After investing their effort in baking a homemade cake from scratch, many bakers are not enthusiastic about tinting their icing with artificial colorings. Red food coloring is especially problematic, both because many diners are sensitive to it and because it has a distinctively bitter chemical taste. A number of natural substances can be used as alternatives to red food coloring, eliminating both the taste and allergy issues. They're not usually bold enough to provide red icing but can yield varying shades of pink.
Hibiscus blossoms have a tart, fruity flavor that's widely used in sauces and herbal teas, where they also create a vividly pink color. The color is soluble in fat as well, and with pink butter, you can make pink buttercream. Melt your butter in a saucepan, and then add half its volume in dried, lightly crushed hibiscus flowers. For example, 1 cup of butter requires 1/2 cup of blossoms. Infuse the flowers in the butter, stirring regularly, until it's strongly tinted with pink. Strain and chill the butter, and then use it as the base for your icing. The color will fade to a delicate pastel as you add sugar.
Red berries can also give your icing a delicate pink hue. Raspberries give a deep red color, needing only to be heated and then strained to remove the seeds and skins. Simmer the juice to concentrate it and achieve a stronger color. Strawberries give a brighter color, but they are less assertive. They work best if simmered and then pureed, and the puree then mixed into the frosting. You'll have visible flecks of strawberry in your frosting. Pomegranate juice falls between the two berries in intensity. It works best if you reduce it to half its original volume, to concentrate the color.
The most potent natural coloring is derived from beets, which are filled with boldly red color molecules called anthocyanins. Chop the beets coarsely and then shred them in your food processor. Squeeze the juice through cheesecloth or a jelly bag to remove the pulp. Simmer the juice until it's reduced to half of its original volume, and refrigerate it until it's needed. Be sure to wear gloves and an apron when you're making the coloring, because beets will stain your clothing and hands. If you want the color without the fuss, beet juice and beet powder are often available at health food stores.
When you use natural food colorings, it's important to recognize from the start that they won't yield the intense color you'd get from a chemical coloring. If you add too much, in search of a more vivid color, you'll ruin the icing. Hibiscus and most berries can only provide the most delicate pastel pinks. Concentrated beet juice or beet powder provides a bolder color. Beet powder leaves a distinct beet-like earthiness in the icing, while the juice does not. It can sometimes have a purple tinge, which you can counter by adding a few drops of lemon juice to the frosting. This reacts with the anthocyanins, restoring their bright red color.
- On Food and Cooking: The Science and Lore of the Kitchen; Harold McGee
- The Professional Pastry Chef; Bo Friberg
- Andrew Olney/Digital Vision/Getty Images