An Instron universal testing machine was used to assess fundamental parameters, such as Young's modulus, tensile strength and tensile strain, in order to determine the effect of fat and moisture migration on the mechanical properties of chocolate during storage. Two thin steel anchorages were inserted into each end of the chocolate samples during molding. These anchorages were used to mount the samples in the instrument without inducing stresses prior to the start of the experiment. Longitudinal forces applied to the chocolate provided a measure of the strength of the bond between different chocolate components (nonfat solids and cocoa butter). The new method proved to be a valid technique that can be used to measure fundamental mechanical parameters and quantify the impact of fat or moisture migration. © 2011 Wiley Periodicals, Inc.