1137. Southeast Asia Liaison Office News #6: Vietnamese Fermented Rice Noodles "Bún"

Rice noodles made by fermenting rice are eaten not only in Thailand but also in other Southeast Asian countries such as Vietnam, Laos, Cambodia, and Myanmar.

JIRCAS has been conducting research on "Khanom Chin" or "Khanom Jeen," a traditional Thai fermented rice noodle, with Kasetsart University in Thailand.
https://www.jircas.go.jp/en/publication/research_results/2020_c02
https://www.jircas.go.jp/en/publication/research_results/2019_c01

I visited manufacturing plants for fermented rice noodles called "Bún," so today I will introduce Bún.

What is the difference between the Vietnamese noodles "Pho" and "Bún"?

Pho and Bún are different in appearance. Bún is long and thin, with a round cross-section, while Pho is large, flat, and rectangular in cross-section. This is due to the molding process. Bún is made by pushing it out of a "mold" with many small holes, so it has a round cross-section like spaghetti. On the other hand, Pho is made by cutting flat, stretched batter, so it has a flat cross-section like Japanese KISHIMEN noodles.
Secondly, the way the noodles are cooked during the manufacturing process is different. Bún is boiled in boiling water as soon as it is pushed out into threads through small holes, while Pho is made by steaming thin, flat batter.
And the most different feature is the presence or absence of a fermentation process. Bún is fermented rice noodles, and the manufacturing process involves lactic acid fermentation. This process gives the noodles a smooth and bouncy texture.

Manufacturing process

Many of the factories we visited make it in the following way, so we will introduce it here.

 ① Washed rice is soaked in water for a day (lactic acid fermentation begins at this stage).
 (Some factories leave the washed rice for a few days before soaking it in water to promote lactic acid fermentation.)
 ② Grind the rice into flour while it is still in water, and leave it with the water overnight to allow fermentation to proceed.
 ③ Remove the water and refine only the rice flour.
 ④ Mix the rice flour and water to make a thick liquid.
 ⑤ Press the noodles into threads through a mold with small holes and boil them in boiling water. 
 ⑦ Rinse with water, drain, and it's done.

Vietnamese Bún Dishes

First, there is a type of noodle dish called Bún Chả. Bún and raw vegetables are placed on a plate, and you eat them by dipping them in a bowl of sweet and sour dipping sauce containing grilled pork. Fried spring rolls made from rice paper are also a popular side dish and are eaten by dipping them in the sauce.
There is also a Vietnamese-style mixed noodle dish. This one is called Bún Trộn. This already has vegetables on it, and you can add seasonings to your liking and mix it in.
There is also a beef noodle dish called Bun Bò Huế, a specialty of the ancient capital of Hue in central Vietnam. The noodles used here are a size thicker than the noodles I saw at the factory.

Pho is overwhelmingly more famous, but Bún is just as popular in Vietnam. It is especially customary to eat Bún for breakfast. If you visit Vietnam, try enjoying the texture of fermented rice noodles called Bún.

Contributor: KANAMORI Norihito, Southeast Asia Liaison Office