Fondant forms cracks due to it drying out, the addition of too much icing sugar or improper handling. Cracked fondant may become difficult to work with. The cracks can ruin the design of your cake, which can make the decorating process a nuisance. While preventing the cracks is ideal, you cannot always avoid cracked fondant. When cracks and tears form in the fondant, repair them to salvage the cake or decoration.
Store unused fondant in an airtight container or store it in cling film. Fondant will dry quickly, and it will begin to crack if exposed to the air for too long.
Knead fondant if you notice cracks forming. The warmth generated from kneading the fondant makes it smooth and glossy again.
Avoid rolling the fondant too thick. Fondant needs rolled to 1/4 of an inch thick for best results. The excess fondant can cause the top of it to form cracks.
Smooth noticeable cracks with vegetable oil or shortening. This will prevent the fondant from dissolving. Apply the shortening in a circular motion with your fingertips.
Soften hard fondant by placing it in the microwave for 5 to 10 seconds.
Never smooth out cracks with water. The water dissolves the fondant. Never store fondant in the refrigerator or freezer. Always store it out at room temperature.