Gamja jorim (감자조림) is a Korean banchan of small potatoes braised in a soy-based sauce until the liquid reduces to a sticky glaze coating each piece. The potatoes become creamy inside and deeply savory-sweet outside — the contrast between the fluffy interior and the concentrated glaze is why this banchan is ordered repeatedly at Korean restaurants and made constantly at home.
Jorim (조림) refers to the Korean cooking technique of simmering in a braising liquid until the liquid is nearly absorbed or reduced to a glaze. The technique appears across many banchan — jorim of eggs, of lotus root, of burdock — but gamja (감자, potato) jorim is the most universally popular.
The Potatoes
Small potatoes are important. Traditional gamja jorim uses potatoes small enough that each piece is roughly bite-sized (3-4cm diameter, approximately). The ideal is a Korean variety called ja-ban gamja (자반감자) — small, yellow, waxy potatoes that hold their shape during braising without disintegrating.
What to use outside Korea: Small Yukon Gold, fingerling, or baby potatoes work excellently. The waxy texture is important — starchy russet potatoes will fall apart during braising and create a thick, gummy sauce rather than a glaze.
Preparation: If using small potatoes (under 3cm), leave whole or halved. If using larger potatoes, cut into 3-4cm cubes. Peel or leave skins on — both work; unpeeled potatoes have a slightly more textured exterior that grips the glaze better.
Soaking: After cutting, soak cut potatoes in cold water for 10-15 minutes. This removes surface starch that would otherwise cause sticking and cloudy sauce.
Gamja Jorim Recipe
Serves 4 as banchan
Ingredients
- 500g small potatoes (or cubed larger potatoes), soaked and drained
- 3 tbsp soy sauce (ganjang)
- 1.5 tbsp sugar
- 1 tbsp rice syrup (mullyeot) or additional sugar — rice syrup produces a superior glossy finish
- 1 tbsp sesame oil
- 2 cloves garlic, minced
- 1 tbsp neutral oil (for initial browning)
- 100ml water
- 1 tbsp sesame seeds
- 1 green chili or jalapeño, sliced (optional)
For spicy version:
- Add 1 tbsp gochugaru
- Add 1 tsp gochujang
Method
1. Par-cook potatoes.
Two methods:
Method A (microwave): Microwave drained potatoes 4-5 minutes until half-cooked — still firm but no longer raw throughout. This shortens the jorim time significantly.
Method B (direct): Skip this step and add potatoes directly to the pan. Extends total cooking time by 5-8 minutes.
2. Brown potatoes.
Heat neutral oil in a wide skillet or flat-bottomed pot over medium-high heat. Add potatoes in a single layer. Cook without stirring 2-3 minutes until golden on the bottom; turn and brown another 2 minutes. Don't cook through — just develop color.
Browning is optional but adds flavor and visual appeal. Skip for a simpler preparation.
3. Make the braising sauce.
While potatoes brown, combine soy sauce, sugar, rice syrup, and garlic in a small bowl. Stir until sugar dissolves.
4. Braise.
Add sauce and water to the potatoes. Stir to coat. Bring to a boil over high heat.
Reduce heat to medium-low; cover and cook 8-10 minutes, stirring once or twice, until potatoes are completely tender (a knife should slide in with no resistance).
5. Reduce to glaze.
Remove lid. Increase heat to medium-high. Cook uncovered 3-5 minutes, stirring gently but continuously. The liquid will reduce rapidly — watch closely. The sauce is ready when it has thickened to a sticky glaze coating each potato piece and very little liquid remains in the pan.
Glaze test: Scoop a potato — the sauce should cling to it without dripping off. If it's still runny, cook 1-2 minutes more. If the sauce is burning rather than glazing, reduce heat and add 2 tbsp water.
6. Finish.
Remove from heat. Add sesame oil and toss. Scatter sesame seeds. Add sliced chili if using.
The Glaze Science
Gamja jorim's glaze comes from the reduction of sugar-containing braising liquid. As the water evaporates, the sugar concentration increases until it reaches a temperature where it coats the potatoes rather than running off — essentially a diluted caramel behavior combined with the soy sauce's own sugars and proteins.
Why rice syrup? Mullyeot (쌀 물엿, rice syrup) produces a more stable, glossier glaze than sugar alone because it contains long-chain sugars that give a smooth, sticky texture without crystallizing. Regular sugar works but produces a slightly grainy or matte finish at higher concentrations.
Why it matters: A properly glazed gamja jorim looks lacquered — each potato piece dark, shiny, and distinct. Undercooked sauce looks wet and slides off the potatoes. Overcooked sauce becomes hard and sticky.
Variations
Spicy gamja jorim (매운 감자조림): Add 1 tbsp gochugaru and/or 1 tsp gochujang to the sauce. The heat level can be adjusted; the spicy version is equally popular as the mild version. The red chili paste adds both heat and a slightly different sweetness.
Anchovy gamja jorim (멸치 감자조림): Add 10-15 small dried anchovies (myeolchi) to the pan at step 4. The anchovies dissolve into the sauce, adding a savory umami depth without being identifiable. This is a traditional variation that appears frequently in home cooking.
Lotus root jorim (연근조림): The same technique applied to yeongeun (연근, lotus root) — sliced 5mm thick, blanched briefly, then jorim-braised. The lotus root's visual (cross-section holes) and crunchy-when-properly-cooked texture make it a popular banchan alternative with identical sauce.
Storage and Make-Ahead
Gamja jorim is one of the most practical banchan because it:
- Keeps refrigerated 5-7 days (the soy and sugar act as preservatives)
- Improves in flavor on day 2-3 as the sauce fully penetrates the potatoes
- Can be served room temperature or slightly warmed
- Makes well in large batches (scale recipe 2-3× with no technique changes)
Make-ahead timing: For the best version, make gamja jorim 1-2 days before serving. The potatoes absorb more sauce and the flavors mellow and integrate.
Reheating: Reheat in a pan over medium heat with a splash of water, stirring until warmed through and re-glazed. Or serve at room temperature directly from the refrigerator — the glaze is flavorful enough cold.
Gamja jorim is a master class in what jorim does: it turns a very simple ingredient (potato) into something deeply satisfying through the reduction of a seasoned liquid to a glossy, concentrated coat. The technique is more powerful than the ingredients — which is why the same approach works identically on lotus root, burdock, eggs, and fish.
Related reading: Korean Banchan Complete Guide | Sigeumchi Namul Korean Spinach Banchan | Korean Kongnamul Bean Sprout Banchan
The full recipes live in the book.
Get Tokyo Meets Tuscany on AmazonPaperback $24.99 · Hardcover $34.99 · eBook $9.99