I was worried this would be another fluff piece, but it's genuinely the most useful reference I own on the subject. As a chef, I appreciated the concrete comparison of granite vs. marble for spice grinding, but the chapters on maintenance and even the business opportunities were an unexpected bonus. The chapter on choosing the right one alone saved me from buying a second, more expensive unit that I would have figured out the hard way. It's the first book I've found that treats the mortar and pestle as serious, professional equipment. I've already recommended it to two of my line cooks.