Chicken and pork skins are most commonly used, possibly because they are the most familiar. Gribenes, the byproduct of rendering chicken fat (schmaltz) from the skin is a familiar dish in the Jewish kitchen. London Grill in Fairmount has been serving gribenes - as well as chicken skins on dishes like nachos - around the Jewish holidays for years.
"My grandmother would give us gribenes as a snack," says Supper chef/owner Mitch Prensky. "Little crunchy, salty things . . . they've got a very concentrated chicken flavor."
Taking inspiration from his bubbe, with a little Southern style tossed in, he uses chicken skins in the green salad on Supper's menu. His smoked chicken cracklings add a croutonlike texture to buttery greens, apples, corn bread, and a buttermilk dressing. "Chicken skin is like bacon for those who don't eat pork," says Prensky.
In the South, pork skin with the fat rendered out is commonly known as cracklings. In Latin American cuisine, double-fried into light-as-air puffs, it's called chicharrón.
At the Italian eatery Amis, chef Brad Spence offers the "Beast of Amis" dinner starring a different protein every week - from soft shell crab to veal - and usually includes skin. Recently, a roasted pork shoulder was presented with a salad of spicy greens, fresh cherries, and fried pork skin.
But the pig hide can have more than just a date with a deep fryer. At Russet, chef Wood also looks to Italy for inspiration. He makes a Northern Italian sausage called cotechino by grinding the skin into the meat mixture. It is then boiled, charred on the grill, and served with a tomato bread salad.
"When you have a pig you have a surplus of skin," says Wood. "It makes the sausage snappy." He also simmers skin with beans, and then purees part of the mixture, which gives the beans - used in dishes such as bean stew or cassoulet - a creamy texture.
The trend extends to the sea. The skin of some fish, when cooked at a very low temperature, turns as crisp as a potato chip. Chip Roman, chef and owner of Mica in Chestnut Hill, serves cool and fatty salmon tartare on crackerlike salmon skin to diners as a welcoming snack.
"It's a way to utilize everything," says Roman. "But all skin is not created equal. Some are really tough."
The skin of the arctic char also turns brittle. Chef Greg Vernick dries and fries the outer layer to serve with the flesh of the fish and chili oil at his new eponymous Rittenhouse eatery.
"When you eat the dish as a whole it has a cool mouthfeel because you've got the fatty fish and the crispy skin," says Vernick. "Most chefs like that salty, briny, crispy flavor profile. Skin is a great vehicle for that."
Whether chefs use chicken, pork, duck, or goose skin, removing all the moisture by slow cooking is a necessary step to get the desired texture. As with gribenes, that often involves rendering out the fat, which chefs use in other dishes, such as the goose sausage that Wood makes at Russet.
Getting that salty crunch can take an extraordinary amount of work. At Rittenhouse Tavern, chef Nicholas Elmi (formerly of Le Bec Fin) uses cracklings in lieu of prosciutto on a Gulf shrimp pavé, summer melon, and Saba vinegar salad. He rinses the pork skin for about six hours to remove impurities, soaks it in an ice bath for 24 hours, cures it in aromatics, salt, and sugar for a day, braises it in pork stock, then dehydrates it in a low-temp oven overnight.The skin then is deep-fried to puff up and dusted with powdered Worcestershire. "The curing imparts flavor," says Elmi. "Usually they taste just like fried air."
Getting the right texture is vital for the menu sell. "Philadelphians are game," says Wood. "If it's in a sausage people can wrap their heads around it. If it's crispy people can wrap their heads around it. If I served a plate of boiled skins people would have a harder time," he says. "That's the art of cooking."