This product is amazake made by mashing rice jiuqu and making it smooth. "Hakuho no Shio" is used, and it is said that the mild salty taste without horns brings out the characteristics of sake lees and jiuqu.
By the way, amazake is a beverage that can replenish the "moisture and salt" lost by sweating and the "sugar" that is the energy source for the body. In modern times, it is often seen in winter, but in fact it has been drunk as a "summer heat countermeasure" since the Edo period, and it is also used as a "summer season word" in haiku.