The air conditioning was on in the Food Science and Technology lab at the National University of Singapore when Yuyun Lu, a tall, thin doctoral student from China, met us at the door.
Sweaty after the hot, humid walk across campus, I shivered. I was also eager to taste my first sample of durian wine.
Lu left to get the wine. Overhead, industrial lights hummed.
He returned carrying a tray with three sparkling wine glasses and two translucent plastic bottles filled with a pale, yellow liquid. In the sterile lab setting, the glasses looked so out of place that a smile stole across my face.
While Westerners often object to the scent of durian, a Southeast Asian fruit that regularly sends security personnel searching for gas leaks (a Melbourne hospital was the site of a recent debacle), most people in Singapore find the aroma appealing. Finding out why durian wine doesn’t smell like durian fruit is the focus of Lu’s doctoral research.
As Lu poured, I inhaled deeply, searching for the sudden burst of sulfur I expected to waft from the bottle. I noted only whiteboard markers and, possibly, burnt toast.
“The reported adverse effects of human ingestion of durian and alcohol include cardiac episodes and even death,” Lu said, calmly sipping his wine.
The complex flavor of durian is shaped by more than 200 volatile aromas, including the same esters that give rum and pineapples their tropical sweetness, and sulfur compounds also found in cocoa, roasted cabbage and rotting eggs.
Durian aficionados describe the scent as sweet, with a hint of coffee or bitter chocolate and a slightly savory, herby bite. To please durian lovers, a wine made from the fruit should retain its contradiction of aromas.
The problem—or possible stroke of luck—is that the yeasts used to turn the fruit to alcohol also break down the sulfur compounds that give durian its famous, well, stench. I swirled my glass before cupping the rim around my nose. I smelled cookies, grass and only the faintest hint of green onion.
“As most of the sulfur compounds decrease to trace levels, we want to know where they go…or what they have changed to,” said Lu.
Lu is also balancing flavor with safety, because he believes that two specific sulfur compounds are responsible for a centuries-old taboo against consuming durian and alcohol together. A 2009 study by Japanese researchers found that durian’s famed garlicky-garbage aroma comes from sulfides that also inhibit an alcohol-metabolizing enzyme.
“The reported adverse effects of human ingestion of durian and alcohol simultaneously include cardiac arrest episodes and even death,” Lu said, calmly sipping his wine.
I daringly sipped mine, too. It was buttery and fresh; a light white wine. The potential dawned on me.
If Lu can exclude those specific sulfur compounds, durian wine may ultimately be more delicious (and safer) than the fruit itself.