Simmer down, don’t be the fire-starter: Swetha Sivakumar, on burnt food

When I was in my 20s, living away from home, my mother made all my sambar powder for me, in large batches. “Roast them on low heat, stirring continuously,” she said, tersely. Controlled heat causes chemicals in the spices to combine and morph to form new volatile compounds, giving the mix the aromas and flavours we seek. Apply heat to white sugar too quickly and much of it goes up in a puff of smoke; what’s left is now hard to separate from the pan. But control the heat, and the sucrose molecules eventually begin to break down into volatile ones such as maltol, diacetyl and guaiacol, which give caramel its complex, buttery flavour.