A toasting appliance includes a toasting chamber, a heating element arranged to heat a foodstuff located within the toasting chamber, and an optical system for optically illuminating the foodstuff and detecting light reflected from the foodstuff. Before the foodstuff begins to change colour as a result due to the heating thereof by the heating element, a controller varies the illumination of the foodstuff by the optical system so that the intensity of the light reflected from the foodstuff is at or around a set value. The controller subsequently terminates the toasting operation when the intensity of the light reflected from the foodstuff has reduced, due to toasting thereof, from the set value by an amount depending on a desired degree of toasting of the foodstuff.