Kagoshima seems to be made for making Kurozu. It is located along the south-western tip of the island of Kyushu, facing the active volcano of Mount Sakurajima. Its bay location, balmy climate, and presence of the volcano make it the ideal place to produce kurozu the traditional way. Yes, Kagoshima is well-known for its ?Black Label Products? such as kurozu, wagyu beef, chicken sashimi, and Berkshire pork dishes. It?s also responsible for selling high-quality tankans, but the standout is definitely their kurozu, which has a history of more than 200 years.?

There are few places in Japan that possess the natural ability, or some might say, knack, that the prefecture of Kagoshima has for making kurozu. Due to its rich geographical workings, which leaves it with a slightly more temperate climate than other parts of Japan, along with the prefecture?s abundant supply of underground spring water, Kagoshima is no wonder the perfect place for making quality kurozu. In fact, Kagoshima is the largest exporter of kurozu in Japan precisely because of its environmentally advantageous edge, which allows koji-kin (the bacteria needed for fermentation) to thrive in the air.

Fukuyama town, which is about a 40-minute drive from Kagoshima Airport, is one of such towns that has been guarding over 200 years of artisan-kurozu making ways. Kurozu isn?t just a product for them, it?s a lifestyle they believe and immerse themselves in. Their dishes, beverages, sweets, salad dressing, and capsules, all rely heavily on kurozu. Even their farmed yellowtail fish consume kurozu-based feed.

Producing vinegar in factories is actually the norm. Factories that house the production facilities may seem more efficient and involve less manual work, but the resulting taste differs a great deal from kurozu that is made with the traditional method. But just what is the traditional method?

This traditional method was passed down from the Edo Period (1603-1868) and practised labouriously today in Fukuyama. They?ve converted the large spaces and fields of the town into tsubobatake (?Field of Vinegar Jars?) rows, containing their beloved kurozu. Overlooking these fields is the stunning Sakurajima, which is located on a former Kagoshima island about 3.5 kilometers away from the Kagoshima Port. It is one of Japan?s most active volcanoes, amounting to two or more minor eruptions within a day. It is believed that the ashes spewed from the volcano help strengthen the ecosystem of Kagoshima when it comes to growing their signature tankans on fertile land, or farming, and possibly even nourishing the underground spring water, too, which is important for the production of kurozu.

The traditional method of making kurozu involves mixing in three essential ingredients into black earthenware jars (Aman Jars), which is then topped off with a sprinkle of koji-kin mold on the surface of the mixture – a type of good bacteria to help in the fermentation process. The three ingredients that are needed for good quality kurozu are: steamed, unpolished rice, fresh supply of water, and the sunlight and heat of the sun. Fukuyama town has a strong, steady stream of underground water that is absolutely essential for the kurozu making process. This, paired with Kagoshima prefecture?s unusually long hours of sunlight, help move along the fermentation process steadily faster.

Why the use of bacteria? Koji-kin, a good bacteria, is dubbed the country?s national fungus in 2016, for possessing beneficial qualities to digestion and gastronomy. Koji-kin is a key player in the acetic acid fermentation process, which breaks down the mixture to eventually form kurozu. When the bits of koji-kin sink to the bottom of the 60cm-tall jars after a period of time, you would know that the process of fermentation is completed. Every so often (about every two weeks) in the three years of fermentation, the jars need to be opened and stirred with bamboo poles to oxygenate the mixture as the bacteria require oxygen to ?work its magic?.

This entire process, from adding the three ingredients into the jars, to stirring, is done by hand by workers who must adhere to strict regulations, especially when handling the pre-kurozu mixture. It is a traditional method that is by no means straightforward, easy, or fast. Patience, caution, and care are what marks the kurozu-making process in Fukuyama town, and many other kurozu farms scattered across the prefecture. After a period of fermentation for about three years or more, this ?black gold? is now ready to be packaged, sealed, and then sold to the markets.

Kagoshima hosts plenty of kurozu farms and factories, and Fukuyama town is just one of many. Kakuida is a kurozu farm and factory that conducts tours and produces kurozu that is famously sold around Japan and exported to other parts of the world.

Indeed, Kagoshima is not only a beautiful prefecture but a practical one, especially when it comes to making kurozu.