The effects of storage temperature and humidity were monitored on several physical and chemical components of cowpeas and beans. Seeds stored at 29°C, 65% RH required prolonged cooking times; however, seeds stored in other conditions (5°C, 30% RH; 29°C 30% RH; and 5°C, 65% RH) maintained short, stable cooking times throughout storage. As cooking time increased, phytate, phytase activity, amylose solubility, high methoxyl pectin and protein solubility decreased. Solids leached during soaking and low methoxyl pectin increased as cooking time increased. These results were consistent with the proposed theory that the hard-to-cook defect involves interactions between phytate, minerals, and pectin. However, they did not eliminate possible roles of starch and protein solubility.