Nanban Zuke — Japanese Sweet and Sour Fried Fish
Nanban Zuke — Japanese Sweet and Sour Fried Fish
Nanban zuke (南蛮漬け) is one of my favorite things to make ahead — fried fish marinated in a sweet-and-sour sauce with vegetables that actually gets better as it sits in the fridge. The fish drinks up the vinegar marinade and the flavors deepen overnight, so I often make it the night before and enjoy it even more the next day.
The most common version uses aji (鯵, Japanese horse mackerel) or other small fish — whole or filleted, fried crispy and marinated in the sauce. This time I used kochi (コチ, flathead fish) that I had on hand. Kochi is a white fish common in Kyushu with firm flesh that holds up well to frying and marinating. Any firm white fish or small fish like aji, sardines, or smelt works perfectly for this recipe.
Ingredients (Serves 2–3)
- 150–200g aji (Japanese horse mackerel), whole small fish or fillets — or any small white fish such as sardines, smelt, or flathead
- Salt, to season
- 1/3 carrot, julienned
- 1/2 onion, thinly sliced
- 1 tablespoon potato starch (katakuriko)
- Vegetable oil, for frying
Nanban Sauce
- 2 tablespoons rice vinegar
- 2 tablespoons soy sauce
- 1 tablespoon sugar
- 3 tablespoons water
- 1/2 teaspoon dashi granules
- Dried chilli pepper, to taste (optional)
How to Make It
Step 1: Prepare the Vegetables
Julienne the carrot into thin matchsticks and slice the onion thinly. Keep the cuts uniform so they cook evenly and look good in the finished dish.
Step 2: Make the Nanban Sauce
Combine the vinegar, soy sauce, sugar, water, and dashi granules in a small saucepan. Add the chilli if using. Bring to a simmer over medium heat, stirring until the sugar dissolves. The sauce should smell sharp and tangy — that’s the vinegar doing its job.
Add the sliced onion and carrot to the sauce and simmer for 2–3 minutes until slightly softened. You want them to retain some crunch — don’t overcook. Set aside.
Step 3: Prepare the Fish
The classic fish for nanban zuke is aji (horse mackerel) — small whole fish or fillets work well. I used kochi (flathead) this time, cut into pieces. Whatever fish you use, season lightly with salt and leave for a few minutes. Pat dry with paper towels — removing moisture helps the coating crisp up and prevents oil splatter. Dust each piece with potato starch.
Step 4: Fry the Fish
Heat a generous amount of oil in a frying pan over medium-high heat. Fry the fish pieces until golden and cooked through — about 3–4 minutes per side depending on thickness. The potato starch coating crisps up nicely and helps the marinade cling to the fish later.
Transfer to a wire rack or paper towels to drain the excess oil.
Step 5: Marinate
While the fish is still hot, transfer it to a container or bowl and pour the warm nanban sauce with the vegetables over the top. Make sure every piece is coated. The heat helps the fish absorb the marinade quickly.
Leave to marinate for at least 30 minutes. For the best flavor, refrigerate overnight — the fish soaks up the sweet and sour sauce completely and the whole dish comes together beautifully.
Step 6: Serve
Serve at room temperature or cold, straight from the fridge. Plate with plenty of the marinated vegetables and spoon the sauce over the top.
Tips from My Kitchen
- Marinate while the fish is hot. Hot fish absorbs the marinade much faster than cold. Pour the sauce over immediately after frying.
- It gets better overnight. Nanban zuke is one of those dishes where leftovers are better than fresh. Make extra on purpose.
- Aji is the classic choice. Japanese horse mackerel (aji) is the most traditional fish for nanban zuke — use whole small fish or fillets. Sardines, smelt, and other small fish work just as well. I used kochi this time because that’s what I had.
- Pat the fish dry before coating. Moisture prevents the potato starch from crisping up and causes oil splatter.
- Adjust the sweetness and sourness to taste. Add more vinegar for a sharper flavor, more sugar for a milder one. Taste the sauce before adding the fish.
For other Japanese fish dishes from my Kyushu kitchen, try my mehikari fish karaage (deep-fried whole greeneye fish — a Kyushu specialty) or karei no nitsuke (flounder simmered in soy and ginger).
Where to Buy Japanese Ingredients
If you can’t find these at a local Asian grocery store, here’s what I use:
- Soy sauce — use Japanese soy sauce for the right flavor
- Dashi granules — adds depth to the marinade
- Potato starch (katakuriko) — for coating the fish before frying
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Frequently Asked Questions
What is nanban zuke?
Nanban zuke (南蛮漬け) is fried fish marinated in a sweet, sour, and lightly spicy sauce with thin-sliced onion and chili. The word nanban refers to the Portuguese and Spanish traders who brought the escabeche technique to Japan in the 16th century, which is exactly what this dish is descended from.
What fish works best?
Any small fish you can fry whole or in chunks — horse mackerel (aji) is the classic, and smelt, sardines, or small white fish all work. Firm white fillets like cod are fine too. The fish needs to hold together while it soaks, so very delicate fillets are a poor choice.
How long should it marinate?
At least 30 minutes, but it’s better after a few hours and best the next day. The marinade softens the fish bones and the onion mellows as it sits. Make it in the morning for dinner, or the day before.
How long does nanban zuke keep?
Three to four days in the fridge, and it improves for the first two. The vinegar acts as a preservative, which is why this dish exists — it was a way of keeping fried fish edible before refrigeration. Serve it cold or at room temperature straight from the container.
Can I make it without deep frying?
Yes. Dust the fish in starch and pan-fry it in a shallow layer of oil, or bake it. You lose a little of the crisp edge that soaks up the marinade, but the dish still works — the marinade is doing most of the job.
Nanban Zuke (Japanese Sweet and Sour Fried Fish)
Ingredients
Method
- Julienne the carrot into thin matchsticks and slice the onion thinly.
- Combine the vinegar, soy sauce, sugar, water, and dashi granules in a small saucepan. Add the chilli if using. Bring to a simmer over medium heat, stirring until the sugar dissolves.
- Season the fish lightly with salt. Cut into pieces if using larger fish, or leave whole for small fish. Coat with potato starch.
- Heat a generous amount of oil in a frying pan over medium-high heat. Fry the fish pieces until golden and cooked through — about 3–4 minutes per side depending on thickness.
- Transfer the hot fish to a container and pour the warm nanban sauce with the vegetables over the top. Make sure every piece is coated.
- Marinate for at least 30 minutes — overnight is even better. Serve at room temperature or cold with plenty of the marinated vegetables.
