All of the recipes I've tried are very good and seem to adjust well to substitions and experimentation. The only criticism I have is that the book does not adequately explain what the difference is between an amber and a pale or a bock and a stout. Some of them are fairly straight-forward (and my preceding examples probably aren't the best), but when the book calls for an unusual type of beer, I'm left scratching my head. It would have been helpful to state what quality of the beer each recipe benefitted from (thickness, head, hoppy flavor, heavy flavor, etc) so that substitutions of a similar beer could be made.