Spread it on a tray and dry in the sun or food dehydrator. Store in airtight container. Crystallizing Crystallizing fruit is one of the oldest methods of food preservation known to man. Citrus fruits have pronounced and varied flavors that make them ideal for crystallizing. Thick-skinned fruit is best.
Crystallization is the process of saturating fruit with sugar.
To do this, fruit is placed in boiling syrup and cooked gently. The heavy syrup will cause the water to be drawn from the fruit more quickly than the sugar will be absorbed, and the cell walls of the fruit will become shriveled and hardened. Several crystallizing methods may be used. Crystallized fruits may be stored at room temperature for up to four months, or frozen for longer storage. Jelly and Marmalade Citrus fruits are ideal for many types of jellies, marmalades and sweet spreads because both acid and natural pectin content are generally high.