From Joe Oldaker, Nuneaton, Warwickshire, UK
The extraction of a blue colouring from red cabbage will come as no surprise to many cooks – put red cabbage in a steamer and the water will emerge a deep green-blue 17 April, p 19. Curiously, if you steam broad beans, the water emerges crimson. I wonder whether this food-based colouring has also been exploited.
