How to Make Authentic Northern-Style Sour Soup with Duck and Sau with Taro
This Northern-style Sour Soup with Duck and Sau (Vịt om sấu) with taro is a delicious and authentic recipe. The biggest challenge in making this dish is ensuring the broth remains clear, not dark, and has a mild, refreshing sour taste. In this article, Cookbeo shares some important tips to make this dish truly appealing.

Ingredients
- Duck: 1 duck, approximately 1.5kg
- Sau fruit: 10 pieces
- Taro: 4-5 small roots
- Lemongrass: 5-6 stalks
- Shallots, garlic, chili
- Cilantro, scallions, rice paddy herbs
- Coarse salt
- Lime
- Ginger wine
- Coconut: 1 coconut
- Herbs, rice vermicelli (to serve)
- Seasoning: fish sauce, sugar, MSG, seasoning powder, pepper

Instructions
Prepare the Ingredients
Ask the vendor to handle the initial cleaning, feather plucking, and cutting of the duck. Once home, rinse the duck thoroughly. Rub the duck with coarse salt, ginger wine, and fresh lime to remove any odor and ensure it is clean. Alternatively, you can crush some custard apple leaves and rub them over the duck, then rinse it off before cutting the duck into bite-sized pieces.
To ensure cleanliness and taste, it's recommended to remove the duck's beak, feet, and tail, as these parts are often the most unsanitary.
After cleaning and cutting the duck, marinate it with 2 tablespoons of fish sauce, 1/2 teaspoon of MSG, 1/2 teaspoon of seasoning powder, 1/2 teaspoon of pepper, and 1/2 teaspoon of sugar.

Mince the shallots and garlic. Crush the lemongrass, cut it in half, finely chop the roots, and shred the tops. Add a bit of the minced shallots, garlic, and lemongrass to the marinated duck for extra fragrance. Let the duck marinate for about 15 minutes.


Wash the cilantro, scallions, and rice paddy herbs, then chop them finely. Slice the fresh chili.
Clean the taro to remove any dirt. Bring a pot of water to a boil, add the taro, and blanch it for about 3 minutes. Drain, rinse under water, and peel the taro to remove any stickiness and prevent itchiness when eating.


Cook the Sour Soup with Duck and Sau

Stir the duck until the meat firms up, then add the coconut water and about 1.5 liters of water. This amount is enough for 4-5 servings, so adjust the quantity accordingly. Add the sau fruits, and cover the pot.
When the broth comes to a boil, remove the sau fruits, mash them, discard the seeds, and return the sau pulp to the pot. Stir well, then season with 2 tablespoons of fish sauce and 1 teaspoon of seasoning powder. Cover the pot again, lower the heat, and simmer for about 20-25 minutes.
Since duck meat is fatty, skim off any foam and excess fat during cooking to keep the broth clear and light.

Add the taro at the end to prevent it from becoming mushy, which helps maintain a smooth texture. Adjust the seasoning to taste, then add the cilantro, scallions, and rice paddy herbs, along with a few slices of chili, before transferring the sour soup to a serving bowl.
Sour Soup with Duck and Sau is best enjoyed with rice vermicelli and fresh herbs, and should be served hot to fully appreciate its flavors. The clear broth, tender duck meat, and the combination of sour sau and creamy taro create an irresistible dish, especially during the hot summer months.

Cookbeo has shared these important tips on how to make Sour Soup with Duck and Sau, ensuring a clear broth, tender duck, intact taro, and a perfectly balanced sour taste. Hopefully, these tips will help you confidently prepare this delicious dish at home without needing to visit a restaurant.

Final Product Requirements
Sour Soup with Duck and Sau is a famous dish, deeply connected to Hanoi's culinary culture. This dish captivates diners with the sweetness of the duck meat, the refreshing sourness of sau, and the creamy richness of taro. The clear broth has a gentle, refreshing sourness, making it an ideal dish for hot summer days.
The broth is clear and perfectly balanced in sourness. Many people struggle with issues like tough duck meat, broth that is too sour or not sour enough, or a dark, cloudy broth that lacks the desired freshness.
Tips & Notes
When selecting the duck, avoid choosing one that is too lean or too fatty. A lean duck will have little meat, while a fatty duck can make the dish greasy.
Sau fruit is currently in season and readily available in markets. For a duck weighing around 1.5kg, use about 10 sau fruits. If you prefer a more sour flavor, you can add 1-2 more, or reduce the number if you prefer a milder taste.
When choosing taro, select firm, undamaged roots.

For Sour Soup with Duck and Sau, cilantro is essential, along with rice paddy herbs and scallions. However, be cautious with the amount of rice paddy herbs used, as too much can make the broth bitter.