I’m going to share my most useful hacks for tinting black frosting and other tricky colours like red and navy.
Black frosting is the most common struggle so let’s start with that! There are two secret ingredients here: chocolate chips and cocoa powder. Put the chocolate chips in the microwave for 30 seconds at 70% power. This way they won’t overheat and seize. Then stir the chocolate until it’s smooth with no lumps. Leave it to cool to room temperature.
In a small bowl, add hot water to cocoa powder a little bit at a time. Stir or whisk it until it makes a thin paste with no lumps. I use about 2 tablespoons of cocoa powder and 1 tablespoon of water for every cup of buttercream.
When the chocolate and cocoa are at room temperature, add them to your frosting. I like to do this before adding the milk or cream in my 4 Minute Buttercream recipe. Buttercream made without liquid is much stiffer than it would normally be. The liquid cocoa powder and melted chocolate will thin it out, making it silky smooth and easy to spread or pipe.
Now add black food colouring. I recommend gel colours over liquid colours because they’re much more concentrated. You’ll need a generous squirt of gel but not nearly as much as you’d need if you were using liquid colours. Stir it in and add more if necessary. You’re aiming for a colour that’s darker than grey but not a true jet black.
Cover the bowl with plastic wrap and leave it for an hour for the colour to develop and darken. Tadaa! A true black frosting!
The two hacks for black frosting work for any dark colour of buttercream, like navy blue. Start by adding chocolate to your frosting to darken it. Ideally add melted chocoalte and cocoa powder but you can use one or the other if you don’t have both. The darker the brown you start with, the less colour you’ll need to add later.
Adding just blue to brown will make a fairly dark blue but to make navy, add some black as well. Alternate between adding blue and black until the colour is almost as dark as you want it to be. Cover the bowl with plastic wrap, leave it for an hour and voila! A beautiful deep navy buttercream!
If you're struggling to achieve the colour shown on a bottle of gel, you're probably not using enough gel. Gels are concentrated but you do need to use a generous amount for really bright and bold colours, juts like you do for black frosting.
Covering the bowl and letting the frosting rest gives any gel colour a chance to develop. This will make your colours brighter and bolder within about an hour. Look at the difference between this frosting immediately after adding colour and after an hour of resting:
Red frosting can be tricky but just like any other colour, start by using a good amount of gel. Then you can make red frosting brighter by covering the bowl to let it rest for an hour. Another hack that works really well with red buttercream is to heat it. This works for other colours like black frosting but I find it the most effective with red frosting. Scoop up no more than a third of the buttercream and microwave it for 10 seconds. It will melt and get much darker.
Add the melted buttercream to the rest of the red buttercream and mix it together. It will look grainy at first because of the melted butter. Leave it to come to room temperature or speed up the process by putting it in the freezer for 5 minutes. The result will be a beautiful deep red frosting that’s silky smooth.
A common question is how avoid the bitter taste caused by using lots of gel. As well as limiting the amount of gel you use by using these methods, here's another trick. After tinting your frosting, add clear-coloured flavour to it. You can use clear vanilla or almond extract or even other flavours like lemon or mint (depending on the flavour of your cake of course!) The flavour will disguise any taste of the gel in the buttercream.
All I taste in this cake is almond flavoured red frosting and my deliciously moist Perfect Chocolate Cake!
I hope this tutorial has been useful! I share everything I know about buttercream in my online MasterCourse, The Basics of Buttercream, including how to:
Visit my online cake school to take the course or sign up for my ClubPLUS membership for access to every MasterCourse, MiniCourse and Live Workshop!
You can also watch a video tutorial on how to make black frosting and other tricky frosting colours!