A cafe in Hue is pouring something that sounds like a dare: coffee laced with fermented krill paste, the salty condiment that anchors central Vietnam's most famous dishes. TOC Gallery, on Nguyen Thi Minh Khai Street in Thuan Hoa Ward, rolled out the drink in early September and has watched foot traffic climb about 20 percent since. The kitchen now makes roughly 50 cups a day at 55,000 VND, or around $2.20 each.

Co-owner Tran Ngoc Anh Tuan, 32, wanted to pull Hue's imperial-era food heritage into modern cafe culture. The city already has a beloved signature in salt coffee, sipped near the old citadel walls, so his team went hunting for something bolder. They landed on mam ruoc — tiny sea krill mixed with salt and slow-fermented in earthenware jars under the central Vietnamese sun, the savory backbone behind bun bo Hue and com hen.

The logic, it turns out, is chemistry. Krill paste's natural salinity softens the bitter edge of roasted coffee, whereas sour ingredients would curdle cream. Plenty of locals thought the idea was absurd, and the team needed six months of testing to get it right. The paste is simmered with caramel syrup and fresh whipping cream, which tames the fishy punch into something buttery.

The finished drink is built in four layers. A base of chilled fresh milk and condensed milk sits under an espresso pulled from Arabica beans grown in Hue's A Luoi highlands blended with Vietnamese Robusta. On top goes the krill-infused cold cream, finished with shavings of dried bonito flakes. Tuan's advice: skip the straw, stir only the milk and espresso below, and sip straight from the glass so the savory cream hits your palate first.

First-time drinkers are converting. Quoc Bao, a 28-year-old visitor from Ho Chi Minh City, expected a fish bomb and found the aroma far gentler than advertised, with a clean savory finish. Bich Ngoc, 35, travelled from Nghe An after seeing viral clips, and came away calling the balance fascinating and delicious.

For travellers, this is Hue doing what it does best — treating food as history you can taste. It's a cheap, memorable stop for anyone already visiting the citadel or the tombs, and a genuine conversation starter that still respects the ingredients locals grew up with. If your travel style rewards the unusual over the safe, this cup belongs on your Hue list.