Traditional Japanese culture is rooted not only in the glamorous aspects of festivals and performing arts, but also in the tools and techniques deeply connected with daily life. One representative example is the “natural whetstone. The tools used to sharpen swords and knives are not mere chunks of stone, but are cultural assets that encompass a long history, craftsman’s sensitivity, and aesthetic sense.
In recent years, however, natural grinding stones have faced a crisis of survival. This is due to the depletion of natural resources, the rise of man-made grinding wheels, and modern society’s value system that places a premium on “efficiency. In this article, we focus on the material and culture of natural whetstones and explore their significance and potential for survival in the modern age.
Table Of Contents
- Natural Grinding Stones as a Resource: A Dwindling Tradition
- Evolution and cultural selection of man-made grinding wheels
- What are the traditions that should be preserved?
- Why use a natural whetstone when you can sharpen with a man-made whetstone?
- Does a knife that can cut change the taste?
- Overseas Evaluation and Price Trends of Natural Grinding Wheels
- Preservation or Utilization: Cultural Properties and Support as an Institution
- Conclusion – should we keep it, even if it costs taxpayers money?
Natural Grinding Stones as a Resource: A Dwindling Tradition
Natural whetstone is a type of slate or siliceous rock formed over a long geological period. Most of the mined areas in Kyoto, such as Nakayama, Daitori, and Okudono, have already been closed, and most of the natural whetstones on the market today are either stock that was dug up and stored in the past, or released from private warehouses.
In particular, the Nakayama Mine, located in the Narutaki area of Kyoto, reached its peak from the Meiji period to the mid-Showa period. Mining was mainly done by hand, and in a working environment where the miners were stuck to the slopes of the mountain, they spent all day long chasing the strata with pickaxes and chisels. Due to problems with land rights and mining rights, the mine has been closed since the bubble period, and today, only a small inventory of mined whetstones is available on the market.
The Agency for Cultural Affairs’ “Basic Data on the Promotion of Traditional Craft Industries (2020 Edition)” also points out that the problem of resource depletion in traditional mining-based industries is serious and that remining is physically and economically difficult (*1).
Evolution and cultural selection of man-made grinding wheels
The role of natural whetstones has already been replaced in most areas by artificial whetstones. Especially for rough and medium sharpening of kitchen knives, the high performance and homogeneity of ceramic and diamond whetstones have come in handy, and artificial whetstones have become the mainstream in terms of price and availability for home use.
This is similar to the example of chemical fertilizers: in the early 1900s, when German chemist Fritz Haber established a technique for fixing nitrogen in the air (the Haber-Bosch process), agriculture, which had previously relied on organic fertilizers, quickly shifted to chemical fertilizer-based farming. This is a typical example of how technological innovation has rewritten cultures and customs.
The same is true of the media transition from vinyl records to CDs and from CDs to streaming. In a sense, it is a “natural flow” that technology, with its superior convenience and reproducibility, will weed out the old culture.
What are the traditions that should be preserved?
So, are natural grinding stones a “tradition to be preserved”?
The haiku poet Matsuo Basho advocated a thought-provoking concept known as “fūyō fūryū. Basho believed that both are important. Basho taught that both should be compatible.
If we look at natural whetstones from this perspective, their function as a tool (to sharpen knives) can be replaced by artificial whetstones, and this may be an area that can change with “fads”. However, the “minute differences” that craftsmen and chefs feel through their tools, such as the taste of sharpening, the sound of sharpening, and the slight differences in the edge of the blade, are truly an expression of a sense of beauty that is “eternal.
Why use a natural whetstone when you can sharpen with a man-made whetstone?
Because it’s romantic. And it can’t end there…
In fact, if you just want to attach a knife blade, a synthetic whetstone is sufficient. Especially in the process from rough to medium whetting, artificial whetstone is even more efficient. However, in the area of “finishing whetstone,” there are still many cases where natural whetstones are superior.
One of the reasons for this is the “individuality of whetstones. The grain size and hardness of natural whetstones vary slightly depending on their place of origin, geological formation, and mining location, and this produces a variety of sharpening and blade surface finishes. This is an expression that is difficult to obtain with the uniformity of artificial whetstones.
Research has also shown that knives finished with natural whetstones are not only sharp, but can also cut through food without destroying its cells, making a difference in the appearance luster and taste of sashimi, for example (*2).
Does a knife that can cut change the taste?
From a scientific perspective, sharpness also affects taste: in 2018, a research team from Ajinomoto conducted a taste analysis using a food taste sensor on tomatoes and fish cut with knives of different sharpness, and confirmed that there were slight differences in “umami” and “acidity” (*3).
This is believed to be due to the fact that the amount of flavor components leaked out varies due to the different degree of cell destruction caused by cutting. In other words, a high-precision blade finished with a natural whetstone can affect not only the “appearance” of a dish, but also its “taste.
Overseas Evaluation and Price Trends of Natural Grinding Wheels
In recent years, the reputation of Japanese natural whetstones has been growing overseas, and their popularity has skyrocketed, especially among professional chefs and knife collectors in Europe, the United States, and China. It is not uncommon for finishing whetstones produced in Nakayama and Daitoshi, Kyoto, to fetch prices in excess of several hundred thousand yen on eBay and specialized auctions.
In some cases, whetstones labeled “Nakayama Hakusuita” or “Okudono Saita” are even treated as “artisanal investment objects” in the same way as vintage Japanese swords. In addition to the rarity of the whetstone itself, one factor behind this is the growing international interest in Japan’s unique cutlery culture.
Preservation or Utilization: Cultural Properties and Support as an Institution
The insistence that natural whetstones should be preserved as cultural assets has gradually led to institutional movement in recent years. For example, the Agency for Cultural Affairs is considering including not only “intangible cultural properties” but also the supporting “tools and materials” and “production techniques” themselves as targets of support.
In 2021, a grinding stone manufacturer in Kyoto was selected by the Agency for Cultural Affairs for its “Local Cultural Resource Utilization Project,” and digital archiving through documentation of the former mining site and interviews with craftspeople is underway. Furthermore, there exist cases where local governments have conducted conservation activities for grinding stone mountains through crowdfunding.
Thus, we are entering an era in which the future of traditional technology depends on flexible institutional design that takes into account not only “preservation” but also “utilization.
Conclusion – should we keep it, even if it costs taxpayers money?
So, should these natural grindstones be “protected by taxpayers?” Let’s return to the question, “Should taxpayers protect these natural grinding stones?
Personally, I am skeptical of using taxpayer money to preserve natural grindstones. This is partly due to my own familiarity with libertarian ideals of small government. Not only natural whetstones, but the mechanisms for determining “what cultural properties are important to the nation” are often subject to political influence, and as a result, tend to become hotbeds of interest and vested interests.
We have seen many cases where cultural preservation activities, which started out with good intentions, eventually became the purpose of maintaining the organization responsible for them, and fell into bureaucratic self-purposes.
That is why we believe that the accumulation of voluntary support and wisdom, even on a small scale and with substance, by people who see the value in natural grinding stones will lead to essential conservation.
Source/Reference:
- *1: Agency for Cultural Affairs, “Basic Data on the Promotion of Traditional Craft Industries (2020 edition).
- *2: “The Relationship between Knife and Taste in Japanese Cooking” (Bulletin of the Japanese Food Culture Society No. 8, 2021)
- *3: Ajinomoto Corporation, Research and Development Center, “The Effect of Blade Sharpness on Food Taste Evaluation” (2018, internal report abstract).