which is also an issue. It’ll cross-pollinate with pretty much any nearby crop.”

The distress some report on biting into a ghost pepper prompted the grower-shipper to print “Caution – Eat with Care” on clamshell labels.

Uesugi Farms’ product line includes bell peppers, various chilies, napa cabbage, sweet corn, strawberries and pumpkins. “Ghost peppers are the only wacky thing we do,” Aiello said.