# Crispy Sweet and Sour Pork

Sweet and sour pork is crisp, golden bites of pork tossed in a glossy, tangy sauce with pineapple and peppers. It is a takeout classic you can make at home with a bottle of oil and a few pantry sauces.

The secret is frying the pork twice for a crust that stays crunchy, and adding the sauce at the last second. Serve it right away with steamed rice.

- Total time: 40 min (prep 20 min, cook 20 min)
- Serves: 4
- Per serving (estimated): 520 kcal, 29 g protein
- Cuisine: Chinese. Category: Main course. Diet: dairy-free.

## Ingredients

- 500 g pork loin or tenderloin, cut into 1-inch (2.5 cm) cubes
- 1 tbsp soy sauce
- 1 egg white
- 1/2 cup cornstarch, divided
- 1/4 tsp salt
- 250 ml neutral oil, for frying
- 1 red bell pepper, cut into 1-inch (2.5 cm) pieces
- 1/2 onion, cut into wedges
- 1 cup pineapple chunks (about 160 g)
- 60 ml ketchup
- 3 tbsp rice vinegar
- 3 tbsp sugar
- 60 ml pineapple juice
- 1 tbsp soy sauce, for the sauce

## Method

1. Toss the pork with 1 tablespoon soy sauce, the egg white and the salt. Add 6 tablespoons of the cornstarch and stir until each piece has a thin, sticky coating.
2. Whisk the ketchup, vinegar, sugar, pineapple juice and the second tablespoon of soy sauce in a bowl. Stir the remaining 2 tablespoons cornstarch with 2 tablespoons cold water in a separate small bowl.
3. Heat the oil in a wok or 12-inch (30 cm) deep skillet to 350°F (175°C). A pinch of cornstarch should sizzle at once.
4. Fry half the pork for 3 to 4 minutes, turning once, until light golden and cooked through to 145°F (63°C). Drain on a wire rack. Repeat with the rest.
5. Reheat the oil to 375°F (190°C) and fry all the pork together for 45 seconds, until deep golden and very crisp. Drain again.
6. Pour off all but 1 tablespoon oil. Stir-fry the pepper and onion over high heat for 2 minutes until just tender but still crisp.
7. Add the sauce and pineapple and bring to a simmer, 1 minute. Stir the slurry, add it, and cook 30 seconds until glossy. Fold in the pork, toss for 10 seconds, and serve immediately over rice.

## Why it works

- A thin coating of egg white and cornstarch forms a crisp shell that seals in the pork's juices.
- Frying twice, first to cook the pork and then to crisp it, drives out extra moisture and keeps the crust crunchy in the sauce.
- The sauce balances sugar, vinegar and ketchup, so it is sweet and tangy rather than just sweet.
- Stir-frying the peppers briefly over high heat keeps them bright and crisp.
- Tossing the pork in the sauce at the last second keeps the crust from turning soggy.

## The science

- **Double frying.** The first fry cooks the pork and sets the crust. During the rest, moisture from inside moves outward. The second fry in hotter oil drives off that moisture, tightening and crisping the crust so it survives a coating of sauce.
- **Balancing sweet and sour.** Sugar and vinegar work in opposition. Acid cuts the perception of sweetness, while sugar softens the sharpness of the vinegar. A good sauce sits where neither dominates, and tasting before thickening lets you adjust it.

## Tips

- Make sure the pork is dry-ish and well coated; too much liquid makes the crust gummy.
- Keep the oil temperature steady by frying in two batches.
- Have the sauce and the vegetables ready before you do the second fry.

## Mistakes to avoid

- Saucing the pork too early, which turns the crust soggy; toss at the very end.
- Frying cold pork in cool oil, which makes it greasy; check the oil temperature.
- Overcooking the peppers, which makes the dish limp; give them 2 minutes in a very hot pan.

## Variations and swaps

- Use boneless chicken thighs, cooked to 165°F (74°C), for sweet and sour chicken.
- Add chunks of cucumber or carrot for color.
- Add a spoon of chili garlic sauce for a spicy twist.
- Swap rice vinegar for white vinegar, using 2 tablespoons.
- Swap pineapple juice for orange juice for a milder sweetness.
- Swap pork loin for pork shoulder, cut into smaller pieces and fried 1 to 2 minutes longer.

## Storage

Store the sauce and the fried pork separately in the fridge within 2 hours and eat within 3 days. Reheat the pork on a rack at 400°F (200°C) for 8 minutes, then toss with warm sauce to 165°F (74°C).

## FAQ

**How do I keep sweet and sour pork crispy?**

Fry the pork twice and toss it with the sauce just before serving. The double fry removes more moisture so the crust stays crunchy for several minutes.

**What is in sweet and sour sauce?**

A classic version has ketchup, vinegar, sugar, soy sauce and pineapple juice, thickened with cornstarch. The balance of sweet and sour is adjusted to taste.

**Can I bake sweet and sour pork instead of frying?**

Yes. Coat the pork in cornstarch, toss with oil, and bake on a rack at 425°F (220°C) for 20 minutes, flipping once. It will be crunchy but less shatteringly crisp.

**What cut of pork is best?**

Pork loin or tenderloin cut into cubes works well. Pork shoulder is juicier but needs a little longer in the fryer.

**What temperature should the pork reach?**

The USDA safe temperature for pork is 145°F (63°C), with a rest. With 1-inch (2.5 cm) cubes, 3 to 4 minutes in 350°F (175°C) oil gets there.

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Source: https://cookingscientist.com/recipes/sweet-and-sour-pork (Cooking Scientist). Learn the science of cooking in the Cooking Scientist app for iPhone and iPad: https://apps.apple.com/app/id6830326846