Pempek: Palembang's Fish Cakes and the Vinegar Sauce That Makes Them Addictive

Pempek is the food that Palembang is known for throughout Indonesia, and it's the food that former residents of Palembang take with them wherever they go — making it to order because the commercial versions outside South Sumatra never quite replicate what the local versions taste like.

The combination is specific: a springy, savory fish cake that is simultaneously chewy and yielding, against a cuko sauce that is sweet, sour, spicy, and somehow addictive in a way that's hard to explain until you've eaten it. Together, they create a flavor and texture combination that has no close equivalent elsewhere.

The Fish and the Starch

Pempek is made from ground fish — traditionally tenggiri (Spanish mackerel), which is oily, flavorful, and produces a springy texture. Outside Indonesia, mackerel, cod, or white fish can be substituted. The fish is ground to a paste and mixed with sago starch (not tapioca, though tapioca starch is the common substitution) and salt.

The ratio of fish to starch determines the texture. More fish: more intensely fishy flavor, more tender texture. More starch: springier, chewier, more economical. Authentic pempek leans fish-forward.

Salt is crucial — it denatures the fish proteins during kneading, creating the springy texture. The dough should be kneaded until it no longer sticks to your hands.

The Shapes

Pempek comes in several shapes that affect both presentation and filling:

Kapal selam (submarine): The most famous shape — an egg is cracked into the hollow of a formed fish cake, sealed, and boiled. When you cut into a cooked kapal selam, the runny or soft-boiled egg spills into the cuko sauce. The egg and the sauce is the experience that makes this shape famous.

Lenjer: Long cylindrical rolls, like a thick sausage. The simplest shape; often the baseline form.

Adaan: Round balls, slightly looser dough, sometimes with added spices or coconut. Fried.

Keriting: Flat discs with a crinkled surface that crisps more in frying.

Pistel: Stuffed with papaya filling.

The Cooking Method

All pempek is first boiled in salted water until it floats (about 5–10 minutes, depending on size). The boiling cooks the fish paste and sets the texture.

After boiling, pempek can be:

• Served directly in cuko sauce (the Palembang way for softer texture)
• Fried in hot oil until the outside crisps and the casing turns golden (the way most people outside Palembang prefer)

Fried pempek has a crisp exterior with the soft, chewy fish interior. The contrast with cuko sauce is the point.

The Cuko Sauce

Cuko is the essential component that makes pempek what it is. It is dark, complex, sweet-sour-spicy:

Palm sugar: The primary sweetener — provides the dark color and complex caramel sweetness that refined sugar cannot replicate. Gula jawa (Javanese palm sugar) is the standard.

Vinegar: Creates the sour note. White or cane vinegar.

Garlic: Raw or briefly cooked — provides sharpness and depth.

Fresh chilies: Bird's eye chilies, raw, ground into the sauce. The heat level varies by preference.

Water: To thin to a sauce consistency.

The sauce is cooked briefly to meld the flavors, then the raw garlic and chili paste is added after cooking so they remain fresh and sharp.

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Recipe: Pempek (Makes 20 pieces)

Fish cake dough:

• 500g mackerel or white fish fillet, skin removed
• 175g sago starch (or tapioca starch as substitute)
• 1 teaspoon salt
• 1/2 teaspoon white pepper
• 4 tablespoons cold water

Cuko sauce:

• 200g palm sugar (gula jawa), shaved or chopped
• 300ml water
• 4 tablespoons white vinegar
• 6 cloves garlic
• 5–8 bird's eye chilies (adjust to heat preference)
• 1/2 teaspoon salt

For kapal selam (submarine):

• 6 eggs (one per kapal selam piece)

Method — Cuko sauce (make first):

1. Combine palm sugar and water in a saucepan. Bring to a boil, stirring until sugar dissolves. Simmer 5 minutes. Remove from heat, cool slightly.
2. Grind garlic and chilies to a paste using a mortar or blender.
3. Add vinegar, garlic-chili paste, and salt to the cooled sugar syrup. Taste — it should be a balance of sweet, sour, garlicky, and spicy. Adjust as needed.

Method — Fish cakes:

1. Process fish in a food processor until a smooth paste. Add salt and white pepper.

2. Transfer fish paste to a bowl. Add sago starch and cold water. Knead by hand until a smooth, non-sticky dough forms. This may take 5–8 minutes of kneading.

3. Lenjer (cylinder): Roll portions of dough into cylinders about 15cm long, 3cm diameter.

4. Kapal selam (submarine): Flatten a portion of dough in your palm. Make an indentation; crack in one egg. Seal the dough around the egg completely, forming an oval.

5. Boiling: Bring salted water to a boil. Add pempek pieces; cook until they float, then 2 more minutes. Remove; drain. At this point they can be served in cuko, or cooled and fried.

6. Frying (optional): Heat oil to 180°C. Fry boiled pempek until golden brown and slightly crisped, 3–4 minutes. Drain.

7. Serving: Cut into pieces. Arrange in bowls. Pour cuko sauce generously over. Add sliced cucumbers if desired.

Pempek keeps refrigerated (post-boil, pre-fry) for 3 days, or frozen for 1 month.