Argh, I just thought about that when I saw you replied to the thread. "I bet he's gonna say a jar." I hate the jarred shit. It's so sour and bitter and not sweet at all. It's fucking false advertising soooo bad. I've tried three or four different brands and they all sucked ass. Serious ass. Like "ew, this is sick!" ass. They overload on vinegar. The closest thing I've tasted to good sweet and sour sauce strangely is Hunt's ketchup. Now I'm not gonna be sticking Hunt's ketchup on my Chinese anytime soon, in fact I don't prefer my ketchup sweet like that (I'm a Heinz girl), but it has a particular sweetness that tastes like it would be great if the components could be isolated for sweet and sour sauce. If I recall correctly, it has more cr0n syrup or something in comparison to other ketchups.
I've been meaning to attempt the sauce from scratch, but I haven't tried it yet. I'm thinking I'd need cr0n syrup, pineapple juice, vinegar, and cornstarch as primary ingredients. I really need to try this. Not now since I'm eating on a budget this month, so maybe next month.
I tried a packet once and to its credit, it wasn't bitter at all. But it still wasn't close enough to what I wanted. I have a cookbook with a recipe for a sweet and sour sauce in it. I haven't tried that yet either.