Sabrina Pacifici’s 12/27/2020 blogpost at “bespacific” links you to the answer to the answer about “why you can’t copy a recipe book.”
Excerpt, from the beSpacific 2016 Plagiarism Today (PT) blog post:
“…. The reason isn’t because recipe books are lying to you, it’s because, while recipes can’t be copyright protected, other parts of the books can. So, as we celebrate the holidays in the United States, we’re going to take a look at cookbooks and why, even though recipes can’t be copyrighted, you can’t just photocopy and share a cookbook legally….” [Link to beSpacific post.]
Once you have linked through to the PT website / blog, I challenge you to read just one article! They are addictive in the best possible way: after reading one you will feel smarter than yesterday, a worthy goal.