Tajiri Factory (Hanakatsuo Manufacturing Factory)
We receive katsuobushi from katsuobushi manufacturers from across Japan, such as katsuobushi processors from Yaizu, katsuobushi traders from Kyushu, and katsuobushi traders from Shikoku, as well as katsuobushi traders from overseas, such as those from Indonesia.
Regarding katsuobushi from Yaizu, there is a wide range of types ranging from freshly-made katsuobushi that is still warm to katsuobushi that has arrived after slowly crossing the Pacific on a boat. Although katsuobushi is stored in refrigerators during the summer, when outside temperatures are high, there are also instances where katsuobushi is stored in refrigerators during the winter, in order to prevent the ingredients from getting too cold, as the outside temperatures are too low. Katsuobushi with high fat content has fatty pieces on the inside of the ingredients, while katsuobushi with low fat content does not.
Also, because the skipjack tuna used for foreign-made katsuobushi swim close to the equator, they have little fat and have a good scent when shaved, while Japanese katsuobushi is smoked with domestic firewood, giving it an aroma that suits Japanese people.
Katsuobushi from Yaizu, which is a major producer of katsuobushi. 18-20kg in each case. They are neatly packed inside the boxes.Each pallet contains 35 cases and 700kg of katsuobushi.
Katsuobushi is made from skipjack tuna, which contain bones in their bodies.
During the process of making katsuobushi, there is a “bone removal process,” where the bones are removed from the fish in a water tank called the “hone-nuki (bone removal).” However, not all of the bones can be removed neatly at the katsuobushi manufacturing factories.
Although all of the bones used to be completely removed back in the old days, due to the transition toward mass production methods in recent times, there has been a gradual shift toward not removing all of the bones.
Certainly, there is katsuobushi for which all of the bones are removed, and not all katsuobushi contain bones. For foreign-made katsuobushi, especially for katsuobushi from Indonesia, the bones are removed relatively neatly.
During the “brushing process,” machines that remove dirt from carrots are used to remove the bones, skin, katsuobushi debris, and foreign matter stuck on the surface of the katsuobushi. The katsuobushi debris is collected and used as an ingredient for extracts, such as the “dashi pack.” Large foreign matter is discarded. In the past, “vinyl, plastic, and dust” were discovered on katsuobushi.
This is the process where metals on the surface and inside katsuobushi are detected and removed. In actuality, the metal detectors hardly ever react to katsuobushi, but it is said that a metal detector may react if the katsuobushi contains a lot of blood. The metal detectors serve their purpose during processing of “saba-bushi (katsuobushi made with mackerel instead of skipjack tuna).”
During the manufacturing process, the innards are removed from skipjack tuna for katsuobushi, but for saba-bushi, the innards are not removed. Therefore, the metal detectors react to the fishing hooks contained in the innards of the mackerel, which eat anything.
Metal detector sensitivity: Fe1.5 Sus3.0
Immersion (in Hot or Cold Water)
Katsuobushi is a very hard food. According to one document, it is the world’s hardest food. If a completed katsuobushi is shaved as is, the blade may not be able to withstand the hardness of the katsuobushi and get nicked.
Therefore, it is necessary to add moisture to the katsuobushi to soften it. Softening the katsuobushi not only makes it easier to shave, but also makes the shavings look better. Katsuobushi can be softened by immersing it in hot water ranging from 60 to 70 degrees Celsius for roughly 15 minutes. We say that the katsuobushi becomes “supple.”
Depending on the katsuobushi, some are immersed in 60 degree Celsius water for about 90 minutes, while on hot days in mid-summer, cold water is dropped from above for roughly 3 hours to allow the moisture to permeate. If the katsuobushi is immersed in hot water for too long, the “dashi” escapes. We base our decisions on our experience working with katsuobushi for many years.
Katsuobushi being immersed in hot water
Similarly to the immersion process, moisture is applied to the katsuobushi through steaming. Although the process varies depending on the type of katsuobushi and the quality of the fish, in general, moisture is applied for 20 minutes at roughly 120 degrees Celsius in an autoclave.
Even parts that do not receive moisture during the previous “immersion” process forcibly receive moisture in the autoclave, allowing moisture to enter the innermost parts of the katsuobushi. This process also provides sterilization.
However, this process is not applied to all types of katsuobushi. For example, moisture may not be applied in this manner to katsuobushi that our customer will use for “dashi,” as forcibly applying moisture to the katsuobushi will cause the “dashi” to escape.
The autoclave forcibly applying moisture to katsuobushi
We finally shave the katsuobushi. The katsuobushi shavings range in thickness from as thin as 10 microns to as thick as 1mm. 14 sharpened blades are placed on a rapidly rotating disc to shave the katsuobushi.
Thinly shaved katsuobushi melts on your tongue. This sensation of katsuobushi melting on your tongue can only be understood by somebody who has experienced it. Techniques for adjusting the blades for shaving katsuobushi cannot be learned overnight, and it takes roughly 3 years to learn how to adjust the blades to be able to produce shavings with the thickness you desire.
We dry the shaved katsuobushi. If it contains too much moisture, it becomes “moist, heavy” katsuobushi that does not look appealing. Also, moisture is removed from some types of katsuobushi products that do not go through “nitrogen inflation,” as mold tends to grow if there is too much moisture. It is possible for us to control the moisture based on our customer’s needs.
In addition, if the drying temperature is increased to remove moisture, the katsuobushi might get charred or pick up a “charred scent.” In order to retain the flavor while removing moisture, many years of experience are necessary. We remove moisture through hot air drying by firing a burner in the lower parts to create hot air.
We crush the shaved katsuobushi into small pieces. Shaved katsuobushi is used in various ways. Our company has customers in a wide range of industries, such as dashi makers, tsukudani manufacturers, convenience stores, sake brewers, and takoyaki restaurants. We must change the shape of our shaved katsuobushi according to the desired usage of our customers.
Therefore, we use this crusher to crush it into small pieces. We change the size of the shaved katsuobushi by adjusting the size of the screen that we place on the bottom of the crusher. Through these size adjustments, we are able to form good shapes for our customers’ product development. We are currently able to prepare shaved katsuobushi for over 200 types of products.
The crusher making shaved katsuobushi smaller
We remove heavy foreign matter. After katsuobushi is shaved, crumbs are left over. These crumbs can be called “seppa (cut wings).” They may be a portion of the surface skin of the katsuobushi or unintentionally thick shavings made by the shaving machine.
This process prevents these crumbs from entering the product along with thinly shaved katsuobushi.
Wind is entered into the machine from the bottom. Thinly shaved katsuobushi that is light rides the wind into the next process, while the heavy foreign matter cannot ride the wind and falls down. Pieces that are heavier than the product calls for are removed.
The shaved katsuobushi is passed through the metal detector one last time. The sensitivity is “Sus1.5” “Fe0.7.” This sensitivity reassures our customers who come to visit.
Although there are others who pass the product through the metal detector after it has been packaged, at our company, we pass the product through the metal detector as is. We check the sensitivity of the metal detectors before and after morning manufacturing and before and after afternoon manufacturing.
Removing metal debris that may be contained in shaved katsuobushi
We weigh the shaved katsuobushi based on the defined weight. As Kobayashi Foods specializes in “industrial katsuobushi,” we weigh shaved katsuobushi from 100g to a maximum of 10kg for each bag. Based on various factors, such as the quality of the ingredients and the status of the blades in the shaving machine, shaved katsuobushi has a different “bulk” when weighed, even if the same processes are used every day.
Because our staff members working at the weighing stations have accumulated experience over many years, they immediately recognize the dryness and quality of that day’s shaved katsuobushi.
Weighing the shaved katsuobushi
We remove the oxygen and replace it with nitrogen to prevent oxidization to keep the shaved katsuobushi from degrading.
Based on our customer’s desires, there are some products that do not go through nitrogen inflation. We have a large nitrogen inflation machine that can handle up to 5kg.
Performing nitrogen inflation on shaved katsuobushi
The shaved katsuobushi has been completed. After the raw skipjack tuna arrives to the port, between 1 month and over half a year is required until the shaved katsuobushi is completed. The efforts of the fishers, the katsuobushi makers, the katsuobushi shavers, and many others culminate in the completion. The products, which range widely from 100g to 10kg, are prepared for our customers in various industries.
Completion of the products made with the full effort of Kobayashi Foods staff members