“Analytical study shows that the ancient masonry mortar is a kind of special organic-inorganic composite material,” the scientists explained. ”The inorganic component is calcium carbonate, and the organic component is amylopectin, which comes from the sticky rice soup added to the mortar. Moreover, we found that amylopectin in the mortar acted as an inhibitor: The growth of the calcium carbonate crystal was controlled, and a compact microstructure was produced, which should be the cause of the good performance of this kind of organic-organic mortar.”