One of my favorite lunches on earth is a plate of Cantonese roast meats served over rice. And my favorite part of that lunch is siew yoke, roast pork belly with layers of lambent fat, juicy meat, and skin that has bubbled and popped all over like Rice Krispies—hence the name crackling—to produce a puffed and crunchy counterpoint to the meat's succulent interior. In Singapore, where I live, Cantonese restaurants take pride in their siew yoke, and recently I've become somewhat obsessed with perfecting the dish myself.
I've always had a thing for roast pork. When I was growing up in London, my father would make a heavily seasoned version called babi panggang, a dish from my family's Peranakan heritage. Native to Peninsular Southeast Asia, the Peranakans are descended from Chinese immigrants who adopted local practices and often found wives from within Malay, Indonesian, and other surrounding communities. This mix of cultures gave rise to dishes like babi panggang—essentially a Chinese-style roast pork but with a unique fragrance from a judicious dose of freshly roasted and ground coriander seeds. My father would rub the skin of the pork with salt and vinegar to help it crackle, though he never explained why. Often it would work, but not always. The crackling was sometimes light and airy, sometimes hard, and sometimes impenetrable.
Over the years, I became fascinated with roast pork preparations from other cultures. Once, a Spanish cook showed me how she prepared cochinillo asado (roast suckling pig). She massaged it all over with salt, pepper, and fruity olive oil, then smeared its split underside with chopped garlic, onion, and thyme and sloshed some white wine and brandy over the skin to encourage it to color during roasting. The result: butter-soft meat and ears like crunchy nuggets of nirvana, but skin that was glossy and crisp and somewhat chewy. The same was true of an Indonesian babi guling (suckling pig) I once sampled, whose lemongrass- and pepper-spiced meat was clad in skin prettily gilded with turmeric but only intermittently crackled.
When I decided to perfect my own recipe for crackling-topped roast pork belly (see Recipe: Crispy Roast Pork), I knew I had to draw from those memories. Cantonese siew yoke was the kind I had eaten the most of, so I decided to start with that as a foundation. I approached Pung Lu Tin, a Chinese master chef and consultant at the Society of Chinese Cuisine Chefs of Singapore, who kindly let me pick his brain. First order of business: the marinade. The meat should be seasoned to improve its texture and flavor, but not so much as to steal the skin's thunder. "Five spice powder, salt, some sugar," Pung said. "And the original Cantonese roast pork uses some red fermented bean curd." Simple and plain, salt to season and firm the meat, spices for fragrant warmth, and a touch of funkiness from the bean curd, which is preserved with a special yeast and rice culture that gives the condiment a floral, misolike aroma and rosy maroon hue. It also tints the cooked meat—otherwise gray or off-white—an attractive pale pink. Apart from the marinade, said Pung, the other crucial points are "control of the fire, and the pricking of the skin."
For more on that, I visited Singapore's Mandarin Oriental Hotel to call on Wilson Goie, who holds the title of roasts chef and oversees a kitchen barely bigger than the traditional Chinese oven it houses. The nearly five-foot-high metal cylinder is centered on a clay vessel of burning charcoal in its base, and it exploits gravity: Meats hang from a rack, and they are self-basted by their fat as it melts. There is no temperature gauge; Goie uses his hands and 20 years of experience to assess the heat and control the roasting process.
Goie's recipe is old-school and minimalist. He rubs a six-and-a-half-pound slab of pork belly on its meat side with salt and other seasonings—which he coyly refused to divulge—and hangs it up for half an hour or so to allow the marinade to soak in. He then roasts it, meat side facing a medium fire, until it is about 70 percent cooked through; the heat cannot be too high during this phase, or the skin will lose too much moisture and later refuse to crackle properly. Then he removes the pork, pierces its skin all over with an instrument that looks like a wooden mortar with sharp metal prongs protruding from the end, rubs it with just a little salt, and hangs it up for an hour or two in a well-ventilated area. This cooling period, he told me, further promotes the subsequent blistering of the skin.
In a second round of roasting, Goie faced the skin inward over a fierce, flaring fire. Too low a heat produces what he calls "scorpion skin," tough and chewy—a result of the skin's moisture cooking off too gradually. A sufficiently intense fire turns pockets of moisture in the skin to steam, which expands explosively, creating tiny bubbles with walls of protein that crisp in the scorching heat. Goie let the skin roast until it built up a stratum of char, an assurance that the top layer had fully puffed. He pulled the pork out of the oven and scraped off the char with a blade, to reveal a sandy, golden layer of crunch. "If the skin is thick and not quite done, I do another round of charring and scraping," he explained.
Goie's method worked well when I adapted it for my home oven, but there remained a thin, sticky layer of unblistered skin between the crackling and the underlying fat. Dreading the oven scrubbing already hanging over my head, I didn't want to roast and scrape a second time. Also, while the lacy layer of crackling—Goie calls it song hua, which means something like melt-in-the-mouth—was beautiful, I wanted something crunchier, sturdier, more like a corn chip than a puffed cheese ball.
Then I recalled something Pung had said: "Some chefs apply things on the skin—salt, lime juice, baking soda, maltose—to make it more crispy." Acid, alkaline, and alcoholic ingredients all help to denature the skin proteins, disrupting their physical structure and loosening them up, which promotes blister formation and browning. From past failures, I knew that sugar, vinegar, and condiments like soy sauce gave me poor or patchy results, but recipes that used a rubdown of gan sui, or alkaline water, a solution of sodium and potassium carbonates, usually achieved a high degree of puff. But I didn't like the soapy, bitter aftertaste the gan sui left. I knew I would have to come up with another method.
As important as the crackling was finding the right cut of pork belly. I have learned from my butcher that the best pork belly for roasting is about one and a half to one and three-quarter inches thick, with evenly alternating strata of meat and fat. In Chinese this is called "five flower" pork, in reference to the number of layers—skin-fat-meat-fat-meat. The fat layer immediately under the skin should not be too thick; a few nubbins of rib-related cartilage in the outermost meat layer are perfectly acceptable. A four- to four-and-a-half-pound slab is a manageable size for a home oven, and the neater the slab's cut edges, the more even a shape it will retain during cooking.
To reap the benefits of an alkaline wash without soapiness, I ultimately settled on three steps to treat the skin. First, I decided to prick the raw pork skin, which would allow some alkali to seep in. I used the same nail-tipped Cantonese chef tool that Chef Goie had used. Second, a scald: holding the pork slab vertically over the sink, I used a measuring cup to stream a boiling-hot solution of baking soda and water over the pricked skin side only, to gently soften and denature it. Third, just before roasting, I brushed the skin with Chinese rose-scented rice wine. Its light acidity neutralizes any remaining soda traces, and its alcohol helps denature the skin proteins.
I laid the pork belly horizontally on a roasting rack fitted inside a roasting pan. In my oven, a slightly longer first roasting phase was required to render out the fat: 45 minutes as opposed to the 30 minutes needed in a restaurant oven. To streamline the process, I eliminated the drying phase between the roasting phases, and instead I marinated the meat overnight before cooking. For the second, skin-crackling roasting phase, I simply let the pork take as long as it needed for the skin to fully puff, and scraped off any charred spots as Chef Goie did.
The first attempt went passably well. A few more experiments taught me: you can use either the regular oven function or the broiler for the second roasting phase; a fan-assisted oven speeds up cooking times; and paper towels can mop up any excess rendered fat that pools on the skin.
Now superlative crackling and succulent meat are at last within my grasp as a cook; I can, consistently, re-create the best of my roast pork experiences, without fear of leathery skin or any other shortcomings that might get in the way of a wholly satisfying meal.