Unexpected Elements - A sweet treat

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A dip in global cocoa prices got the Unexpected Elements team wondering about chocolate science.

First, we look at how the microbial communities in cocoa beans fine tune the taste of chocolate. Also, could table sugar help us detect the missing bits of the universe? We look at how three elements in sugar were used in the hunt for dark matter.

We’re then joined by Professor of Experimental Psychology Charles Spence, who explains the myriad ways that taste can be influenced – including the shape and name of chocolate, and even the music we listen to as we eat it. Plus, we hear about the rediscovery of a moth in South Africa that was lost to science for 150 years.

And finally, why we cry when we chop onions and the insects that pollinate the cocoa tree. That’s all on this week’s Unexpected Elements.

Presenter: Marnie Chesterton, with Candice Bailey and Sandy Ong
Producers: Sophie Ormiston, with Lucy Davies, Tim Dodd, Imy Harper and Margaret Sessa-Hawkins

Published on Friday, 27th February 2026.

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