On the thirtieth of June 2021 the sake of Nagano was designated a geographical indication, on the same day as the prefecture's wine. It was the tenth such designation for sake in the country.

The application came from the sake and shochu committee of the prefecture's own appellation control body, an organization run by producers, with the wine committee filing alongside it on the same date in April of that year.

The production standards come down to three things. The rice must be one hundred percent grown in Nagano, and the variety is not specified. The water must be drawn within the prefecture. And everything from milling the rice through fermentation, storage, bottling, and shipping must take place inside Nagano.

Then there are two examinations. A document review confirms that the sake was made to the standard. After that a sensory panel tastes it and scores four things: aroma, flavor, balance, and the whole. What the rules are indifferent to is which rice was used. What they are strict about is where every stage of the work happened. Anyone who wants the name has to satisfy both the paperwork and a panel of mouths. The place is the requirement, and the rest is left open.