Peptone water is a non-selective broth medium that can be used as a primary enrichment medium for bacterial growth. It is a microbial growth medium composed of animal tissue peptate digestate and sodium chloride.

Peptone water is used as a diluent and nutrient enrichment broth for the resuscitation and growth of a wide variety of microorganisms, including Cronobacter, Enterobacteriaceae, Escherichia coli and Salmonella, in all food and feed products and water samples. It is particularly suitable for demanding strains, rigorous growth conditions and difficult protocols.

Peptone water can also be used as a basis for carbohydrate fermentation media. Peptone water can be modified for use in carbohydrate fermentation assays by adding Andrade's indicator. The indicator, which is pink at pH 5.0 and yellow at pH 8.0, is prepared by adding sodium hydroxide to acidic fuchsin until it turns yellow.