Abstract Most of the milk consumed by humans comes from cow’s milk. The processed products are cheese as a result of the separation between whey and curd through the fermentation process. This process involves microbial activity that takes place in aerobes and anaerobes. Making cheese involves the process of clumping milk with helping of the rennet enzyme. There are difficult to obtain and the price is relatively expensive. So that a replacement for this enzyme is needed. Ceremai fruit extract can be used in the process of milk clotting. The research aims to find the concentration of it which optimally influences the clotting process of FH (Friesh Holland) cow milk in cheese making from the time of clumping. It is obtained by blending until smooth, then poured into a filter and squeezed to get extract. The extract was used for 5 treatments with a concentration variation of 50%, 60%, 70%, 80%, and 90% with 5 repetitions. The results showed at the concentration of 90% produces the optimal clumping time with an average clumping time of 5.4 minutes. So influences the time of clumping of cow’s milk in making cheese and it can be used as an alternative ingredient for rennet enzymes.