Water bug chronicles: the secret ingredients in Hanoi's rice rolls

Banh cuon, a traditional delight with its origins in Hanoi's Thanh Tri Village, has been characterized as the true gift of Hanoi in the book of "Hanoi's 36 Streets," a work penned by writer Thach Lam about Hanoi's foods and their connection with the city's cultural-social life.

While rice rolls are enjoyed across various regions, it is the unique Thanh Tri variant that includes a rare water bug - ca cuong (Lethocerus indicus), which is found in ponds, lakes, swamps, and fields.

Thanh Tri Village's rice rolls are accompanied by a bowl of fish sauce featuring pork rolls and the essence of 'ca cuong', enhanced with herbs. Photo by VnExpress

Hoang Thi Lan, 68, has upheld the family's banh cuon tradition since 1960. Her mother and grandmother used to be street vendors selling the dish along Hanoi streets. About 20 years ago, she also sold this dish as a street vendor near Kham Thien Market.

In 2008, she opened an eatery on Thanh Tri Ward, Hoang Mai District. Now, she has passed the business to her son, Cuong, who is the fourth generation carrying on the tradition and expanding the business with more locations in Hanoi's Old Quarter.

The restaurant serves customers from 5 a.m. to noon and from 4 p.m. to 6 p.m. It occupies an area of about 30 square meters, featuring two stainless steel tables, two benches, and plastic chairs, accommodating up to 20 customers at once.

The walls of the restaurant are adorned with awards from craft village competitions since 2006, showcasing the family's time-tested recipe and Lan's expertise, which she has honed since she was just 15 years old.

Daily preparations involve 10 kilograms of rice, 10 liters of sauce, three kilograms of shallots, one kilogram of scallions, 5 kilograms of ground pork, and 6 kilograms of pork rolls, among other ingredients.

Shallots are sliced thinly and fried until they turn golden brown. The filling, a mixture of wood ear mushrooms and minced shiitake mushrooms, is stir-fried with pork. Scallions are stir-fried with fat to be added to each layer of the cake.

The heart of banh cuon is its rice flour, chosen and prepared by Lan. To ensure the rice rolls are neither too brittle nor sticky, she selects Khang Dan rice from the previous harvest. She explains, "Khang Dan is a type of dry rice with small, sturdy grains that resist breaking or sticking during steaming."

The rice is soaked for about three hours, ground into a paste, and left to settle for approximately two hours. Afterward, the water is drained to remove impurities, and fresh water is added following her secret formula to achieve the desired texture and consistency.

The cooking area is located to the left of the entrance, where customers can enjoy piping-hot rolls freshly handcrafted.

Hoang Thi Lan makes rice rolls at the entrance of her eatery in Thanh Tri Village, Hanoi. Photo by VnExpress

Lan pours spoonfuls of batter onto a flat cloth atop the steamer, ensuring even distribution and creating the desired puffiness in the rolls. Once cooked, the rolls are retrieved using a flat bamboo stick, flattened, and then customized with either scallion fat or fillings according to each customer's preference.

She remarks, "The most challenging thing is getting the timing right to ensure the rolls are uniformly cooked and not mushy."

According to Lan, the authentic Thanh Tri rice rolls are adorned with scallion fat only. In addition to the traditional option, patrons can enjoy rice rolls filled with meat and wood ear mushrooms, an innovation that has gained popularity among the locals over time.

A serving of banh cuon with scallion fat contains 13 to 15 layers of rice rolls, while the meat-filled rolls come in sets of 10. Both options are priced at VND20,000 (US$0.80). If desired, diners can also order additional pork rolls or eggs.

Each layer of the rice rolls boasts a clean white appearance, coupled with a flexible texture, coated in flavorful scallion fat. An accompanying bowl of sweet and sour dipping sauce, enhanced by pork rolls, enriches the experience. For an extra burst of flavor, customers can ask for ca cuong.

Ca cuong, when grilled, emits a potent, spicy, and flavorful scent, making it suitable for direct consumption or as a condiment for dipping sauce. Lan noted that, "In recent times, ca cuong has become increasingly rare. Some establishments resort to using the bug's essential oil in their dipping sauces, but it doesn't compare to the richness of whole bug."

A serving of ca cuong at the shop costs VND70,000 ($2.90), over three times the price of a plate of rice rolls, making it a special treat for those who appreciate its unique flavor.

Despite its location 10 kilometers from Hanoi's city center, the restaurant consistently attracts a steady stream of diners. Each day, it serves around100 portions (over 1,000 individual rolls) for on-site dining alone, not including takeout orders.

Lan personally oversees the preparation of the rice rolls and manages the key steps to craft each plate, while her husband attends to the dipping sauce, slices the rolls, and garnishes them with fried shallots.

Hoa, a 57-year-old resident of Thanh Tri, has been a loyal customer of Lan's shop for more than 20 years. She often buys rice rolls, usually with a serving or two of ca cuong, to enjoy at home. "Every now and then, I try different places to try new flavors, but Lan's restaurant is still my top choice. Other places use ca cuong essential oil, and it can't compare to the genuine ca cuong here."

In Dai Mo Ward, an 84-year-old resident named Nguyen Trong Hoi shared his perspective, stating that enjoying these rolls is like embarking on a journey. "From the initial bite, one can sense the richness, and with each swallow, the sweetness and tenderness linger. The scallion fat adds to the delight, harmonizing beautifully with the rolls' flavors, resulting in a balanced and enjoyable taste," Hoi said.