Tangsuyuk (Sweet & Sour Pork)

Variations

• Chapssal tangsuyuk: Add glutinous rice flour for an extra crisp, chewy crust.
• Soy-sauce tangsuyuk: A soy base instead of sweet-and-sour.
• Vegetarian: Tofu, mushrooms, or rice cake instead of pork.
• Poured vs dipped: Sauce poured over (bumeok) for soft, or on the side (jjigmeok) for crisp — your call.

Tips

• Why the starch settles is already explained on this site. Gamja jeon puts it plainly: "starch granules are denser than water and do not dissolve in it, so grated potato left to stand drops its starch to the bottom and leaves water on top. It was never in solution; it was in suspension and it sank." Liangpi uses the same property over a whole night, where the settled starch is not a secret but step one — the sheets are made of nothing else.
• What the settled paste buys as a frying coat is that it has almost no free water. Deep frying says frying trades water for oil, and that if the oil is too cool the steam is feeble "so oil seeps into its place." A thin starch-and-water slurry spends its time boiling that water off; the thick paste left after pouring the top water away sets on contact. That is what gives the thin, glassy shell — and why the guide lists tangsuyuk under "flour plus starch."
• The double fry is in that guide too, and it names this dish. The first fry below 170°C cooks the interior with almost no colour; the second at 180-190°C drives off the last surface moisture and browns it. Do both at once and either the outside burns before the inside is done or you pull it out pale — the same reason karaage is fried twice.
• 1:1 sugar to vinegar is not a preference, it is the dish. Balancing flavour lists tangsuyuk under dishes where the balance is the identity and says outright that the vinegar-to-sugar ratio is the recipe. The same guide sets caponata against it as the opposite construction: tangsuyuk makes a sauce separately, thickens it with starch and pours it over, while caponata boils the vinegar and sugar away onto vegetables that are already cooked. One runs, the other only glosses.
• Poured versus dipped is a matter of taste, but the physics takes a side. The sauce is water, and water softens a starch shell back down. So if crispness is what you want, serve it alongside and eat it straight out of the fryer — a dish with no grace period (serving temperature).
• Glutinous rice flour makes it chewier because of amylose. Daifuku gives the number: ordinary short-grain rice starch is about 17 per cent amylose, glutinous rice has almost none. Amylose is the straight molecule that recrystallises on cooling, so with less of it the crust firms up less and stretches more.
• Coating with settled starch (let it sink and pour off the water) gives the crispest crust — the key trick.
• Double-fry to cook the inside and crisp the outside.
• A 1:1 sugar-to-vinegar ratio is the base — adjust to taste.
• Thicken the sauce well so it clings to the pork.
• If you like it crisp, serve the sauce on the side and eat fresh from the fryer.