Stable Isotope Analysis of Hydrogen and Oxygen in a Traditional Japanese Alcoholic Beverage, Sake, from Niigata Prefecture in Japan and Other Countries.

Stable hydrogen and oxygen isotopic compositions (δD and δ18 O values, respectively) were analyzed for "sake," a traditional Japanese alcohol beverage, to assess these values for the identification of its geographic origin. We collected sake (Junmai-shu; made of only rice, water, and koji) and its source water (i.e., brewing water) from breweries in Niigata Prefecture, Japan, and measured the isotopic compositions of water in these samples. The δD and δ18 O values for the sake are well correlated with their respective values for the corresponding brewing water (δD; r = 0.92, δ18 O; r = 0.80). Furthermore, based on the δD-δ18 O cross plot, sake brewed in Niigata Prefecture is distinguishable from that brewed in countries other than Japan. These results imply that this dual isotope (δD and δ18 O) analysis is potentially useful in identifying the geographic origin of sake.