What causes crab soup to sour?

* Spoilage: If the soup is not properly refrigerated or stored, it can spoil and develop a sour odor and taste.

* Acidic ingredients: Some ingredients, such as tomatoes or lemon juice, can add acidity to the soup and make it taste sour.

* Overcooking: Overcooking the soup can cause the proteins in the crab to break down and release glutamic acid, which is a sour-tasting amino acid.

To prevent crab soup from becoming sour, make sure to:

* Refrigerate or store the soup properly.

* Avoid adding too many acidic ingredients.

* Do not overcook the soup.