Such heritage breeds increasingly are capturing the imagination — and stomachs — of a new generation.

Heritage pork is nothing new. These breeds were popular before World War II, when pigs were raised outdoors on mixed-use farms. Because of the exercise they got and the fat they needed to get through winters outdoors, heritage breeds produced pork that was darker, meatier, more tender and more marbled than what is commonly available today.

Ignacio Mattos, chef at New York City's Il Buco, is one of the new wave going whole hog with more unusual breeds. He uses Tamworth for his specialty porchetta alla Romana and dried Italian sausages, or salumi. And he occasionally cooks with a rare breed of once-feral pig from Georgia's Ossabaw Island.

"You get a totally different product depending on the animal you use," he says.

The darker, redder, wilder meat from an Ossabaw pig imparts an intensity to his salumi that he can't get any other way. On the other hand, when he roasts the well-marbled Tamworth, pockets of sweet fat make the meat creamy as custard.