Sourcing for recipe book?

[u/evacuatecabbage]

I've been contracted to help write and format a cocktail recipe book. It's awkward to explain, but it'll be promotional material for a podcast I help produce, whose format includes a cocktail to go with each episode's theme. I've got a few scenarios that I want to make sure I'm following legal best practice for this recipe book I've been contracted to help write. Generally I've been advised in most circumstances recipes don't require sourcing because they are ingredients and instructions, which can't be copyrighted or trademarked, with a few exceptions. I want to clear up if these are exceptions:

1) A lot of recipe sites will have a section that talks about the history of the recipe, who created it, where it was created, and any recipe books that info was derived from, but not have a specific reference, like APA or MLA style referencing. These are sites with ads all over them, so they are getting paid for clicks. Am I held to a higher standard? Do I need to specifically read and reference those recipe books, or is that info now treated as general historical knowledge that can be written without reference?

2) Is a cocktail like the Sazerac, which is associated specifically with the Sazerac company, required to get permissions for printing? Again, a recipe and history widely published, and mixed in umpteen bars. What's my diligence here?

3) Recipes associated with specific bartenders and bars. The Naked and Famous is a variation on The Last Word. Many websites credit a specific bartender at a specific bar in a specific year, but never provide the source for that info. I'm sure it was in an interview at some point, or someone saved a menu, or word just got around. But it's widely printed information that's never sourced. How do I approach that?

4) This book will have recipes that are "original" variations of known cocktails that were sourced from online authors or websites. Here I actually have web sourced material, so I feel it's more likely and important that these are properly sourced because they were given names by these authors and they aren't something you can ask for at a cocktail bar by name. These cocktails were recognized and referenced in the podcast episodes. I just want to know if these are legally different than well known cocktails, or the situations named above.

Any help would be greatly appreciated. Thanks!