Roasting meat sets off a cascade of chemical reactions. With a bit of kitchen chemistry know-how, you can use these reactions to your advantage when you make gravy.

Some coffee lovers can’t do without their hit of caffeine. But if you prefer decaf, here’s the intriguing science of how it’s made, why it costs more – and how much caffeine makes it to your cup.

There are two main methods used to calculate the energy content in food and drinks.