Vietnamese Egg Drop Crab Soup Recipe

Vietnamese egg drop crab soup, often called súp cua, is a gently thickened soup with sweet crab, tender egg ribbons, and a savory broth. Corn, mushrooms, and asparagus are common additions, though recipes vary from one cook to another. This version is straightforward to make at home and works well as a light meal or a warm first course.

Ingredients

6 cups (1.42 L) low-sodium chicken broth
8 oz (227 g) fully cooked crab meat, picked over for shell fragments
2 large eggs (about 100 g without shells), beaten until the whites and yolks are combined
4 oz (113 g) fresh shiitake mushrooms, stems removed and caps thinly sliced
1 cup (150 g) corn kernels, fresh or thawed if frozen
1 cup (130 g) asparagus, cut into ½-inch (1 cm) pieces
3 tbsp (24 g) cornstarch
¼ cup (60 ml) cold water, for the cornstarch slurry
1 tbsp (15 ml) fish sauce
¼ tsp (1.5 g) fine salt, plus more only if needed
⅛ tsp (0.3 g) ground white pepper
1 tsp (5 ml) toasted sesame oil
2 scallions (about 30 g), thinly sliced
¼ cup (10 g) loosely packed cilantro leaves, roughly chopped

Instructions

Prepare the ingredients. Check the crab carefully for bits of shell and separate any large pieces into bite-size chunks, keeping some lumps intact. Slice the mushrooms, cut the asparagus, beat the eggs, and measure the broth and seasonings. This prep takes about 20 minutes if you work at a relaxed pace; keep the crab chilled while you prepare the vegetables.
Simmer the vegetables. Pour the chicken broth into a medium or large saucepan and bring it to a boil over medium-high heat. Add the mushrooms, corn, asparagus, fish sauce, salt, and white pepper. Lower the heat to maintain a gentle simmer and cook for 6 to 8 minutes, until the asparagus is tender but still holds its shape and the mushrooms have softened. Avoid a hard boil, which can make the broth reduce faster than expected.
Thicken the broth. Stir the cornstarch and cold water together in a small bowl until no dry lumps remain. Stir the simmering broth in a slow circle, then pour in the slurry gradually. Cook for 1 to 2 minutes, stirring often, until the broth turns lightly glossy and coats a spoon. Stir the slurry again just before pouring if it has been sitting; cornstarch settles quickly.
Warm the crab. Add the cooked crab and fold it through gently so the larger pieces stay intact. Simmer for about 2 minutes, just until the crab is hot. If the crab is already finely shredded, take care not to stir vigorously, or it can disappear into the thickened broth.
Make the egg ribbons. Reduce the heat so the soup is just below a vigorous boil. Slowly drizzle in the beaten eggs in a thin stream while moving a spoon gently through the soup. Let the egg sit for about 10 seconds, then stir once or twice to form soft ribbons rather than tiny scrambled bits. Continue cooking until the soup reaches 160°F (71°C), checking with a food thermometer in the center of the soup without touching the pan; USDA FSIS lists 160°F (71°C) as the safe minimum temperature for egg dishes.
Finish and serve. Turn off the heat and stir in the sesame oil and most of the scallions. Taste the broth before adding more salt, since broth and fish sauce vary in saltiness. Ladle into warm bowls and scatter the cilantro and remaining scallions over the top. The soup is ready as soon as it is garnished, so serve it while the egg ribbons are tender.

Tips

Use cooked crab and check it carefully. Refrigerated pasteurized crab, fresh cooked crab, or well-drained canned crab all work. Pick through it for shell, and keep it chilled until it goes into the pot. Canned crab can be saltier and more finely flaked, so taste the broth before adding extra salt.
Keep the egg stream fine. Pouring the egg slowly into gently moving soup creates recognizable ribbons. If the soup is boiling hard or you pour the eggs all at once, they are more likely to form clumps. A fork or small whisk makes it easier to beat the eggs evenly before adding them.
Adjust thickness gradually. This recipe makes a lightly thickened soup, not a spoon-standing pudding. If you prefer it thicker, mix another 1 teaspoon (3 g) cornstarch with 1 tablespoon (15 ml) cold water and stir it in a little at a time. If it becomes too thick, loosen it with warm broth or water.
Use a substitute thoughtfully. If shiitakes are unavailable, use 4 oz (113 g) of cremini mushrooms; the flavor will be milder and less earthy. Fish sauce gives the broth a rounded savory note, but you can replace it with 1 tablespoon (15 ml) light soy sauce for a different, slightly less seafood-forward flavor. Reduce added salt when using either substitution.

Serving Suggestions

Serve the soup in small bowls as a first course, or make it a simple meal with steamed jasmine rice, rice noodles, or a crusty roll for dipping. A bowl of plain rice is especially useful if you make the broth a little saltier or thicker than you intended, because it balances the soup without competing with the crab. For a larger meal, pair it with fresh spring rolls, a crisp cucumber salad, or a plate of lightly steamed greens.

Offer lime wedges, sliced scallions, and white pepper at the table so each person can adjust the seasoning. A small drizzle of sesame oil can add aroma, but use it sparingly because it can cover the delicate taste of the crab. Serve the soup hot, but not bubbling; the egg ribbons and crab are at their best when the broth is gently warm and smooth.

Variations

Vietnamese crab soup has many home and restaurant variations, so the vegetables and garnishes are flexible. For a classic-feeling combination, keep the crab, egg, corn, and mushrooms together. Asparagus adds color and a mild vegetal flavor; if you do not have it, use finely sliced carrot or leave it out. Add firm vegetables with the mushrooms so they have enough time to soften, and add quick-cooking greens near the end.

For a more filling bowl, add ½ cup (80 g) of cooked shredded chicken or ½ cup (80 g) of cooked rice noodles. Add chicken with the crab just long enough to warm it, and keep noodles separate until serving if you want them to retain their texture. You can also use a mixture of crab and small cooked shrimp, keeping the total seafood amount near 8 oz (227 g). Avoid adding raw seafood to this version unless you adjust the cooking process so it is fully cooked.

For a richer soup, replace 1 cup (240 ml) of the broth with 1 cup (240 ml) of unsweetened evaporated milk or light coconut milk. Evaporated milk makes the soup rounder and creamier, while coconut milk gives it a noticeable coconut aroma that is less traditional for many versions of súp cua. Add either gradually over low heat and do not let the soup boil hard. For a lighter broth, use 2 tablespoons (16 g) cornstarch instead of 3; the finished soup will be more brothy and less glossy.

Storage and Reheating

Refrigerate leftover soup within 2 hours of cooking. Transfer it to a shallow, covered container so it cools promptly, and keep it refrigerated for 3 to 4 days. The soup may thicken further as it chills, and the egg ribbons can become firmer; both are normal. For the best texture, store the soup without fresh herb garnish and add new cilantro or scallions after reheating.

Reheat only the amount you plan to eat in a saucepan over medium-low heat, stirring gently and adding a splash of broth or water if it has become too thick. Heat leftovers to 165°F (74°C), checking with a food thermometer, as USDA FSIS recommends for reheated leftovers. Avoid a prolonged rolling boil, which can break up the crab and toughen the egg. You can also microwave a portion in a covered, microwave-safe bowl, stirring partway through and checking the center temperature. Freezing is possible, but the egg and cornstarch-thickened broth may separate or turn grainy after thawing, so refrigeration is preferable for this recipe.

Frequently Asked Questions

Can I use canned crab meat?
Yes. Choose fully cooked crab meat, drain it well, and check for shell fragments before adding it. Lump crab gives the soup distinct bites, while claw meat or finely flaked canned crab blends more into the broth. Since canned varieties differ in saltiness, season the soup at the end rather than increasing the salt at the start.

Can I make the soup without fish sauce?
Yes. Replace the fish sauce with the same amount of light soy sauce, or use a little extra salt if you need to avoid soy. Soy sauce changes the flavor and darkens the broth slightly, while salt alone gives less depth. Add the replacement gradually and taste before serving.

Why did my egg turn into small clumps instead of ribbons?
The soup may have been boiling too hard, the egg may have gone in too quickly, or the spoon may have stirred too vigorously. Lower the heat until the surface is gently moving, drizzle the beaten egg in a thin stream, and use slow, light strokes. Even if the strands are smaller, the soup will still taste good.

Can I prepare this soup ahead?
You can slice the vegetables, measure the seasonings, and pick through the crab several hours ahead; cover and refrigerate them separately. For the best egg texture, cook the soup close to serving time. If you do cook it ahead, cool and refrigerate it promptly, then reheat it to 165°F (74°C) before serving.

What can I use instead of cornstarch?
Tapioca starch is a practical alternative and gives the broth a slightly more elastic, glossy texture. Start with 2 tablespoons (16 g) mixed with ¼ cup (60 ml) cold water, then add more slurry only if needed. Arrowroot can also thicken the soup, but it is best added near the end and should not be boiled for a long time.

Is this soup gluten-free?
It can be, but check the labels on the broth, fish sauce, and any substitute seasonings because formulations vary. Cornstarch is naturally gluten-free, but cross-contact can occur during manufacturing. If serving someone who must avoid gluten, use products specifically labeled gluten-free and avoid replacing the fish sauce with ordinary soy sauce unless it is gluten-free.

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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes

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