Afikomen: The Custom of Many East European Jews
"Many East European Jews, and their descendants, follow the custom of saving a piece of the afikomon. They tuck it away in a drawer, and leave it there until the next Passover, a year later, when it is replaced with a new piece.
This custom developed in commemoration of the verse in Deuteronomy (16:13), `that thou mayest remember the day when thou camest forth out of the land of Egypt all the days of thy life.'"
(The Family Seder. Prepared by Rabbi Alfred J. Kolatch. Jonathan David Publishers, Inc. Middle Village, New York. 1991 by Alfred J. Kolatch)