Pansies and violas are the two to reach for first. Colorado State University Extension points to large-petaled flowers such as pansies for candying, and the crystallizing method published for home kitchens was written for pansies and violas. That makes them the steadiest edible flowers for cakes to start with. Apple and crabapple petals candy well too. Decorating cakes with flowers takes prep before the sugar comes out, and that prep decides how the finished bloom tastes.
The working list is short. Pansies, violas and Johnny jump-ups sit at the top because they need the least trimming of any bloom here. Roses, dianthus and English daisies belong on a cake as well, and so do marigolds, once you deal with the base of the petal. Calendula rounds it out, and it brings color more than flavor, since the petals were once used as a stand-in for saffron.
Petal size is the thing the guidance keys on. A large petal gives you a surface wide enough to paint and then coat with sugar, and that is the whole reason the same handful of flowers keeps coming up. There is no long list of hidden tests to run. Pick a bloom with real petals to work with, and be sure you know exactly what it is before it goes near food.
Prep comes before the wash and the sugar. Take the sepals off every flower except three. Violas, Johnny jump-ups and pansies keep theirs, so the green cup stays on. On roses, dianthus, English daisies and marigolds, break off the white base of each petal, because that heel is the bitter part. It is slow work with small blooms, and it is the step people skip when the cake has to be done by dinner.
Candied flowers are the finish most people picture. You brush each bloom with a wash made from pasteurized dehydrated egg white, not raw egg, then dust it with superfine sugar while the wash is still wet. After that the flowers just sit and dry, and that stretch takes real time.
Take the sepals off every bloom except violas, Johnny jump-ups and pansies. Break the bitter white base off rose, dianthus, English daisy and marigold petals.
Brush on a wash of pasteurized dehydrated egg white. Raw egg is not what this method calls for.
Coat the wet petals with superfine sugar so the whole flower is covered.
Give them 10 to 36 hours in a dehydrator, or in a 150°F (65°C) oven with the door left ajar.
Move the dry flowers into an airtight container and keep it somewhere cool and dark.
Storage sets how long they hold. An airtight container in a cool, dark spot keeps them waiting until the cake is iced and you are ready for them. These same flowers do more than sit on frosting. They freeze into ice cubes, go into jellies, and fold into pancakes and crepes. Signet marigolds are the best-tasting marigolds of the group, running from bland to a bit spicy or citrus flavored.
Apple and crabapple petals candy well, but the seeds are poisonous and so are plum pits. Keep both off the cake.
Two rules settle the rest of it. Prep the flower before anything else, which means sepals off every bloom but the three that keep them, and the white heel off the four with a bitter base. And never eat flowers from a florist, a garden center, or a nursery. That leaves you what you grew yourself or bought to eat, which is a smaller pool but a safe one for your cake.
Read the full article: Edible Flowers: What to Eat, What to Skip
