B543 KAKUREI Koiai-iro 鶴齢 濃藍色 山田錦 (生原酒) 青木酒造 新潟県 R7BY 720ml

[New Kakurei - Koiai-iro]

Aoki Shuzo has made a move. The Kakurei limited-brewing series will be completely renewed. This is more than just a rebranding—it’s something that could influence the entire sake industry. The impact could be significant, potentially reshaping long-held conventions within the world of Japanese sake. Aoki Shuzo may not be a large manufacturer, but it’s a highly respected producer whose influence is widely recognized.

First, the indication of the production date has been removed; only the brewing year is stated. The label also no longer shows the polishing ratio that everyone loves to check. Therefore, it’s impossible to tell whether this sake is a Daiginjo, a Junmai Ginjo, or a Junmai. The name of the sake rice used is listed—it’s Yamada-NIshiki. There’s no need to spell out Aoki Shuzo’s intention; you’ve probably guessed it already.

Instead of focusing on technical details, Aoki Shuzo invites the drinker to imagine and interpret. The sake’s name bears that of a traditional Japanese color, and the name “Kakurei” is written in yosemoji calligraphy—the lettering style used for vaudeville playbills since the Edo period. This particular sake is called Koiai-iro, and that color is used on its label.

Upon close inspection of the actual label, you'll notice its remarkably high quality. This series consistently employs traditional Japanese colors, and it's evident that achieving these subtle hues required sophisticated attention to paper quality, printing techniques, and other advanced elements.

Now, what kind of flavor do you imagine from this label? Feel free to savor it first with pure intuition—or dive into the story of Koiai-iro afterward—for an even more profound experience.

[Koiai-iro]

Koiai (or Koai. "deep indigo") is one of Japan's traditional colors, representing the darkest stage of indigo dyeing—an extremely deep shade of blue reminiscent of a profound night sky or richly layered indigo fabric, with a serene and elegant blue-purple hue.

Koiai appears in the Engishiki, a comprehensive 50-volume legal code compiled in the mid-Heian period (10th century) that details the implementation rules (manual) for the ritsuryō system. Commissioned by Emperor Daigo in 905, it was completed in 927 and enacted in 967, meticulously recording ancient government structures, rituals, and annual court events—making it an indispensable national treasure for ancient Japanese history research.

In the official and ceremonial world defined by the Engishiki, colors were not mere decoration but essential elements for distinguishing attire and maintaining order. Koiai, as the deepest stage of indigo dyeing, was understood to symbolize calmness, dignity, and purity. The indigo color hierarchy included stages such as Koisi (deep indigo), Nakaai (medium indigo), Asaai (light indigo), and Shiraai (white indigo), with koiai at the pinnacle, denoting the highest level of prestige.

Koiai in the Engishiki served as the supreme indigo shade, enforcing hierarchical order in courtly robes through its profound depth and noble connotations—bridging aesthetics, ritual, and social rank in Heian Japan.

During the mid-Edo period, with the widespread adoption of cotton fabrics and advancements in indigo dyeing techniques, koiai began to be used in everyday commoner life. Indigo adhered exceptionally well to cotton, producing durable and practical results, which led to its permeation into clothes, daily tools, and noren curtains. Thus, koiai and other indigo shades have endured as quintessentially Japanese colors, beloved to this day.