You should speak with an attorney on this matter.  It is my understanding that the US Copyright Office has an entire page on recipes and what is and is not copyrightable.  The basic ingredients as well as how to prepare them are not subject to copyright but that does not mean that your book is out there for grabs.  The means you use to convey the recipe is subject to copyright.  So the description for how to prepare the recipe is probably copyrightable under the theory of "original work."  Check out this link.  http://www.copyright.gov/fls/fl122.html