Acetic Acid 30ml – 30% food grade – 3 drops added to a batch of Royal Icing will make it more pliable and quick drying.
Recipe for Royal Icing with Acetic Acid (perfect for piping)
1 1/4 to 1 1/2 cups pure icing sugar (never use icing mix!)
1 egg white
2 to 4 drops acetic acid
Sift icing sugar and then measure the amount required. Beat egg white lightly using a wooden spoon. Add sifted pure icing sugar 1 tablespoonful at a time, beating well after each addition. When icing reaches the desired consistency, add acetic acid, beat well.
The amount of icing sugar required depends on size of egg-white, and consistency required.