Although many proteases can induce the coagulation of milk, most are too proteolytic or have the incorrect specificity and hence can lead to reduced cheese yield and quality. In Ethiopia due to the high cost of commercial rennet, only few dairies manufacture cheese using commercial rennet. Considering the nutritional, economic and value addition importance of cheeses at the same time the unaffordable price of commercially available rennet to most resource poor producers; it is essential to search for locally available and affordable rennet. This book therefore provides information on production of rennet from locally available ruminant abomasums and their effects on Halloumi cheese Yield and Quality. The information reported in this book should be of importance for further investigation and there by making improvement interventions. The Book should therefore be useful to producers of rennet and cheeses, concerned domestic and international research and graduate students.