The objective of this method is to determine the viscosity of cereal products containing β-glucan without the need for pretreatments. This measurement is obtained by mixing an aqueous suspension of ground samples with digestive enzymes in a disposable canister in the Rapid Visco Analyzer (RVA). The method can be used in industrial and research laboratories as a screening tool to identify products that may have positive physiological effects. It can also be used as a quality-assurance method to ensure consistency of β-glucan characteristics during production.