Sourdough.
What to they actually mean by that, when applied to bread?
Almost every commercial 'sourdough' I have ever tasted is a hybrid, with a whiff of levain and a portion of commercial yeast.
Is there any rule about what percentage of actual levain starter needs to be used before it can be labeled sourdough?
Some products seem to have had no more than a cursory whiff of the stuff.
I became aware of this when I started giving away my bread, which is 100% levain-based, a true sourdough.
I got some feedback that it was a bit 'tangier' than they were used to.
This was mostly not a complaint, just an observation.
But I've had to revert to a hybrid mix for a couple of people.