Abstract: An antimicrobial powder, which includes a low molecular weight antimicrobial organic acid and a hygroscopic ingredient, is prepared according to a process wherein the components are combined in a solution to form a liquid slurry composition prior to drying to form a powder, such that drying the liquid slurry composition involves co-drying the components. The low molecular weight antimicrobial organic acid in the antimicrobial powder can be present in a crystal phase of both anhydrous and hydrate forms. The antimicrobial powder exhibits excellent properties, such as shelf stability, without the requirement of encapsulating agents. Methods for preparing the antimicrobial powders as well as applications of the antimicrobial powders in food and beverage products are also disclosed.