Abstract: The low temperature stability of an additive product for imparting desirable properties such as water repellency, set-retardation, etc., to hydraulic cement compositions and Portland masonry cements in particular, is improved by the addition of a small amount of certain low molecular weight, water soluble, non-ionic organic materials (e.g. alcohols, ketones, amides, and aldehydes) to the additive product. The use of low-temperature stabilizers within this class which also act as grinding aids for hydraulic cements (e.g. glycols) is highly preferred, since the use of such materials as the stabilizing ingredient has been found to additionally impart grinding aid properties to the additive product even at the relatively low usage rates of the stabilizing component. This additional property of the resulting product is a very desirable advantage to the user of the product since the product is customarily added to the cement during the grinding operation.