The Step You're Missing For Perfectly White Buttercream

Cake making is a matter of precision and technique. Like the artisans who brought together the Sistine Chapel, so too do home bakers create towering works of beauty and genius. But sometimes, there is just one rusty screw that mucks up the whole business. Take, for example, a white buttercream frosting gone yellow. A yellow tinged buttercream might seem inevitable. The frosting is a mix of butter and powdered sugar (or sweetened condensed milk if you're feeling thrifty), after all. Of course that buttery yellow hue is going to shine through. If you're trying to make a white frosted cake, or white frosted cupcakes, this yellowy tinge is certainly unwelcome, and almost as feared as, say, a crystallized buttercream. There is no need to fret, however, as the solution to your yellow-blues is actually, well, purple!

Adding a small amount of purple food coloring into your buttercream will counteract the yellow tone of your icing, leading to a much brighter, whiter frosting.  Why is this? The answer lies in color theory. Any blonde worth their bottle will know that the key to keeping color bright and clear is purple shampoo. This is because purple lies opposite yellow on the color wheel. So when you add a small amount of purple to a slightly yellow frosting, it eliminates the yellow, making your icing appear perfectly white and crisp. You can also use a white food coloring for the same purpose, though using purple does have a cool, science-experiment feel that will make you feel like an absolute genius in the kitchen.

There are a few tips you'll want to keep in mind when using this trick. After all, color theory can be squirrelly, and correcting a color without adding hue requires some precision. If you add too much purple food dye, your frosting may turn a sickly shade of gray. A safe bet is to start small, and we mean very small. First, mix one drop of purple into your icing. Let your mixer run until the color has completely suffused, this may take a minute or so, and check its color. If it still has a bit of yellow, ad one more drop, and so on. Even so, you may be disappointed with your results, as food coloring can continue to suffuse over time. This means that perfect bowl of white frosting in the bowl may end up looking lavender on the cake. 

If you do end up adding too much coloring, well, there goes your batch of icing! For some it simply isn't worth the effort and risk. So, it's up to you to determine whether or not this hack is worth it. If you're particularly risk averse, you might want to stick to adding white food coloring, or simply settling for a slightly yellow hue in your frosting. The cake will be tasty no matter the color of its frosting, especially if it's flavored with a high quality vanilla.