the biggest surprise to me as a new circumstantial bread baker is how different the various types of flour are. i always figured because they were all white and powdery that they must be mostly the same, maybe 5-10% in variance, like drive through mass produced lattes from different chains or something. turns out they are VASTLY different and do totally different things.
@sneak You should explore the topic of the biochemistry involved. It is not only the type of flour, but also the type of yeast and other things (for example adding some sugar as additional food for the yeast).
@sneak I'm getting some information from a friend that has interests in the subject. Also English is not our native language.
I've tried to gather some introduction information:
1) https://www.youtube.com/watch?v=y5xOpss4j5E - there is a segment where scientist is interviewed. Explains the basics of making a Sourdough and the general biochemical interactions.
2) https://en.wikipedia.org/wiki/Baker%27s_yeast - basically yeast feeds on sugar and produces CO2 gas
3) https://en.wikipedia.org/wiki/Wheat_flour#W_index - the protein content (this is the most important ingredient of the breads). 9% by weight = 9 gram. So the difference between 9 gram and 13 gram protein content (per 100 grams) is 4 grams or 45%...
I hope this is helpful.