Whether you're icing a Little Red Riding Hood cake or you want an authentic gore scene for horror film night, you'll need dark red food colouring. The standard set of food colouring offers four choices: red, yellow, blue and green. As with any dark colouring, taste can suffer. If you've ever eaten an Elmo cake, you know that red icing can taste bitter. Protect your food's taste by using dark red food colouring sparingly.
Create a small pool of black food colouring by mixing one drop each of yellow, blue and red on a small white plastic or paper plate. Mixing any colouring with a little black darkens the original colour.
Dispense a single drop of red food colouring into your second mixing dish. Using white surfaces for mixing allows you to see the colour in its truest form.
Add 1 drop of black colour to your red drop using the eye dropper. Mix the two colours with a small spoon.
Mix half a spoonful of whichever food (icing or batter, for example) you intend on colouring with the dark red dye. This gives you a preview of how the 1:1 ratio of red to black colouring will appear in your food.
Create a darker red by adding an additional half-drop of black or make a brighter red by adding an additional half-drop of red. Write down the total number of drops each time you add more so you can easily recreate that same colour later.
Different icings or foods respond differently to dyes. Complete a test batch of each food you intend on colouring before mixing half the bottle of food dye.
Dark red food colouring can stain your fingers and clothing. Wear an apron, food-safe gloves and mix your colours over the sink.