By John Gregerson. Assuming it is properly packaged, leftover soup will last 3-4 days. Never remove a large pot of soup from the stove and place it directly in the refrigerator.Large masses of food can take hours--even days--to chill properly.y John Gregerson. Assuming it is properly packaged, leftover soup will last 3-4 days. Never remove a large pot of soup from the stove and place it directly in the refrigerator. Large masses of food can take hours--even days--to chill properly. A slowly cooling medium provides an ideal environment for bacterial growth.