Straight and narrow

摘要

Why do some sausages curl when they cook - even those that start off straight? And why do some stay straight such as hotdog sausages? And how can I stop the ones that do curl from doing so, allowing me to brown them evenly? Sausage skin is mostly collagen, which shrinks violently in cooking because it is degraded and dried by the heat. Most cooking to about two-thirds of its length, leaving about 10 centimetres of skewer for a handle.