The power of production methods

The pot room is where the traditional Kamadaki (pot boiling method) produces soap. The process takes around 100 hours from start to finish: saponification, salting out, still standing, and final salting out.

The oils and fats that serve as raw materials are placed in the pot, heated, stirred and combined with a caustic soda solution. This triggers the hydrolysis of the oils and fats in which the fatty acid and glycerin separate; the fatty acid reacts with the caustic soda to become soap. This is known as "saponification." Salt is later added to this mix so that the soap molecules collect at the top of the pot while impurities sink to the bottom, a process known as "salting out." After salting out, the pot is maintained at heat to wait for the soap's purity to increase (still standing). Twenty four hours later, there is another round of salting out that creates the finished "soap body."

Matsuyama's soap body has 98% purity. Of the remaining 2%, some 1.2-1.7% is glycerin. Glycerin, which is the oldest known moisturizer and helps to relieve tightness, naturally dissolves into the soap body. Boiling the oils and fats in a pot produces soap with the cleansing power best suited to human skin. This is one of the main features of Kamadaki soap. It is also why we have continued to practice this traditional production method for more than 70 years.

Soap is allowed to cool and solidify overnight before being cut up. Matsuyama's soap production technique is called the "frame kneading method."

The soap starts as a large rectangular solid, and is cut into blocks of equal thickness using stainless steel wire. This stage is called "block cutting." Two workers man the stainless steel wire, one holding each end, and working and coordinating their movements so that they pull it tight with the same speed. Success is defined as the soap being cut on an absolutely straight line with no curving whatsoever. At the next step, the soap is carefully transported to and placed in a "small cutter" so that it is not damaged in the process. It goes through a small cutter twice, once in the vertical direction and once in the horizontal. At this point, it is at an easy-to-use size that fits in the palm of your hand. From there, the soap moves to the drying and maturation process.

This entire process of using frames, cutting by hand, and then drying and maturing the soap is called the "frame kneading method." It is the same process used to produce the olive oil-based soap traditional in Mediterranean countries. It used to be very common in Japan as well, but today is not widely practiced due to the labor and time required.

In summer, the pot room can become chokingly hot with the steam that rises from the pot. But even in this heat, the craftsmen do not let up, continuing to fire the pot and produce the soap. "There may be written production instructions, but there are many things that cannot be included in a manual." The craftsmen confirm this.

"During saponification, a chemical reaction takes place in the pot that gives off reaction heat. This is a natural phenomenon and difficult to predict with any accuracy. You have to be aware of the heat being applied to the pot, the reaction heat being produced, and the ambient temperature, or the soap will overheat." "We pay attention to the surface of the soap. That's how you judge how far the reaction has proceeded inside. If the surface reaches a rolling boil, it's too hot and you need to immediately inject saltwater before the pot gets out of control."

These kinds of instantaneous judgments cannot be written out in the manual. Our goal is to produce better soap, and to do that we allow our workers to make full use of their experience and instincts, and to make the quick decisions that are sometimes called for.

Kamadaki soap body in chip form is transported from the Sumida Factory to the Fujikawaguchiko Factory. There, essential oils, plant extracts and moisturizing ingredients are added and thoroughly mixed in. The mixture is kneaded over and over again until it is smooth. It is then formed in molds and branded with a carved seal. This is the "milled soap process."

The condition of the soap depends on the materials mixed in, and also the temperature and humidity. It may change so much that it impacts how the machinery itself operates. If it is too hard, the brand becomes thin and illegible; if too soft, the soap fails to separate properly from the mold. Operators must adjust the speed and temperature settings of the machinery to the subtle balance of hardness and softness in the soap, adding and removing water content as required. This is something that only humans can do, people who have observed the process many times before and understood it with their own hands. They are required to make extremely fine adjustments within very limited windows of time, searching for the optimum conditions. One of the features of milling is that it produces large quantities of soap in a very small number of days. That does not, however, mean that we want to leave everything up to machines and churn out large, unmanageable volumes. That is our approach to and philosophy of manufacturing.

We mentioned glycerin just briefly in the description of the pot boiling method (Kamadaki). It is one of the most important materials in cosmetics. Glycerin can be used for many different purposes: bringing moisture and softness to the skin, making liquids thicker and more viscous, dissolving other materials, and improving the foaming of cleaning agents.

It has another extremely important role. It is glycerin that makes soap transparent. X-ray analysis finds that soap consists of fine, fiber-shaped crystals. Glycerin influences the ability of the molecules that form the crystals to attract each other. When it is present, it suppresses the growth of the crystals, causing them to become even finer and the soap to become transparent rather than reflecting visible light. This is the science that is behind transparent soap.

As an experiment, try putting Matsuyama transparent soap on a newspaper. You should be able to see the words underneath. In fact, at Matsuyama being able to clearly read print through the soap is one of our standards for transparency.

"In a large space, no humans present, a giant machine works day in and day out mass-producing the same objects." That is probably the most common image of a factory. At Matsuyama, it is different. Here in the Skincare Filling Room, for example, the machines are small and they are run by people. Small machines are best at producing small quantities. Some may consider this inefficient.

We do not. We think it is the optimum scale for our style of manufacturing. Matsuyama's strength is in high-mix, low-volume production. To be honest, it is very painstaking and labor-intensive. For instance, if you need to fill Product B after you fill Product A, you first have to disassemble the machine and wash all of the parts. Then you have to reassemble it. It's a lot of work, but it's one of the things you can do when you have your own factory. The wide variety of our products enables us to offer customers that many more options. High-mix, low-volume production allows us to achieve the things that we are most passionate about.