Have you ever bitten into an astringent persimmon? The tongue-tingling bitterness comes from tannins (the main component being shibuol) that are dispersed in a soluble state within the fruit. All persimmons contain tannins, but the tannins in sweet persimmons are clustered in particles, making them insoluble, so you don’t taste the bitterness.
The "kaki-shibu" I will talk about from now on revolves around these tannins.

Do you know what persimmon tannin is?

The term "kaki-shibu" itself may be unfamiliar to some. It refers to a brown liquid made by harvesting immature persimmons in the summer, crushing them to extract juice, and then fermenting this juice for over a year. This liquid contains a large amount of tannins and organic acids (such as acetic acid and butyric acid), which give off a strong unpleasant odor. Generally, the longer it is stored, the better it is considered. However, if poorly managed, it can gel and become unusable.

Composition and Properties of Persimmon Tannin

Normally, this is used as is, but in recent years, it has become common to refine it by removing impurities such as organic acids, which also eliminates the unpleasant odor. Although the odor diminishes within a few weeks after processing, the essential component of kaki-shibu is still tannins, so refining does not affect its dyeing properties.

Tannins are also commonly associated with tea, where they mainly refer to catechins. Additionally, the term "polyphenols" has become widely used in recent years, and tannins are a type of polyphenol. In other words, the term polyphenols encompasses a broad range of substances, within which tannins exist, and catechins are a specific type of tannin.

There are many types of tannins, but historically, they can be broadly categorized as substances used for tanning hides. Incidentally, the tannins in kaki-shibu are said to be of the condensed type.

Currently, chrome tanning has become the mainstream method for processing cowhide, but leather tanned with tannins is still highly valued. The rich amber color that deepens over time is a result of tannin tanning. However, the tannins used here are of the hydrolyzable type, which differ from those in kaki-shibu.

Uses of persimmon tannin

Kaki-shibu has been used in Japan for a long time, primarily for its various beneficial properties. For example, its water-repellent nature made it suitable for use in traditional umbrellas and fishing nets, while its durability allowed for its application in willow baskets, fans, and Japanese paper products, as well as for coating building materials or being consumed as a medicine for high blood pressure or applied to treat burns and frostbite.

In clothing, it was used as "kaki clothing" during the Heian period. Recently, kaki-shibu has garnered attention as a multifunctional paint that does not cause problems related to chemical substances known as sick house syndrome, such as atopic dermatitis.

Its property of absorbing formaldehyde has led to its use in interior applications, and it is increasingly being applied to exteriors and foundational parts as well. Research is even being conducted on the metal plating capabilities of kaki-shibu, recognizing its gentle qualities.

Recently, kaki-shibu has also been utilized as a main ingredient in soaps that prevent aging odors. Additionally, it is an indispensable component in the creation of "Ise-gami," used in kata-yuzens (a traditional dyeing technique).

Popular sake bags are also made by repeatedly applying kaki-shibu to enhance the strength of the cloth used to press sake. It is indeed a remarkable substance with various benefits, including preservative effects, antibacterial properties, and insect repellent qualities.

Currently, its most significant use is as a clarifying agent for sake, but there has been a rapid increase in its use for dyeing in recent years. In fact, our kaki-shibu dyeing process plays a part in this trend.

Kakishibu Dyeing” is like wine

Since kaki-shibu is a natural product, quality control like that of chemical products is difficult. The quality can subtly vary depending on the year’s harvest, management methods, dyeing seasons, and weather conditions. It is reminiscent of wine in that regard. Based on our experience, the best dyeing occurs around the rainy season.

When fabric dyed with kaki-shibu is exposed to sunlight, it can change to a darker color within a short time during summer. This is likely how the term "sun-dyed" originated. Conversely, if stored in a dark room away from light, it can astonish with the beautiful dark colors it develops over time.

Applying heat can also deepen the color, and exposure to wet rust can cause it to turn black. Even strong acids like lemon juice can alter the color. Indeed, kaki-shibu dyeing is like a living process.

Commitment to “Kiki

Our products made of "naturally colored canvas" primarily utilize kaki-shibu dyed fabric. Unlike typical dyeing processes, we use only natural persimmons for dyeing, which imparts a warmth and familiarity to the material that resonates with us Japanese. However, it is unfortunate that many products on the market use chemical pigments, leading to misunderstandings about the original color and texture of kaki-shibu.

We have traditionally dyed using only pure kaki-shibu without any additives, but to pursue even higher quality, we have begun using kaki-shibu made from the finest "Tenno persimmons" as raw material.

Kaki-shibu is originally produced from persimmons with a high tannin content, such as "Tsurunoko" and "Horenbo," but the persimmons used exclusively for making kaki-shibu have the highest tannin content of all, which is "Tenno persimmons." Despite its quality, the usage of kaki-shibu has decreased compared to the past, leading to a significant reduction in its cultivation, making it very challenging to secure enough for dye production. Thus, manufacturers generally source varieties that are easier to obtain tannin-rich persimmons from various regions in Japan.

Therefore, we are working with the kaki-shibu specialty manufacturer, Iwamoto Kame Taro Shoten, located in Yamashiro, Kyoto, to ensure we can secure as much supply as possible. We take pride in realizing the highest quality kaki-shibu dyeing through this collaboration.

For hand-painted designs, we use precious kaki-shibu that has been aged for five to six years, known as "tamashibu." This offers deep colors and a luster reminiscent of lacquer that cannot be found in younger kaki-shibu.

Full text authored by / Yamamoto, Representative Director, Yamamune Dyeing Company, Limited

The greatest commitment of Creare Kiki is to use "natural-colored canvas" made from persimmon tannin and natural dyes. However, did you know that there are various materials when it comes to persimmon tannin and natural dyes?
We would like you to know the qualities and characteristics of each dye material.