I see a number of blogs/recipes using commercial yeast in the dough and calling it sourdough.
Sorry to break the news to some of us, but if you use commercial yeast, it is not sourdough. I guess someone started this and it kind of stuck with some other people.
Sourdough is made from levain/starter that is a totally natural culture of yeast (and bacteria). If you do not believe me, please check internet and see for yourself.
It somehow hurts me to hear that sourdough culture and commercial baking yeast are equalized. They both are fantastic, yet different. So let’s give them the place they deserve.
Life as I interpret it 
I’ve seen recipes that use sourdough starter with a bit of yeast which is referred to as a ‘hybrid’ bake. Or at least that’s what I call it. 🙂
LikeLiked by 1 person
I am not against using either or both of them in the same recipe. but sourdough should be sourdough.
LikeLiked by 1 person