(photo: Hien Ngoc)
The most apparent difference is that sour pho is mixed with a cool, tangy-sweet sauce and consumed by mixing all the ingredients together like a salad or "nom," which is common in the lowlands.
Lien, the owner of a sour pho restaurant in Lang Son city, explained that a bowl of sour pho comprises two parts.
The dry part includes banh pho (rice noodles) that are briefly dipped in warm water. The noodles used must be thick and resilient to avoid breaking during the cooking process.
The dish also contains char siu pork, tripe, crispy-fried liver, thinly sliced sausage, fried potato or sweet potato sticks, dried onions, cucumbers, fresh herbs, and roasted duck - a renowned specialty of Lang Son.
The liquid part consists of sauce used to mix with pho. Sour pho in Lang Son isn’t served with hot broth but combined with a thick, brown sauce that features a blend of sour, spicy, salty, and sweet flavors.
"This sauce is made from the fat drippings from roasted duck or duck boiled water, then seasoned with a variety of spices such as sautéed onions, garlic, fish sauce, chili, vinegar, sugar, ginger, and finally thickened with some tapioca starch," Lien said.
At some restaurants, additional broth may be served alongside the pho, which is the extract from the duck's abdomen during roasting or from pure boiled duck broth, ensuring a rich, fatty flavor with a distinctly aromatic smell.
Lang Son sour pho is usually served on a large, deep plate, accompanied by a dozen different ingredients.
When eating, diners mix the sauce with the ingredients such as a few slices of chili, spicy bamboo shoots, or lemon juice to enhance the aroma and intensify the flavors.
Dang Sang, a diner from Hanoi, said the sour pho attracts customers with its refreshing taste, offering a perfect balance of salty, sweet, sour, and spicy flavors, suitable for cooling down after Tet holiday, when people eat many fatty dishes. The pho is also a good choice for summer.
“Sour pho has an unusual flavor that is easy to eat, suitable to both children and the elderly. I've tried this dish in several other provinces but nowhere is it as delicious and authentic as in Lang Son,” he said.
Thao Trinh