What is cao lau?
Although it is not uncommon to find noodles of many kinds in Vietnamese cuisine, cao lau stands out as one-of-a-kind, from its fascinating history to the meticulous process of making the unique noodles exclusively used for the dish. Cao lau is a long-established specialty, valued not only for its culinary significance but also as a symbol of Hoi An Ancient Town. Read on to discover what makes cao lau noodles so exclusive and what gives the dish its unmistakable appeal.
The origin of cao lau
Let’s go back in time. Between the 2nd and 17th centuries, under the reign of Champa – an ancient Indochinese kingdom spanning the central and southern coastal regions of Vietnam – Hoi An (formerly Lam Ap) was a fertile land where economic and cultural exchanges flourished.
With prosperous trading activities along the Silk Road and Ceramic Road at the time, Hoi An became a significant stop on the international trade route, thanks to its favorable maritime conditions and developed system of waterways. The strategic port of Hoi An attracted many merchant ships from both the West and the East, including Arabs, Persians, Chinese, and Japanese. Among these, China and Japan left the most profound and long-lasting cultural influences on Hoi An, with many architectural landmarks, such as the Japanese-style footbridge and the Teochew Assembly Hall, still standing in the ancient town today. From this rich cultural exchange emerged many versions of the origin story of the dish. Yet, no solid evidence proves which one is most legitimate. We will walk you through all the hypotheses about the origin of cao lau and let you decide for yourself.
Champa origin
Some believe that cao lau dates back to the Champa kingdom because the noodles are traditionally made using fresh water from Ba Le Well – a symbolic and fully functional heritage site built during Champa times. Elderly residents and artisans in Hoi An claim that cao lau noodles lack their authentic taste without the groundwater from this well. However, this connection only supports the origin of the noodles themselves, not cao lau as a complete dish.
Chinese influence
Another hypothesis suggests that cao lau was brought to Hoi An by Chinese immigrants or, at the very least, is strongly influenced by Chinese cuisine. This is evident in the use of char siu pork, a common ingredient in many Chinese noodle dishes. Additionally, the use of soy sauce for marinating and seasoning, rather than fish sauce, further indicates Chinese influence.
Japanese influence
This argument likely stems from the shape of the noodles. Unlike other types of Vietnamese rice noodles, cao lau noodles are thought to resemble udon noodles, which are thick and distinctly square-ish. However, cultural anthropologist Nir Avieli pointed out in his book Rice Talks: Food and Community in a Vietnamese Town, a culinary ethnography of Hoi An, that cinnamon – one of the five spices used in cao lau – is never included in Japanese savory dishes. He even quoted Japanese students who noted that cinnamon is primarily used in beverages and confections in their cuisine.
How did the name cao lau come about?
The name cao lau itself sparks discussion among food enthusiasts and scholars. A common explanation ties the name to its vendors. In Hoi An, most shops and restaurants were built along the river and elevated high above the water level. (You can still see these structures when visiting Hoi An Ancient Town today.) Diners would often climb to the upper floors to enjoy their meal while watching the boats come and go beneath them. Over time, these elevated noodle shops became closely associated with the dish, leading to the name ‘cao lau’, which means ‘high floor’.
Another explanation for the name cao lau relates to the process of making the noodles. According to the Sino-Vietnamese system, cao lau can be interpreted as ‘mi go’, or ‘wooden noodles’. This refers to the step in which the noodle strands are soaked in a mixture of water and ash derived from burned wood sticks. Additionally, in the same system, ‘cao’ can mean ‘delicacy’, aptly reflecting the dish’s esteemed status on the Vietnamese culinary map.
Ultimately, each hypothesis has its merits but is not without flaws. While no one knows exactly when this dish originated, its mysterious history only adds to the allure of cao lau – a dish already captivating in its essence.
Cao lau ingredients
Unlike other noodle dishes like pho or bun bo Hue, cao lau is served in a bowl with only a small amount of broth, almost invisible on the surface. Traditionally, a bowl of cao lau consists of noodles, char siu pork, deep-fried rice crackers, fresh green vegetables, and broth.
Noodles
The three essential ingredients for cao lau noodles are rice, fresh water, and lye water. The process of transforming these simple ingredients into the delicate and unique noodles is remarkably meticulous.
- Rice: The rice must be harvested at just the right time. If the grains are too fresh, the noodles lose their chewiness. Conversely, overly aged rice grains affect the glutinous quality, making the noodles difficult to shape.
- Fresh water: Only water from the Ba Le Well – a Cham-era heritage well dating back to the 7th or 8th century – is traditionally used. The well’s pure groundwater is considered the secret ingredient that enhances the authentic taste of cao lau.
- Lye water: Known as nuoc tro in Vietnamese, lye water is a food additive made by mixing ash from burned wood, rice straw, or citrus peels with water. This solution, rich in potassium and sodium carbonate salts, is crucial to the noodle-making process. The potassium strengthens the starch and gives the noodles their distinctive yellow-brownish hue.
Although industrial machines are increasingly used to mass-produce cao lau noodles, most vendors in Hoi An remain loyal to traditional methods. They understand that nothing can replicate the unique woody and starchy flavor of handcrafted noodles made through hours of meticulous effort.
Char siu pork
The char siu pork in cao lau differs from its Chinese counterpart due to the spices used for marination. Lean cuts, such as pork thigh, are preferred. The pork is first marinated with garlic and shallot juice, followed by soy sauce, brown sugar, five-spice powder, pepper, and chili. It is left to rest for 2-3 hours.
The marinated pork is fried until golden brown on both sides, then simmered in water and the marinade until tender. This step also thickens the sauce. The pork is turned every 10-15 minutes during simmering to ensure an even reddish-brown color. After about 45 minutes, the pork is cooled and sliced thinly. The thickened sauce is saved for later use in the broth.
Broth
The reduced sauce from the pork marinade is diluted with water and simmered to create the broth. A small scoop of this broth is added to the bowl during serving – just enough to coat the noodles lightly.
Rice crackers
Rice crackers, or ram, are made from cao lau dough cut into squares instead of noodles. These crackers resemble the prawn crackers often found in Vietnamese salads. Deep-fried until crispy, they add a light and crunchy texture to the dish.
Green vegetables
Cao lau is served with a variety of fresh herbs and vegetables. Common additions include baby mustard greens, Vietnamese coriander, mint, bean sprouts, and banana blossoms. In Hoi An, these greens are often sourced from Tra Que Vegetable Village, a historic farming community and must-visit destination. Lime wedges and chili paste are optional, offering extra layers of flavor.
What are the differences between cao lau and mi Quang?
Due to the unique preparation process of cao lau, which requires a meticulous series of steps to achieve its distinctive flavor, there are few regional variations of the dish. However, its presentation – minimal broth and rice crackers on the side – often leads to it being mistaken for mi Quang, another beloved specialty from Central Vietnam. Below are some key differences to help you appreciate and differentiate between these two iconic dishes.
Colors of the noodles
- Mi Quang noodles are typically bright yellow, achieved by adding turmeric powder. In some cases, you may also find ivory or white noodles, but they are always broad and flat in shape.
- Cao lau noodles, on the other hand, derive their unique color – ranging from yellowish to brownish – from the use of lye water during the preparation process, giving them a distinct woody undertone.
Intensity of the broth
- The broth in mi Quang is light and delicate, made by simmering pork bones to extract subtle flavors.
- Cao lau broth is more concentrated, with a richer flavor derived from the reduced marinade used to prepare the char siu pork.
Variety of toppings
- Mi quang offers a greater variety of toppings, including pork, shrimp, chicken, frog, and sometimes snakehead fish. It is also served with banh da, crispy rice crackers made from tapioca and black sesame seeds, which add an aromatic crunch.
- Cao lau sticks to tradition, featuring char siu pork as its primary topping and paired with ram, deep-fried rice crackers made from cao lau dough.
When to eat cao lau
Compared to other noodle dishes, cao lau is believed to be lighter because the starch cells are broken down after being soaked in lye water, making it easier to digest. Additionally, you cannot rush the process of appreciating the exceptional taste of cao lau. Its subtle woody and herbal flavors require diners to take their time, savoring each bite slowly. This is why it is not the best option for breakfast, which is usually quick and portable.
Where to eat cao lau
Cao lau is best enjoyed at a local vendor along the Hoai River, which runs through the ancient town. Imagine savoring this time-honored delicacy in the heart of a UNESCO World Heritage town, beside a river aglow with light. The tranquil water reflects the magical hues of candlelight, lanterns, and the moon. We believe that the enchanting surroundings will enhance your dining experience.
