Violets are blue,
My purple fondant is fading,
Is this happening to you?
I hear these questions on a daily basis - why is my purple fondant fading? What is the best way to make purple fondant? Which pre-made purple fondant is deep purple?
To start, let's begin with a little colour lesson. What is purple? To make the colour purple, you need to mix the primary colours red & blue. Without the colour red, most of your foods would have a greenish or blue tone - grape soda would be blue, deep chocolate cake would have a green undertone, etc.
In order to figure out the purple problem, a little bit of research and history is in needed. Up until the mid 1970's, the red dye used in the food industry was Red Dye #2. In 1976, this dye was pulled from the market as studies had deemed it unsafe for human consumption and could possibly cause cancer. Thankfully there was an FDA approved substitute in place - Red Dye #40. Now manufacturers could continue to colour their products - problem solved - or was it? Well it turns out that Red 40 is not as stable as its predecessor Red 2. And not only that, it was also more expensive and manufacturers require anywhere from 30%-50% MORE colour in order to achieve proper saturation. What does this mean to you? Well it means that the colour tends to fade. You see, the red is a UV intolerant colour, thus UV light (including bright lights) will cause the colour to fade. But how does that affect purple you ask? Remember what I said above? Purple = Red + Blue. If the red fades out, what will remain? BLUE.
So how does all of this information help you? Well now that you know what the causation is, you can look for ways to help prevent it. First, store your purple fondant and gumpaste out of the light - keep it in a dark bag or container and in a cupboard. Also keep your finished cakes, flowers, decorations, etc stored in a dark place in order to help prevent the fading from occurring.
OK so what do you do if you want to display your finished cake or flowers or decorations? Well now you need to look into ways of preserving the purple colour or look for a lasting purple colour. First there is airbrushing. I have found that an airbrushed cake remains true, I have had a purple cake on display for over 4 years and it remains the same.
Another way to have a lasting purple is to use a more stable colourant when colouring your fondant or gumpaste. I have found that the SugarFlair colours are more concentrated and more true, and specifically for purple, the Grape/Violet colour works especially well for a lasting purple. The red they use E122 is much more stable and thus it lasts longer.
Then there is the pH balance. When the pH of your fondant or gumpaste is not balanced, the red can fade out. In order to help counteract that reaction, you can add an alkali such as baking soda. A good ratio is 1 tsp of baking soda per 1 lb of fondant or gumpaste.
Now I'm not a chemist or a colour expert by any means. The above information is simply based upon my own research and experience and is meant to be helpful.
So hopefully the next time you are working with purple, you won't be singing the Blues!