There are many recipes for frostings and fillings. But when choosing a recipe to use for a fair exhibit, keep food safety in mind as not all are safe to store at room temperature.
Choose a recipe and get out your calculator! You can determine the safety of a frosting or filling at home. Convert the household measurements into weight for each ingredient. There are many resources to help calculate the weight. See our Food Safety of Frostings and Fillings publication for details. There are examples of calculations to guide you thorough this activity.
For fair exhibits, proof must be given that the frosting or filling recipe contains at least 65% sugar to be deemed safe!