While it doesn't address your concerns about ethics, recipes are explicitly not covered by US copyright law (obviously there are other factors involved here, bu

While it doesn't address your concerns about ethics, recipes are explicitly not covered by US copyright law (obviously there are other factors involved here, but that's certainly the big one). There may be ethical questions here, but there shouldn't be any legal concerns (IANAL, just a guy in the process of building a site in this space).