In the old days (way before the internet), sweet-and-sour was not red in colour at all, as it was predominantly made up of vinegar, sugar and dark soy sauce. However, with the heavy influence Western culture now has, the Cantonese have found that ketchup provides the perfect balance and wrapping consistency for this dish. Who’s to say this recipe upgrade isn’t just as authentic as the old ways? As with any culture as it changes and adapts, it doesn’t make its expressions any less authentic; it just makes them a product of the times.