Shanghai Smoked Fish: Xunyu Without a Smoker

Published by Anthony
on November 7, 2026

Shanghai smoked fish is fried and soaked in a sweet-savoury sauce. Learn a complete xunyu recipe, fish choices, safe cooking and chilling, and serving variations.

Quick Answer: Is Shanghai Smoked Fish Actually Smoked?

Shanghai smoked fish (上海熏鱼, Shànghǎi xūnyú) is usually fried fish coated or soaked in a dark, sweet-savoury sauce. The familiar Shanghai preparation does not require a smoker.^[2][3]

It is often served as a cold appetizer, though warm serving styles also exist.^[2][3]
Firm fish and careful handling help the pieces stay intact.^[3]
A cold serving still starts with fully cooked fish: check 145°F/63°C.^[5]

This guide provides one complete sweet-sour version with fillets; it is not a smoking, curing or shelf-stable preservation method.

Xunyu uses fried fish and a chilled sauce; cook fish to 145°F/63°C, drain before dipping and refrigerate promptly.

Prepare and chill the sauce before frying. Set out clean serving utensils, keeping the dipping sauce separate from the hot-oil station.

Xunyu, Bao Yu and the Shanghai Table

Another name is bao yu (爆鱼, bàoyú). The dish is associated with Shanghai cuisine (本帮菜, běnbāngcài), including festive family meals.^[4]

On Chinese New Year tables it can express nian nian you yu (年年有余, niánnián yǒu yú), the wish for abundance year after year. This is a cultural association, not a fixed menu every family must follow.^[4]

Frying and sauce create the dark surface; no smoking stage is needed.^[2][3]

Choosing Fish and a Serving Style

Choose firm-fleshed fish that can hold its shape. Ask the fishmonger to prepare evenly sized pieces rather than attempting to chop through a whole fish’s spine at home. Carp and pomfret appear in regional recipes, but availability and bone structure affect the choice.^[2][3]

Three approaches illustrate the range:

Chilled soy-sauce style: Fried pieces soak in sweet, dark seasoning and are chilled before serving as an appetizer.^[2]
Warm sauce-coating style: Fried fish is gently coated in heated sauce before cooling for serving.^[3]
Dry-seasoned variation: Jiaoyan (椒盐, jiāoyán), a salt-and-pepper seasoning, coats hot fried fish instead of tangcu (糖醋, tángcù) sweet-sour sauce.^[1]

Ingredients for a Sweet-Sour Version

Fish and oil: 500 g catfish fillets; 4 cups neutral frying oil.^[1]
Spice infusion: 3½ cups water; 3 bay leaves; 1 star anise; 1 piece cassia bark (桂皮, guìpí).^[1]
Seasoning: ⅓ cup rock sugar (冰糖, bīngtáng); 3 tbsp Shaoxing wine (绍兴酒, Shàoxīng jiǔ); 2 tbsp oyster sauce (蚝油, háoyóu); 3 tbsp light soy sauce (生抽, shēngchōu); 1 tbsp dark soy sauce (老抽, lǎochōu); 2 tsp honey; 1 tbsp Chinese black vinegar (香醋, xiāngcù).^[1]

Use a heavy, deep pot with enough headroom that the oil fills no more than half its capacity. Have a frying thermometer, dry long-handled utensils and a clean rack ready. Let bulk oil cool before transferring it.^[7]

How to Make the Sauce, Fry and Coat the Fish

Infuse spices. Simmer water, bay, star anise and cassia 20 minutes; remove spices.^[1]
Reduce and chill sauce. Add sugar, wine, oyster sauce and both soy sauces; reduce about 15 minutes until spoon-coating. Stir in honey and vinegar off heat. Cool promptly in a shallow container; refrigerate until it forms a light glaze.^[1][6]
Prepare fish. Cut fillets into roughly 2 cm pieces and pat thoroughly dry. Keep refrigerated while preparing equipment.^[1][5]
Fry carefully. Heat oil to 375°F/190°C. Fry 1–2 pieces per batch, about 2–3 minutes per side, until browned and 145°F/63°C inside. Drain.^[1][5]
Coat and serve. Dip drained hot fish with tongs into chilled sauce; coat all surfaces. Serve or refrigerate shallow portions promptly.^[1][6]

Hot fish carrying oil can splatter when it meets sauce. Work gently, keep your face away and keep children clear; never pour sauce into the frying oil.^[2]

FAQs About Shanghai Smoked Fish

Do I need a smoker or liquid smoke?

No. These preparations build their flavour through frying and sauce. Adding a smoking stage is a different method, not a requirement imposed by the English name.^[2][3]

Why does the fish break apart?

Very thin pieces and frequent stirring can damage delicate fish. Let a crust form before gently turning, and keep batches small rather than pushing pieces around the pot.^[2][3]

Can the bones be eaten?

Do not assume frying makes bones safe to eat. Check fillets for remaining pin bones, tell diners if using bone-in cuts and remove bones while eating. Check each bite rather than assuming a browned bone has softened enough to eat.

How should I chill and store it?

Refrigerate shallow portions within 2 hours, or 1 hour above 90°F/32°C, at 40°F/4°C or colder. Use within 3 days. Properly cooked and promptly chilled fish can be served cold; if reheating, reach 165°F/74°C.^[6]