In a saucepan, combine 1 1/2 cups water, sugar, vinegar, reserved pineapple juice, and orange food coloring. Heat to boiling. Turn off heat. Combine 1/4 cup cornstarch and 1/4 cup water; slowly stir into saucepan. Continue stirring until mixture thickens.
Combine flour, 2 tablespoons oil, 2 tablespoons cornstarch, salt, white pepper, and egg. Add 1 1/2 cups water gradually to make a thick batter. Stir to blend thoroughly. Add chicken pieces, and stir until chicken is well coated.
Heat oil in skillet or wok to 360 degrees F (180 degrees C). Fry chicken pieces in hot oil 10 minutes, or until golden. Remove chicken, and drain on paper towels.
When ready to serve, layer green peppers, pineapple chunks, and cooked chicken pieces on a platter. Pour hot sweet and sour sauce over top.
Crisp morsels of poultry contrast sharply with a glossy, gelatinous sauce that clings without weighing down the plate. Sweet and sour preparations trace their lineage through trade routes linking Cantonese kitchens with global diasporas, eventually adapting to local pantries over generations of cross-cultural adaptation. Maintaining structural integrity requires careful management of thermal energy during frying and precise thickening ratios in the pan.
The Science of the Batter
Coating poultry in a dense slurry containing self-rising flour, cornstarch, and egg creates a protective moisture barrier that shields the interior meat from absorbing excess fat while the exterior dehydrates into a rigid shell. Heat the frying oil precisely to 360 degrees Fahrenheit before submerging the pieces, because lower temperatures allow the batter to absorb oil instead of crisping rapidly. Working in batches prevents the oil temperature from dropping precipitously, ensuring each piece develops a uniformly golden crust instead of steaming itself into a soggy failure.
Balancing Sauce Consistency
Dissolving sugar and vinegar into a boiling base creates the sharp flavor profile characteristic of this dish, which must then be stabilized with a starch slurry to coat ingredients properly. Liquid starches break down if boiled continuously, so stir the cornstarch mixture into the heated liquid only after removing the saucepan from the heat source. Pouring the hot glaze over the fried elements immediately before serving preserves the contrast between the crunchy exterior and the tender meat inside.