- Milk collected from individual cows (n= 31) was centrifuged to equalize fat composition and was tested during chymosin-induced coagulation to compare the influences of somatic cell level, breed, parity, protein composition, and lactation stage on coagulation rate. Coagulation rate was determined using diffuse reflectance. Pearson correlation coefficients were calculated for all quantitative variables, of which only lactation stage was statistically significant. A student’s t-test was performed to compare coagulation rates between milk with somatic cell levels above and below 200,000 cells per mL. There was no evidence to suggest a difference in coagulation rates between the two somatic cell levels. Coagulation of Jersey milk was significantly faster than Holstein milk. Results from multivariate linear regression identified protein composition and breed as significant predictors of coagulation rate. Initial pH of the whole milk was also significant even though the pH was adjusted to 6.55 for all milk samples. The influence of milk age was also considered, using individual cow milk samples held for zero to five days. Coagulation time did not vary significantly over the five day period. Overall, the results of this study indicate that breed, lactation stage, initial pH, and protein composition significantly impact milk coagulation rate.