I’m often asked about chocolate bloom. What is it? Is it harmful? What causes it? So here’s a post dedicated to answering your bloom-related questions. Most people think it’s unsightly (and on fresh chocolates it rings alarm bells), but I think it can be a beautiful and intriguing sight. Doesn’t it look like something you’d expect in a petri dish?
However, it’s not something you want to see on your chocolate!
What is bloom?
Bloom is what happens when chocolate is exposed to heat fluctuations or moisture. It’s that crumbly white appearance you sometimes see on the surface of chocolate. Some people mistake it for mould, but it’s perfectly harmless. There are two kinds of bloom.
Sugar bloom occurs when chocolate is exposed to humidity or moisture. The sugar within the chocolate dissolves on contact with tiny water droplets in the air. When the water on the surface of the chocolate evaporates, small sugar crystals are left on the surface of the chocolate, giving a dusty appearance. This is why chocolate should not be stored in the fridge!
Fat bloom can happen for a number of reasons (including if the chocolate is untempered or incorrectly tempered), but commonly occurs if chocolate is stored in fluctuating temperatures. When chocolate is left in a warm place and starts to melt, the cocoa butter (the fat) within the chocolate separates from the rest of the ingredients, rising to the surface. Once it has cooled again and re-set, this gives the chocolate a mottled appearance. The picture above is of melted, untempered chocolate that has developed some serious bloom!
This is why it is important to store your chocolate in a cool, dry place, and it also demonstrates the importance of tempering! If you’d like to learn how to temper chocolate, find out more about our chocolate-making workshops.