Gordon Ramsay's softer side comes out when the formidable chef presides over aspiring kid cooks on a new US reality show.

Youngsters from eight and 13 who love to work in the kitchen will face off on MasterChef Junior, showing from September 27 on Fox.

Ramsay, the expletive-spewing restaurateur and star of such Fox shows as Kitchen Nightmares and Hell's Kitchen. The new show is based on the popular British MasterChef series.

"I don't think I swore once," Ramsay told the Television Critics Association in Beverly Hills.

"Twice," corrected Gavin, a 10-year-old contestant from San Francisco, adding that Ramsay's cursing was directed at servers during a restaurant challenge, not the kids.

"We know the F-word means food," Ramsay said.

The contestants knew of Ramsay's fiery reputation as a demanding taskmaster, but nine-year-old Sarah, from Pacific Palisades, California, said: "He can't be really mean because we're kids."

Ramsay, who has three daughters and a son, told the budding chefs when their food was not good enough.

"I'm brutally honest and I think the kids appreciate that," he said. "Being firm and fair isn't anything we can be short on."

To soften the blow, they were sent home in pairs during eliminations.

"We hate saying goodbye," Ramsay said. "We let them down gently."

Tommy, an 11-year-old contestant from Palos Verdes Estates, California, said, "He was giving us tips on making it better."

Gavin added: "He taught you not to give up and keep on trying."

Several of the seven kids at the TCA panel said they hope to pursue careers in food when they grow up. Ramsay said he enjoyed mentoring the children and teaching them life-long skills about eating healthy food.

"Learning to cook for yourself is so important to set them up for the rest of their lives," he said.

Joining Ramsay on the judging panel are restaurateur Joe Bastianich and chef Graham Elliot.

The first audition round features 24 children split into three groups of eight to create seafood, pasta or desserts.

The top 12 finalists earn a white apron and advance to a series of challenges and cook-offs, including preparing beef Wellington as a tag-team. They take over a fine dining restaurant in Los Angeles to prepare a three-course meal.

The eventual winner earns 100,000 dollars.