Book about Levain and starter maintenance - maybe french?

Hi All,

This is a stab in the dark. I think I remember reading about a French book all about different types of sour starters. How to change it for different types of bread and how things like less water aids yeast development. And more water develops this or that.

I remember thinking that would be good, if I could speak French! But now I have been learning French so I thought I'd try to track it down.

The question is- did I imagine the whole thing? Or do you do know a different book? I guess, I'd love to know more about mashes or highly acidic German starters (that's still a mystery to me).

Thanks Brains-trust!

Fiona