Twenty-seven barley (Hordeum vulgare L.) samples collected from growing sites in Scandinavia in 2001 and 2002 were examined to study the effect of endosperm structure on malting behavior. Samples were micromalted, and several malt characteristics were measured. Samples were classified as having a mealier or steelier endosperm on the basis of light transflectance (LTm). Because endosperm structure is greatly dependent on protein content, three barley sample pairs with similar protein contents were chosen for further analysis. During malting, the steelier barley samples produced less root mass, but showed higher respiration losses and higher activities of starch-hydrolyzing enzymes. Malts made from steelier barley had a less friable structure, with more urea-soluble D hordein and more free amino nitrogen and soluble protein. The reason for these differences may lie in the structure or localization of the hordeins as well as the possible effects of endosperm packing on water uptake and movement of enzymes.