"Putting Food By" must be the definitive work on canning, freezing, drying, and preserving food. Do you have a burning desire to can salmon? This book will tell you how. You want to know the exact science behind mold? This book has that information. This book has ALL the information.
If I was solely judging this book on knowledge alone I would give it five stars, easily. But the information wasn't easily read, nor were there any photographs to break up the four hundred plus pages. While this is an excellent reference book on the nuts and bolts of saving food, it is a lousy recipe book to enjoy.