Hot water. Buckwheat flour is also known as boiling water dough or hot noodles, under the action of hot water in the flour protein coagulation and decomposition of water, starch absorbs a lot of water to expand into a paste decomposition into monosaccharides and disaccharides, suitable for making steamed dumplings, braised wheat, pot stickers, oil cakes and other foods, buckwheat noodles with cold water will not make the starch solidify quickly, it is easy to appear the phenomenon of noodles overly hard, so buckwheat noodles with hot water and noodles.