" You cannot copyright a list of ingredients but you can copyright the instructions." I'm not disputing the correctness of this but it always seems odd to me. How can Mrs A Cakemaker, writer of cookery books, claim the copyright on the basis of the instructions for a cake which generations of housewives have been making probably for a couple of hundred years and which no-one remembers who invented it.
I make a fruit cake from a recipe that I found in a famous cook's book (no names no pack-drill!). The cake as it came from the recipe she had published in her book was dry, boring and tasteless. I have changed the ingredients and added more, to the point where the recipe and the cake are unrecognisable as the same one, apart from the fact that I use the writer's stated method of making up the cake, which is one that features in almost any cookery book you open. Does that mean that the writer of the book I got the idea from owns my version of the recipe?