Abstract Mozzarella cheese was manufactured to contain up to 50% less fat than conventional part-skim Mozzarella cheese. Milk, which had been standardized to a casein to fat ratio of 1.2, 1.6, 2.0, or 2.4, was inoculated with single strains of Lactobacillus helveticus and Streptococcus salivarius ssp. thermophilus. A new manufacturing procedure was used to retain moisture in the cheese as fat percentages decreased and protein increased. Stretch, melt, and cook color were evaluated at 1, 7, 14, and 28 d during storage at 4°C. Analysis of variance showed no significant differences in stretch, melt, or cook color between cheeses with different casein to fat ratios. Cheese made with a casein to fat ratio of 2.4 retained more stretch over 28 d than did cheese with lower casein to fat ratios. Stretch decreased and melt increased significantly for all cheeses during storage for 28 d. The stretch and melt characteristics of Mozzarella cheese containing up to 50% less fat were similar to the part-skim Mozzarella reference cheese.