Bún đậu mắm tôm: an honest guide to the shrimp paste

Bún đậu mắm tôm is the dish that separates people who like Hanoi food from people who like the idea of Hanoi food.

It arrives as a tray — a woven bamboo tray lined with banana leaf, loaded with cold noodle cakes, blocks of tofu straight out of the fryer, a fistful of herbs, boiled pork belly, and a small bowl of greyish-purple paste that smells, on first encounter, like a harbour at low tide.

That paste is mắm tôm, and about half of visitors decide against it within one second of it reaching the table.

This article is a fair hearing for the dish. It includes an exit route.

What is on the tray

Bún lá — rice vermicelli pressed into flat cakes and cut into squares. Room temperature. Plain on purpose; they are the neutral ground.

Đậu rán — tofu, deep-fried to order so the outside is blistered and the inside is still custardy. This is the best thing on the tray and it must be hot. Cold fried tofu is a waste of everyone’s time.

Thịt luộc — boiled pork belly, sliced thin, usually with a good ratio of fat. Some trays use thịt chân giò (rolled pork knuckle) instead.

Chả cốm — in autumn, a pork patty bound with young green rice. Chewy and faintly sweet. If it is offered, take it.

Herbs — tía tô (perilla), kinh giới (Vietnamese balm), cucumber, sometimes raw green banana or starfruit. The perilla in particular is doing real work against the paste.

Extras, depending on the shop: nem chua rán, dồi (blood sausage), lòng (offal), fried intestine. A full tray — a mẹt đầy đủ — has all of it.

And the mắm tôm.

What mắm tôm actually is

Small shrimp, salted and fermented for months, then ground. That is the whole thing. It is a preservation technique older than the city.

Raw from the jar it is genuinely aggressive. That is not how it is served, and this is the part that matters:

Mắm tôm is not finished until you finish it.

At the table you will find lime, sugar, chilli, and usually a small bottle of hot oil or rượu trắng. What you do:

1. Squeeze in lime — a lot, half a wedge or more.
2. Add a small spoon of sugar.
3. Whip it with your chopsticks. Hard, for ten or fifteen seconds. It will lighten from grey-purple to a pale foamy lavender and roughly triple in volume.
4. Add chilli, and a few drops of the hot oil from the tofu pan if there is any going.

Whipped, it is salty, sour, deeply savoury, and nothing like what came out of the jar. The funk is still there but it sits underneath rather than on top. This is the difference between the dish working and not working, and almost no one tells visitors to do it.

The exit route

If you try it and it is not for you, you have not ruined your lunch.

Ask for nước mắm — plain fish sauce with lime, sugar and chilli, which every bún đậu shop has. The tray is still excellent: hot fried tofu, cold noodles, pork, herbs. You are eating a good meal, just not the canonical one.

You can also head this off at ordering by saying “mắm tôm để riêng” — shrimp paste on the side — and asking for a fish sauce bowl too. Nobody minds.

How to eat it

There is no bowl. You build each bite on your chopsticks.

A piece of noodle cake, a piece of tofu, a leaf of perilla, a slice of pork. Dip the assembled bite — lightly — in the sauce. Eat.

The two common mistakes:

• Dipping too deep. The sauce is intense. A touch is enough.
• Letting the tofu go cold. Eat the tofu first and fastest. Order a second round of tofu halfway through if it is going well; most shops will fry more.

Where to look

The student districts in the west do the cheapest and frequently the best trays in the city. Volume means the fryer never stops, which means the tofu is always hot. Prices there start around 50,000.

Alley shops throughout the Old Quarter and the southern districts. Look down alleys at lunchtime for a row of low tables and stacked bamboo trays. The good ones have no sign worth reading.

What to avoid: air-conditioned bún đậu restaurants with photographs on the wall and a set-menu board in English. They are not bad, exactly, but they fry in batches and the tofu sits.

The test, as with most of this city: is there a fryer, is it running, and is the tray going out the moment the tofu comes out of it.

When

Lunch. Roughly 10:30am to 2pm is the real service. Some shops run into the evening, particularly in the student areas, where bún đậu doubles as drinking food.

What it costs

50,000–70,000 VND for a basic tray — noodles, tofu, pork, herbs. 90,000–120,000 VND for a mẹt đầy đủ with everything on it. Shared trays for two or three people are common and cheaper per head.

A word on the smell

It travels. The dish is normally eaten in open-fronted shops and alleys for a reason.

If you are sensitive to strong smells, sit at an outside table and order the paste on the side. If you are eating it before a long taxi ride or a flight, be aware that the smell stays on your hands — most shops have a tap or a wet wipe for exactly this reason.

If you only do one thing

Go at noon, in the student districts, to an alley with low tables and a fryer going. Order a tray and ask for the paste on the side plus a bowl of fish sauce.

Whip the mắm tôm with lime and sugar until it foams pale. Take one bite with a leaf of perilla and a piece of tofu still too hot to hold.

If you like it, you have unlocked a large part of how this city eats. If you don’t, the fish sauce is right there and the tofu is still the best thing you will eat that day.

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Next: bún riêu cua — the tomato-and-crab bowl to order when you are bored of phở.