Sweet and sour dishes originated from Shandong cuisine. Authentic sweet and sour sauce does not need ketchup. Stir-fry the rock sugar until it is purple, then put 200 grams of aged vinegar into a pot and cook it, then add 150 grams of white sugar, and then add a proper amount of water. After the sugar melts, put the wet starch into the pot several times and thicken a little. Finally, sprinkle the prepared minced garlic into the pot and mix well. The sweet and sour juice without tomato sauce is served.

The ketchup in the sweet and sour sauce was handed down by the southern chef. This is because southern chefs do not have a good grasp of cooking, in order to simplify the practice of sweet and sour sauce.