Wild Fermentation is a popular cookbook written by Sandor Ellix Katz, a fermentation expert. This book explores the world of live-culture foods, including sourdough bread, sauerkraut, and pickles. It provides readers with a comprehensive understanding of the fermentation process and offers a wide range of recipes to try. With its emphasis on natural and traditional fermentation methods, this book is a great resource for those interested in exploring the world of sourdough and other fermented foods.