Shriveled kernels lower wheat test weight and reduce milling flour yields. Test weight is also lowered by rain-dry cycles that cause kernels to puff (exhibit, in part, loosened layers of pericarp). A numeric score was developed for degree of puffing and for degree of shriveling based on simple measurement devices. Wheat samples were evaluated for test weight and Single Kernel Characterization System (SKCS) hardness index, SKCS kernel weight, milling flour yield, and kernel density (hexane displacement). 

Those evaluations were performed before and after samples were air-aspirated to remove all shriveled kernels. Test weight, SKCS hardness index, and density of aspirated samples were used to develop a puffing score. Changes (resulting from aspiration) in test weight, SKCS kernel weight, and flour yield were used to develop a shriveling score. Higher puffing scores were related to elevated alpha-amylase activity. Puffed kernels were softer and were not associated with decreased flour yield. Puffing and shriveling scores were independent (poorly correlated), but together predicted 95% of the variation in original, non-aspirated test weight.