Asked by: Aline Cooper, Chelmsford
Collagen in meat breaks down into gelatine at temperatures between 71 and 96°C.
A stew that’s been bubbling on the stove will continue to break down its collagen for half an hour after you take it off the heat. In the fridge, this will set to a firm jelly and when you reheat it, the gelatine melts to create a silky feel in the mouth. Tomatoes also benefit from long and slow cooking to release flavour molecules within the skin, and a speedy mid-week spag bol won’t have time to reach peak tastiness until it has had those extra hours to marinade. Free water in a dish will tend to soak into starch, taking dissolved flavour with it – pea and ham soup tastes better the next day because the ham stock has been absorbed by the pea starch.
But there’s a psychological aspect too. Chef and food writer James Kenji López-Alt tried to perform scientific comparisons and found little difference when tasting fresh and day-old dishes side-by-side. Perhaps we get habituated to the cooking smells the first time round, and things taste better with a clear nose the next day.