Select both sweet and sour guavas. The sour, for acid and pectin essential to a good jelly; the sweet, for flavor. Do not cook more than 3 pounds of guavas at a time.
Wash guavas thoroughly. Peel and reserve peelings. Cut guavas in halves and remove seeds carefully, without breaking shells. Reserve guava shells to make Guava Shells in Syrup. Combine peelings and seeds with water included in A and cook over moderate heat for 1 hour, stirring occasion