Ding'an Zongzi

Ding'an zongzi is made in Ding'an county in the interior of Hainan and is reckoned one of the island's famous zongzi. Its identity rests on local ingredients: glutinous rice and salted duck eggs from the county (the eggs cured in local red clay), Ding'an black pork, and 柊叶 leaves gathered from the county's volcanic-soil areas, used in place of bamboo leaf. In March 2014 the Ding'an Zongzi Association registered 'Ding'an zongzi' (定安粽子) as a national geographical-indication certification trademark through China's trademark office, making it one of the earliest Hainan foods to hold such status. Local accounts say the zongzi goes back several hundred years and call it 'Hainan's first zongzi,' but a precise founding date is not documented; what is documented is the geographical indication and the protected ingredient and method standards behind it.

Unwrapped from the dark 柊叶, the rice is a single soft, glossy, faintly leaf-scented mass, holding its pyramid shape but yielding at once to a spoon — never the firm, separate grains of an under-boiled zongzi. The first taste is the savor of pork fat soaked through the rice; in the center, a layer of slow-cooked black pork that is meltingly tender, and a whole salted egg yolk gone rich, oily, and sandy. Done well, the rice is uniformly soft to the very core and the fat has melted into it so the whole thing is oily-savory without being greasy; done badly, the heart of the zongzi is still chalky and hard because the boil was cut short, or the yolk is dry and the pork stringy.

The very long boil is the point. A big, tightly wrapped zongzi heats slowly from the outside in, and only hours of simmering bring the dense core of glutinous rice to full gelatinization — its starch (rich in amylopectin) absorbs water and swells into the soft, sticky, translucent mass that defines a good zongzi, while an under-boiled center stays chalky. Over the same twelve-or-so hours the fat in the fatty-lean black pork renders and is driven into the surrounding rice, carrying salt and savor through it, and the pork's collagen breaks down to gelatin so the meat turns spoon-tender. The salted yolk, already cured firm and oily by salting (which draws out water and sets its proteins and fats), holds its shape and turns sandy and rich in the middle. The 柊叶 wrapper does two jobs: it seals the parcel so it cooks as one dense mass and lends a faint herbaceous aroma to the rice, the role bamboo leaf plays elsewhere.