In addition to naming the letter, the older child can make the sound the letter makes. Encourage the child to name a word that begins with the letter as he or she uses a spoon to pull a specific letter from the soup.
Young children may begin by making the soup and simply recognizing the concept of a letter. They often begin letter recognition with the first letter of their first name. Fix the child a bowl of “Mary” soup (using his or her name) by spooning the M from the soup and putting it in a bowl.