Hi, I hadn't published any Dan Lepard recipes so I've not received a rocket from David Whitehouse however it's me who organises the Nigella blog event linked to above and I wrote those guidelines re changing at least two ingredients and writing your own method. These guidelines were based on advice received in the recipe copyright sessions at Food Blogger Connect conference given by a food blogger who happens also be an lawyer practicing in intellectual property rights - so I trust her stance!
There is no copyright granted to recipe ingredient lists as there is no artistic expression associated with them. The wording of the directions however does require artistic expression hence it is the directions that are covered by copyright not the list of ingredients.
If you take a published recipe and tweak it to suit yourself, re-write the directions and vary some ingredients then it effectively becomes a new recipe for which you have the copyright.
If you publish/blog a recipe that is very obviously inspired by someone else, it is polite to say your recipe was "inspired by" or "adapted from".
Think how many Victoria sponge or shortcrust pastry recipes there are, noone has copyright of these recipes however the flowery Nigella wording is her own artistic expression and should not be reproduced elsewhere.
Where the Dan Lepard thing has got murky is that his manager has been arguing with some food bloggers that they've breached Dan's copyright if they've adapted his recipes. This is highly wobbly ground because there is no copyright over ideas but most food bloggers have taken recipes down on David's request even if they don't agree with his argument.
Probably if you googled the recipe names in Dan's short and sweet book you'd find the majority had been made by someone somewhere before he published them - Weetabix Muffins for instance were published in the early 2000s by an American site.
My advice is:
- For recipes directly copied from books, just link to either the book on Amazon or somewhere legitimate that has published it with permission elsewhere.
- For recipes you are making up or adapting, compare 2 or 3 versions elsewhere and develop ingredients that are a hybrid of what you've seen done in a few other places. Then write your own words.
Hope that helps!