Some Physical Properties of Milk. II. Effects of Age upon the Viscosity of Pasteurized Whole Milk

Abstract

Summary A slightly modified Ostwald viscometer is described with which small but definite differences in the viscosity of milk were measured. The increases in viscosity of both nonhomogenized and homogenized pasteurized milk measured at temperatures ranging from 4° to 44° C. as a result of aging or storage of the milk at 4° C. were found to be approximately a linear function of the logarithm of the age. A chart is presented by which the viscosity of milk containing 4.0 ± 0.05% fat and 13.0 ± 0.10% total solids and pasteurized at 62° C. for 30 minutes can be estimated from a known viscosity value at any known age within the age range of 0 to 300 hours. Similar charts can be prepared for milk of different composition and pretreatment.