Phở Before Phở: Following the Broth Back Through History

2. Broth – nước dùng

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Pot-au-feu and the Broth of Phở

Pot-au-feu is prepared by slowly simmering beefbones with onions, carrots, celery, thyme, turnips, and potatoes—a method thatappears remarkably similar to the way phở broth is made.

The key differences, however, lie in thearomatic foundation. Phở does not include potatoes or celery;and western spicelike thyme, mustard seed and parsley, instead, drawing from a long-standing Vietnamese and Southeast Asian spice tradition, its broth is built around warm, fragrant spices such ascinnamon, star anise, and ginger, creating a distinctly local aromaticprofile.

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Sá sùng – a distinctive Vietnamese umami source

Most notably, Vietnamese cooking has long included an ingredient that is not rare,yet rarely used in other culinary traditions:

Sá sùng— also known as peanut worm — aliteral umami bomb.

Once harvested, sá sùng is sun-dried immediately on site, apractice that preserves freshness and results in a product of exceptionallyhigh quality. This method is closely tied to tropical coastal environments, where strong, consistentsunlight allows natural drying to take place year-round.

During this natural aging process—much like the aging of steak or other meats—endogenousenzymes break down proteins, concentrating amino acids that areresponsible for umami and depth of flavor, particularly:

·        Glutamicacid → deep, rounded savory sweetness (similar to natural MSG)

·        Glycine& Alanine → lingering sweetness and meaty notes

·        Asparticacid → enhanced depth and complexity

Additionally, dried marine products contribute a distinctive “oceanic” character,a subtle yet unmistakable sense of the sea that adds further dimension to thebroth.

Today, the technology behind highly concentrated powdered MSG has become extremely advanced. As a result, natural umami ingredients that are both traditional and expensive—such as peanut worm (sá sùng)—are no longer widely used. The price of dried peanut worm is now nearly ten times higher than that of fresh beef by weight.

For this reason, peanut worm is most commonly found in home-cooked pots of phở, where cost efficiency is not a primary concern. In commercial phở operations, which require a stable supply chain and clear profit margins, few vendors are willing to use it. Used generously, it drives costs too high; used sparingly, it fails to create a perceptible difference in flavor.

However, for phở kitchens committed to a purely natural flavor philosophy, peanut worm remains indispensable, contributing depth, natural sweetness, and a lingering umami finish to the broth.

Xáo Trâu – a pre-existing Vietnamese predecessor

As mentioned earlier, long before the concept of pot-au-feu was known in Vietnam,local culinary traditions—particularly in NamĐịnh Province—already featured a dish known as Xáo Trâu, often regarded as a direct predecessor of phở.

Rather than beef, this version traditionallyused water buffalo meat, apractice that still survives today in certain regions where phở made with buffalo remains common.

Xáo trâu consists of rice noodles served with stir-fried buffalo meat, often stir-friedwith star fruit (khế) andaromatics, including onions and ginger,elements that are still recognizable in phở today.

Unlike modern phở, however, xáo trâu was not tied exclusively to rice noodles.Depending on household preference, it could be eaten with rice noodles, bún, or even plain rice,reflecting a more flexible, everyday approach to the dish.

Perhaps for these reasons, it is widely said in Vietnam that phở originates from Nam Định. It is possible that phở emerged from this culinary context—evolving as a more “pot-au-feu–like” interpretation of xáo trâu.While still eaten with rice noodles and beef, phở introduced a lighter,clearer, and more refined broth, elevating the dish into somethingmore delicate and nuanced.

In this sense, whether phở emerged through a sudden moment of invention or a gradual process of refinement remains unknown. All attempts to trace its origins are, at best, informed efforts rather than definitive conclusions, as no single, authoritative source can precisely identify the dish’s beginning.

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A Small History Fact

A relevant historical context further clarifiesthis practice. During the Lý and Trần Dynasties, the slaughter of buffalo and cattle was strictly prohibited. These animals were essential to wet-rice agriculture, valued primarily for plowing and farm labor rather than for consumption. As a result, xáo trâu was typically prepared only when animalshad grown old or were nearing the end of their working lives.

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3. Toppings

The use of beef is almost certainly influenced by French culinary practices, as Vietnamese cuisine traditionally did not center around beef consumption.

Earlier and more locally rooted variations—such as those using water buffalo or chicken—align more closely with longstanding Vietnamese culinary traditions.

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The earliest documented reference to phở is

Existing historical records suggest that the term “phở” appeared relatively late in written documentation.
The earliest known reference to date is found in “Technique du peuple Annamite” (1908–1909) by Henri Oger.

Henri Oger (full name Henri-Joseph Oger) was a French volunteer who served in northern Vietnam (Tonkin). He is best known for his extensive collection of woodblock-style drawings and sketches depicting the everyday life of the Vietnamese people in the early 20th century. Within this work, illustrations of itinerant phở vendors in Hanoi appear clearly, indicating that phở was already part of urban life at the time.

Subsequent sources further confirm the establishment of phở as a distinct dish. Notably, the 1920 dictionary published by the École française d’Extrême-Orient (EFEO) provided clear definitions of phở and its variations, including phở chín and phở tái, demonstrating that the dish had by then become formally recognized and categorized.

 Pic 2 : Peanut worm after the drying process.

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