Soy sauce powders were made by spray drying liquid soy sauce using maltodextrin as the drying aid. Three types of maltodextrin, i.e. DE 5, DE 10 and DE 15, were studied and compared. Each type was incorporated into soy sauce with concentration levels of 20% and 40% (w/v), respectively, as a carrier. The spray-dried soy sauce powders were mixtures of amorphous substances and crystalline salts. Caking related properties including particle size distribution, hygroscopicity, glass transition temperature, flowability and caking strength of the powders were characterized. Soy sauce powders produced from the feed solution of maltodextrin concentration of 40% had a larger particle size dispersion, reduced hygroscopicity, higher glass transition temperatures and smaller cohesive index than their 20% concentration counterparts. Maltodextrin of a smaller DE value produced soy sauce powders with less cohesion, higher glass transition temperature and reduced hygroscopicity. Maltodextrin concentration and DE value greatly influenced the caking strength of the soy sauce powders, with different mechanisms and effects under different storage conditions. (C) 2011 Elsevier Ltd. All rights reserved.