Regarding video recipes: If it looks too good to be true, too easy or too glamorous, it probably is.
There's a lot of extremely popular clickbait videos that pretend to be recipe videos while in fact they are meant to be 'eye candy' to be watched, and the end result if you follow the steps will look nothing like they make it out to be. The videos frequently ...
Here is a small piece of the answer. https://pubmed.ncbi.nlm.nih.gov/33496265/
It is not just yeast strains but especially lactobacillus bacteria that develops and helps to change the ph of the starter. This change in ph is what helps the sourdough bread retain moisture and results in the creation of acetic and lactic acids which create the tanginess.
Many books! Here's a few:
Culinary Reactions is probably the book that most directly addresses your question, since it's specifically cooking and chemistry.
The Food Lab has quite a bit of chemistry in it.
Science and Cooking is both chemistry and physics.
Modernist Cuisine, while about all the new cooking techniques, sure has a bunch of applied chemistry ...