Making bright or deep red frosting can be difficult, but the color of the icing will deepen as time passes. It's best to prepare the frosting 24 to 72 hours before you'll need it so the color can set. This is especially important if you want pure red frosting made with only red food coloring, but the same trick can also apply to red variations if they aren't as deep in color as you'd like. When you need to create dark or bright shades of red, the amount of dye used can cause the icing to become bitter.  Taste-testing the icing as you work will allow you to monitor the change in flavor and prevent too much bitterness from developing. If the icing does become bitter, however, you can usually fix it by adding more flavoring. Stick with clear extracts, and use roughly 1/4 tsp (1.25 ml) per 1 cup (250 ml) of icing.

How would you rephrase that briefly using Chinese?
糖霜一定要提前制作。 要不时地尝一尝糖霜。