The invention relates to a method of preparing a liquid oat base having improved smoothness, wherein a material comprising oat bran is suspended in an aqueous media and contacted with α-amylase, β-amylase, β-glucanase, and xylanase to raise the concentration of soluble arabinoxylan by a factor of 5 or more. Also disclosed is a liquid oat base obtainable by the method； a powderous oat base obtained by drying the liquid oat base； uses of the liquid and powderous oat bases and food products comprising them. A powderous composition for use in preparing a liquid oat base comprises oat bran, α-amylase, β-amylase, β-glucanase, and xylanase.
