Ayib is acid-heat coagulated cottage type cheese popular in almost all parts of Ethiopia. It is made from defatted fermented milk (Arera) after the production butter. It is served with a number of sauses to be taken with either Injera or bread. However, it has a short shelf-life of 2-3 days under room temperature. More shelf-life would mean more income and food from reduced post-harvest loss in milk and milk products for the smallholder milk producers. This book has three parts. The first one reviews previous works on traditional milk processing in Ethiopia in general and Ayib making in particular. Second one describes its traditional processing and quality in Shashemene area, southern part of Ethiopia. Third one is about an experiment made to investigate the role of adding rue and garlic juices on the sensory quality and shelf-life of Ayib. Results presented in this book are first hand information and base both indigenous knowledge and innovative way of enhancing the microbial quality and shelf-life of Ayib.