I really enjoyed Home Coffee Roasting by Kenneth Davids: https://www.amazon.com/Home-Coffee-Roasting-Revised-Updated/dp/0312312199 https://www.amazon.com/Home-C

I really enjoyed Home Coffee Roasting by Kenneth Davids: https://www.amazon.com/Home-Coffee-Roasting-Revised-Updated/dp/0312312199 https://www.amazon.com/Home-Coffee-Roasting-Revised-Updated/... It's not about grinders but it spends a few chapters on how coffee is produced and how different factors/regions can affect its flavor. It's an excellent primer on coffee in general, and of course on roasting at home (though the chapter on machines at the end is a little outdated).