Copyright of recipes

Does anyone know of a definitive, detailed discussion that explains what makes a recipe copyrightable? The guidelines from the Copyright Office are vague (emphasis added):

"Mere listings of ingredients as in recipes, formulas, compounds or prescriptions are not subject to copyright protection. However, where a recipe or formula is accompanied by SUBSTANTIAL LITERARY EXPRESSION in the form of an explanation or directions, or when there is a combination of recipes as in a cookbook, there may be a basis for copyright protection."

This leaves open the question of what's substantial. I'm looking for more detailed guidelines - for instance, a test to determine if I could copyright a recipe for boiling water that consisted of:

Ingredients: 1 cup water

Directions: Heat in a pot until bubbles appear and steam rises from the surface of the water.

Since I've already been through an exhausting argument on the subject, what I'm looking for is an authoritative published source with an answer definitive enough to end the discussion.

Thanks!

Sarah Wernick
70530.435[_at_]Compuserve.com Received on Fri Apr 19 1996 - 15:01:14 GMT