During the hot summer months, xu xoa becomes one of the most sought-after refreshments for visitors to Ly Son Island. The cool, silky bowls of seaweed jelly can be found at roadside stalls and local markets across the island. Yet few people realize how much effort goes into creating this humble but iconic specialty.
A Unique Ingredient: “Rau Đông” – The Signature Seaweed of Ly Son
Ly Son’s xu xoa is made entirely from rau đông, a natural seaweed species that grows on rocky reefs surrounding the volcanic island. The seaweed appears most abundantly during the rainy season and is harvested from the first to the fourth lunar month.
After being collected from the sea, the seaweed is sun-dried along stone embankments around the island. Once the first layer of sunlight removes some moisture, locals spread the seaweed across shallow tidal flats to shake off the sand and tiny stones attached to its roots.
The Most Challenging Step: Cleaning and Preparing the Seaweed
According to families who specialize in purchasing and processing rau đông, the most demanding part of the process is washing it thoroughly to eliminate the fishy smell and mineral residue. To ensure clean, high-quality seaweed, it must be:
- Washed once with seawater
- Washed 3–4 more times with fresh water
- Sun-dried after every wash
This repetitive, labor-intensive process means that only a few households on Ly Son still maintain the traditional craft. Once fully cleaned and dried, premium rau đông sells for around 350,000 VND per kilogram.
Turning “Rau Đông” Into Xu Xoa – The Island’s Famous Cooling Dessert
Dried seaweed is soaked overnight, rinsed again, and then simmered in fresh water. As it dissolves completely, the liquid is poured into bowls or molds and left to cool and set into a delicate jelly known as xu xoa.
What sets Ly Son’s xu xoa apart from the versions made with commercial agar powder on the mainland is its:
- 100% natural seaweed base
- Soft, melt-in-your-mouth texture
- Light, refreshing ocean-breeze flavor
To help the seaweed break down faster and set more firmly, cooks often add a small amount of lime juice or alum.
Xu xoa is typically served with:
- A syrup made from caramelized golden sugar
- Lightly roasted ginger for a warm, fragrant finish
Xu Xoa – The Signature Summer Specialty of Ly Son Island
From February to September, xu xoa becomes the island’s bestseller. Many shops prepare extra batches not only for tourists to enjoy on the spot but also for takeaway orders shipped to the mainland. Alongside seafood and traditional specialties, xu xoa has become a popular souvenir among travelers.
More than just a refreshing dessert, Ly Son’s xu xoa reflects the livelihood, culture, and natural bounty of this volcanic island—making it a truly meaningful gift from the sea.
