I pride myself on being a child of Hanoi, but only after nearly 20 years, did I realize that trứng vịt lộn is not exactly an authentic topping in Hanoi-style bún riêu.
With 2024 coming to an end, many apps are urging me to reflect on my year and Top 10 this and Top 10 that. If I were to make a list of the most surprising discoveries I've made this year, finding out that traditional “authentic” bún riêu doesn’t include trứng vịt lộn would definitely comes out on top. Turns out, my regular bún riêu order, one I’m always chanting like a mantra of a Hanoian craving — “riêu sụn giò tóp mỡ trứng vịt lộn, bỏ cùng nước” (bún riêu with pork cartilage, giò, with fried pork fat and balut egg) — is a modernized, non-traditional version of bún riêu. The diversity of toppings today is a far cry compared to the original simplicity of Hanoian bún riêu, which is a simple noodle dish that only highlights riêu cua (crab paste), an easy-to-find ingredient in the subsidy period in the early 1980s. Since then, I have always wondered: how could trứng vịt lộn become such an iconic dish of Hanoian cuisine?
From a rustic beginning
Trứng vịt lộn, or balut, is a fertilized duck embryo that can be enjoyed in numerous ways depending on the region and country. The English term “balut” originates from the Tagalog phrase “balut sa puti,” which means “wrapped in white.” This came from the traditional preparation method where the egg is “wrapped” during incubation. There are many ways the Vietnamese culture has attempted to make sense of its Vietnamese name.
Trứng vịt — or hột vịt, as it's commonly called in southern Vietnam — can be directly translated to duck eggs, but “lộn” has many interpretations, from official dictionary definitions to folk stories. According to the Vietnamese-Portuguese-Latin dictionary by Alexandre de Rhodes, “lộn” is a Nôm word of Vietnamese origin, meaning reincarnation. However, according to the writer Minh Lê, a folk tale references “lộn” as “mistake,” as in “This already half-hatched egg is mistakenly cooked!” Another version suggests that “lộn” can mean “mixed” due to duck eggs being incubated by hens, resulting in a mix-up. These myths all partially illustrate the prevalence of trứng vịt lộn in Vietnam folk life. However, its exact origins are somewhat unclear. Still, according to historical texts, the tradition of consuming fertilized eggs is believed to have originated in China and was imported into the Philippines through Chinese traders.
Before electricity, Vietnamese were used to trứng vịt lộn vendors lit up with oil lamps. Photo via Phụ Nữ.
According to an article in the Journal of Ethnic Foods, fertilized duck eggs are a shared delicacy of numerous Asian countries, including the Philippines, Vietnam, Laos, and Thailand. This practice began as a way to extend the shelf life of eggs before refrigeration was available, creating 毛鸡蛋, or “feathered egg,” which still have visible feathers once cooked. The fundamental difference between these regional baluts lies in the incubation duration: in Cambodia, the incubation lasts from 18 to 20 days, while Vietnamese eggs are usually incubated for 19–21 days to ensure the embryo is firm when cooked.
In Vietnam, the earliest historical mention of trứng vịt lộn can be traced back to the imperial eras of the Nguyễn Dynasty. In 1822, the Minh Mạng court hosted John Crawfurd, a British ambassador, at a banquet that featured three bowls of balut. If true, this shows that trứng lộn has been eaten in Huế since at least the 1820s, though there are no records indicating whether they were chicken or duck eggs. In his journal, Crawfurd described the balut as “the highlight of every grand feast.”
John Crawfurd’s Journal of an Embassy from the Governor-General of India to the Courts of Siam and Cochin China, a classic reference text of 19th-century Vietnam. Photo via Biblioasia.
According to writer Nguyễn Gia Việt, trứng vịt lộn was brought to southern Vietnam by the Ma Ní people (Manileños), which refers to Filipino soldiers who served as mercenaries for the French. Then, it was commercialized by the Chinese as the first seller in Saigon's Chợ Lớn. While the exact year is unclear, this was the first place to trade trứng vịt lộn, with Bến Bình Đông being a hub for duck egg incubation. The selection of duck eggs over chicken eggs is due to the former's stronger shell and membrane, with a smoother shell texture. This gives the egg stronger resistance during the demanding incubation process.
In the 1950s, Pateros was the “Balut capital” of the Philippines with around 400,000 ducks dedicated to balut egg production. Photo via History Oasis.
Vietnamese mostly enjoy trứng vịt lộn già, or old balut, which is incubated for 20–21 days. At this time, the embryos are small but most of the parts of the ducklings’ bodies have been developed, giving the otherwise soft albumen a more textured filling. Apart from trứng vịt lộn, trứng cút lộn (fertilized quail egg) is also a well-beloved street food often sold at nhậu restaurants, either stir-fried in tamarind sauce or fried with butter.
To a familiar daily presence
Trứng vịt lộn has many “faces” as it can be featured in numerous dishes. While any Hanoian child is familiar with the simple boiled egg, served with rau răm, the traditional Saigon way to eat vịt lộn is slightly more refined. The egg is put on a tiny ceramic cup, with the bigger end facing upward; the diner uses a teaspoon to crack a hole just big enough to slowly scoop the insides out to eat — similar to the way the French eat soft-boiled eggs (œufs à la coque). In southwestern provinces, trứng vịt lộn can be boiled in coconut water, infusing the signature sweetness of this distinctly southern flavor. Trứng vịt lộn can also lend itself brilliantly to other dishes, including hotpot, porridge, and soup.
Trứng vịt lộn and porridge and in trứng vịt lộn om bầu. Photo via Kênh 14 and Kenvin Travel.
In my daily life, I encounter trứng vịt lộn quite often: on my way home from work, I can count over 15 trứng vịt lộn spots only from fleeting observation. On any street, from cities to the countryside, right beside the foot of a skyscraper, or deep inside small alleys — you can always find a little vendor selling trứng vịt lộn, with tiny chairs here and there filled with diners wearing all types of outfit. White-collar workers in formal shirts? Grandmas wearing their signature patterned pajamas? Dressed-up ladies preparing for a girl’s night? Little kids still wearing school bags? Trứng vịt lộn is literally everywhere, every time, for everyone.
Therefore, if you love trứng vịt lộn, it will take only 5 minutes to find the nearest trứng vịt lộn, be it in a supermarket or at a vendor on the street. Boil for around 15 minutes and be creative with how you eat it: dipped in salt, pepper, and lime; with pickles; or with accompanying porridge. In my opinion, trứng vịt lộn contains the essence of Vietnamese cuisine: flexible adaptations, on-the-go convenience, and, of course, booming bursts of flavors packed in little vessels.
The nutritious trứng vịt lộn stew with mugwort and Chinese medicines, the best friend of all sick northern children. Photo via Check in Vietnam.
There are different reasons for eating trứng vịt lộn. For me, it is simply a sudden craving for it, often in the middle of meetings, work, and brain freezes. For my mom and grandmother, it is reserved for when younger members of the family catch a cold, as northerners often treat trứng vịt lộn as a nutritious comfort food. In fact, trứng vịt lộn is often deemed to be too nutritious, so my mom and granny tame this finicky treat by stewing it with ngải cứu (mugwort) and herbal ingredients like wolfberry, jujube, and longan.
According to common folk beliefs, eating trứng vịt lộn is also a way to dispel bad luck as “lộn” can also mean reverse. Just remember to eat an odd number of eggs only, then crush the eggshell after eating. Psychologist Nguyễn Thị Đào Lưu explained that this is due to spiritual reasons. In challenging times, people look for something to rely on, making eating trứng vịt lộn a comforting cultural practice that provides not just nourishment, but also a sense of hope.
And to a symbol of Vietnam's ever-evolving cuisine and identity
I pride myself as a connoisseur of Hanoian food, having spent my childhood inside the Old Quarter, and then growing up in Đống Đa — which arguably has the second-most vibrant food scene in the city, after Hoàn Kiếm. It has always been the norm for me to have bún riêu with trứng vịt lộn; the colorfully marbled egg elevates an already-perfect dish. Its saltiness blends harmoniously with the crab-infused broth, golden fried tofu, chili vinegar, raw vegetables, and shrimp paste. While some prefer having trứng vịt lộn in a separate bowl, carving out a piece to accompany spoonfuls of bún here and there, I reckon dropping the egg fully in the bowl gives the trứng vịt lộn broth a chance to shine. It brings out the full flavor profile of the egg: umami, gamy, and savory — exactly why Vietnamese all fall in love with it.
The vibrant full-topping bún riêu with trứng vịt lộn. Photo via Dân Trí.
Thus, when I learned that the authentic Hanoian bún riêu doesn’t feature trứng vịt lộn, I was in denial. Sure, there are “minimalistic” spots that do not serve the egg, but I have always assumed that this was merely a matter of topping preferences, similar to fried doughnuts in phở, which my family doesn’t fancy but are staples for many. Upon further reflection, it makes sense that the favorite bún riêu vendor of my dad, a true Hanoian, doesn’t serve trứng vịt lộn. Nestled deep inside a tiny alley that can barely fit my dad’s cruiser bike, the little vendor offers minimal toppings of just tofu and crab. One time, the owner grimaced at my request for trứng vịt lộn, exclaiming that her place, which has been passed down through generations, has never, and will not, serve that topping. It is obvious that the owner certainly did not approve of the modern version of bún riêu with trứng vịt lộn.
Nonetheless, to me, the modern bún riêu remains quintessentially Hanoian. Whether served with vibrant toppings or in its original minimalist style, each bowl still tells stories of Hanoi and its people, albeit, slightly different for each era. It doesn't matter whether it comes with vịt lộn or not, bún riêu is still enjoyed with friends, sharing stories, and keeping the heart of Hanoian culture alive. Hanoi's tradition of enjoying bún riêu during Tết as a refreshment from repetitive Tết dishes was continued even with the new addition of trứng vịt lộn. Sidewalks are lined with numerous vendors, serving people of all generations and even foreign visitors. It perfectly demonstrates how the non-traditional trứng vịt lộn is becoming a part of Hanoi’s gastronomic traditions, continuing and evolving the heritage.
Bún riêu for Tết is modern Hanoian tradition. Photos via Kênh 14.
Trứng vịt lộn, as non-traditional as it is in bún riêu, has become a part of the collective memories of the present generation, or even the older Hanoians who are willing to embrace changes. My dad was introduced to trứng vịt lộn in bún riêu by me, and sometimes — when hunger strikes — he will go for an “energized” bún riêu with trứng vịt lộn. Somehow, trứng vịt lộn not only brought a new flavor profile to a timeless dish but also renewed a culinary experience savored across generations. On my days of wandering around Saigon, I still miss my trứng vịt lộn–bún riêu, my mind filled with homesickness and nostalgia, longing to be back to my beloved city and its streetside vendors.
