The heat index is rising. The mercury is heading skyward. And we are all searching for ways to cool off this summer. So inevitably our thoughts turn to ice-cream – what could be better? Soft and creamy, pure white with speckles of vanilla bean. Or how about onyx black? In a black waffle cone? It’s this season’s new thing. Activated charcoal, the residue of burning young coconut shells, is the latest secret ingredient to hit the streets. But we wondered how safe is the supply chain and how can we be sure of its purity?