This book is an authoritative deep dive on Tempeh. It is referenced in many other books and studies. It tells a lot about the tempeh making process, different type of tempeh, etc. It is very helpful if you want to make your own tempeh, and gives you a lot of information about what to expect, and how to prepare it, about the edibility of over and under done tempeh, and how to use it, the history of tempeh, etc. (It fails to mention that tempeh bongkrek, coconut tempeh, if contaminated, can be extremely poisonous, and kills many people annually. As far as I can tell, other types of tempeh are pretty safe. This is something I think people would want to know before they start experimenting. )The book has some confusing but interesting information about tempeh as a great vegan source of vitamin B12. B12 is extremely high in tempeh made in Indonesia because of contamination of the tempeh. Unfortunately, tempeh made in the US is not particularly high in B12, as it lacks this bacterial contamination. Thus the authors are actually speculating about making tempeh a great source of B12 at some future date. This was somewhat disappointing, as as far as I can tell, this has not yet happened.The book is somewhat problematic as a tempeh cookbook, as many of the recipes require Indonesian ingredients which are not readily available. It turns out that Indonesian recipes also usually involve deep fried tempeh, although the authors offer alternatives which they say are not as good. I agree, they aren't, although I still use the alternatives. I wonder how an air fryer would work, but don't have one. It looks like the original book was written in 1941, long before air fryers. Because of the age of the book, it is hard to know whether one can rely on some of the statistics they give about soy and world hunger. This was written well before GMOs, and expensive organic soybeans.There are some good recipes in the book which can be made from readily available ingredients, such as coriander and garlic crisp tempeh. That recipe involves a basic preparation technique, which is simple and may be worth the price of the book. I am happy to have the book, but would not recommend it to the average person who just wants some tempeh recipes and does not plan to make the tempeh themselves unless they live near an Indonesian grocery store.