Why does chocolate turn white?

Published on Doisy and Dam

Picture the scene. It’s an August afternoon: contrary to common remarks from smug Europeans, England is really, inexplicably hot. In the office, Greg’s hogging the fan, and you can’t even throw a stapler at him because company policy dictates that to be wrong and bad. The redemption of lunch is but a distant memory, and dinner is too far away. There’s one thing you need to get you through: chocolate. You make the pilgrimage to the shop, swap your cold, hard cash for some milky cocoa goodness, and prepare to tuck in — but wait. White crap. White crap all over your chocolate. White crap haunting your dreams. Why?

Why does chocolate turn white?

Well, this weird, white-ish coating is called chocolate bloom, and we’re here with some breaking news: it’s not mould. In fact, it’s totally harmless. There are two reasons why chocolate turns white — so slip into your lab coats, friends. We’re about to get sciencey.

1. If chocolate is stored somewhere too humid, the sugar on the surface dissolves and crystallises to produce a dusty effect. This is called sugar bloom.

2. More commonly, chocolate can overheat in summer (relatable to all of us, except maybe Greg the Fan Hogger). When it cools down again, the cacao butter rises to the surface and makes it look cracked. This is called fat bloom.

See? Not crap. Science. And if you are observing the more common fat bloom, you can #MakeChocolateShinyAgain simply by wiping the chocolate’s surface.

So next time you see it, refrain from calling your mum. Appreciate the beauty in the misty chocolate crystals. Get your scoff on, and you’ll find it tastes just as scrumptious as it always did. You’re welcome.

What’s the best way to store chocolate?

While we’re here, the best way to avoid bloom in any chocolate you keep is to store it somewhere dry and cool, between 15-20 degrees Celsius. Naturally in summer months this can be harder, but a low shelf or cupboard is your best bet – even better if it’s in an air-tight container.

To settle the age-old debate, your fridge is actually not your friend when it comes to storing chocolate. Even in a heat wave. Chilling the chocolate in a fridge before exposing it to warmer air when you take it out might just lead to a visit from our old friend, sugar bloom.