This is a recipe made by Jenny Tweedie. (@realscotveg on twitter) This according to Jenny may be quite sharp, as the cranberries are an acid fruit to begin with. You can use any vinegar, really, but it should have an acidity of at least five percent. The brown sugar and treacle will give a richer flavour. All chutneys improve with time and you are supposed to leave them for at least four weeks before eating.