A former coworker called me to playfully nag me about my previous plan to visit Hanoi: “Are you waiting for all the sấu to drop before making a move?”
“Is it sấu season already?” I replied. It’s been nearly a year since I was last under the sweltering capital sky, strolling past shadow-streaked yellow walls, and huddling in a corner cafe with a view towards a summer-drenched street. Summer arrives in the city sporadically, sometimes at a sleepy speed, but occasionally as hurriedly as the way the rows of sấu trees on Phan Đình Phùng and Trần Phú bear fruits.
Generations of Hanoi’s children and anyone who happens to be in town during the season can’t help being enamored by this homely but unique fruit. With summer comes the sấu season, bringing about clusters of plump fruits alongside the chorus of cicada buzz. They start showing up everywhere, from family meals and sidewalk beverages to memories frolicking beside snack vendors. Sấu is not merely a fruit, it’s part of the cultural tapestry of a distinct and elegant Hanoi.
Beauty is in the eye of the beholder
Once I was tricked into believing a rather facetious explanation of sấu’s name: because the fruit is so sour, when one gives it a taste, their face will crumple into a “xấu” grimace — “xấu” is ugly in Vietnamese. I’ve since learned that the fruit’s name might derive from the Nôm character 瘦, meaning “gaunt.” It’s likely that the name is also used to describe the facial expression one subconsciously sports when tasting sour food.
The scientific name of sấu is Dracontomelon duperreanum, but it’s also known colloquially as sấu tía or long cóc. Sấu a species of drupe, produces clusters of fruits that are spherical, spanning around 2 centimeters. The flesh is white and crunchy, surrounding one hard seed. Sấu is juicy but sour when young; as the fruit ripens, it turns yellow and fragrant. Sấu is a woody plant, with wide canopies and a long life span reaching up to 10 centuries. It thrives in alluvium-rich soil of temperate, hilly regions with the average temperature ranging 20–25°C. Sấu is commonly found across Northern Vietnam and high-altitude Central Vietnam.
Beneath the rough skin, sấu contains many beneficial nutrients. According to traditional Vietnamese medicine, sấu is an ingredient for coughing and sore throat remedies, etc. The sourness promotes digestion and reduces nausea.
Sấu’s abundance and unique flavor understandably lead to its widespread appearance in northern cuisines. Once you’ve tried it, it’s hard to forget, like an intense first crush, encompassing all the longing and anticipation of a new summer and its resulting sấu harvest.
A mainstay on Hanoi streets
Ambling along Lê Phụng Hiểu and Lê Thánh Tôn streets in the historic areas of Hanoi, and new thoroughfares to the west of the city like Dương Đình Nghệ and Phạm Văn Bạch, pedestrians will enjoy the cooling shade of rows of luxuriant sấu trees.
A new season of minuscule sấu blossoms has begun. They look like tiny white bells on the branches, giving off a gentle scent, both pure and relaxing to heave in a lungful. Oh and how delicate are sấu blossoms! With every light breeze that can barely shake the branches, a light blanket of petite flowers will scatter on the busy pavements, on passersby’s shirts and hats.
“Just merely flowers days ago
Once gushing with passionate smell
It only takes a budding of doubt
for the fruits to be born for real.”
— ‘The young sấu up high’ (Quả sấu non trên cao), Xuân Diệu
Like Xuân Diệu’s stanza describes, bunches of baby sấu materialize as quickly as summer arrives, dotting the tree with emerald green marbles. In a few days, fruit pickers will show up, and then mobile vendors will start ferrying bamboo trays filled with piles of green sấu across town.
The first mention of sấu appeared during the Nguyễn Dynasty, in Đại Nam nhất thống chí (Đại Nam Comprehensive Encyclopaedia). At the time, residents of Bất Bạt District (Ba Vì today) and Mỹ Lương District (Chương Mỹ today) widely cultivated sấu and trán đen (Canarium tramdenum), the former for eating fresh while the latter were used to press for oil.
In 1883, Resident-Superior Jean Thomas Raoul Bonnal ordered a makeover of the Hoàn Kiếm and Ba Đình areas, imposing a guideline on which species to plant. The trees must have vertical trunks, tap roots to minimize being toppled over by strong winds, expansive canopies to shield streets from the sun, no toxic sap or unpleasant scents. Sấu satisfied every requirement.
In the first decade of the 20th century, streets from the south of Sword Lake to the western side of the city were outfitted with sấu trees. According to statistics from the Hanoi Park Company, during the subsidy period, sấu made up as much as one-third of all public trees in Hai Bà Trưng, Đống Đa, Ba Đình and Hoàn Kiếm districts. Another data set shows that, in 2017, out of 334 trees on Hai Bà Trưng Street, 86 were sấu.
The soul of Hanoi’s snack scene
It’s unclear when sấu started entering the Vietnamese culinary landscape, but historical documents show that even during the earliest times, locals used molasses to dry sấu and then simmered with sugar to produce candied fruits. During festive occasions, the fruit is also used to flavor chicken and duck, or pickled with salt to make condiments. Gradually, sấu has persisted over generations, in the minds and stomachs of foodies in the north.
For kids, the peppering of sấu blossoms signals a time when school seems like a distant memory and when the fun doesn’t stop. Children pluck the flowers from the ground and string them together to create jewelry for make-believe weddings. And then when the fruits are big enough, the trees become a rendezvous place for tree-climbing sessions to pick sấu to dip in salt, a hot commodity despite the sourness.
To home cooks, getting an ideal batch of sấu is like playing the lottery. Maybe you’ll bump into a vendor featuring freshly picked fruits straight from the branch, but sometimes, you’ll have to settle for harvests that have come in on trucks from surrounding provinces, especially Thái Nguyên. The result is a cooling bowl of vegetable broth with the tangy juice from several mashed sấu. A rustic northern meal is not complete without a plate of blanched greens, a bowl of crunchy pickled baby eggplants, and a big pot of tart sấu broth. These days, with a growing appetite for more substantial food, many new dishes have been created, like sấu-braised short ribs, caramelized shrimps with sấu, sấu braised duck, etc.
Once sấu abundance reaches its climax each summer, excess fruits are sequestered away in jars for pickling. The treatment is simple but effective in retaining the fruit’s natural texture and tempering its sourness. Candying is also a popular way to ensure that sấu is available for munching year-round. Mature sấu is sun-dried to remove extra water, then soaked with sugar, salt and ginger to make ô mai sấu. These nuggets also have an important place in the culture of Hanoi, enthralling eaters with their complex flavors of sourness, spiciness, sweetness, and saltiness, in addition to a soft inside and chewy exterior.
As the season comes to an end, sấu turn golden on the trees, taking on a distinctive sweetness that’s perfect to snack on with chili sauce or beef jerky. With every bite, your palate is inundated first by the heat of chili and the sweetness of the fruit, but then, a timid tartness lingers on the tongue. This fascinating flavor profile will keep you wanting more.
From rows of verdant trees along streets to rustic snacks of our childhood, sấu has become a true sliver of Hanoi heritage. Whenever I stop by a bún đậu eatery in Saigon, I always order a glass of sấu juice. Perhaps I’m compelled by my affection for sấu’s unique flavor, or by the inseparable connection between sấu and Hanoian culture. Sipping on the sweet-and-sour liquid, I feel as if I’m on the pavement of Hàng Khay, watching the capital’s traffic rush by.