Gosorisul is the traditional distilled beverage of Jeju, a large volcanic island off the southern coast of South Korea. The name of this spirit is a combination of the words gosori, used in the Jeju language to refer to the typical Korean distillation apparatus; and sul, the Korean word for “alcohol,” often used as a suffix. The term for distilled liquor is soju. Soju originated in the 13th century when the Yuan Mongols brought the art of distillation to Korea from the Middle East. Some of the first distilleries were set up in the cities of Kaesong (in the far southern part of what is now North Korea) and Andong (in the eastern part of South Korea). Along with Kaesong and Andong, Jeju is known as one of Korea’s traditional centers of spirit production. Making gosorisul was traditionally considered woman’s work and was done in the household.
On the Korean mainland, soju is usually made from rice, but because of its permeable soils (composed mainly of black volcanic rock) and comparative lack of fresh water, Jeju is not suitable for wet rice cultivation. Instead, the island’s traditional staples are barley, various millets (including foxtail millet), wheat, sorghum, buckwheat, and some upland rice. Gosorisul is typically based on barley, millet, and sorghum. The first step in producing gosorisul is to make the fermentation starter, which is called nuruk: Wheat or barley is ground with a traditional millstone (maesdol) and the meal thus obtained is mixed with just enough lukewarm water to hold it together, and then kneaded until there are no clumps. This dough is then formed into discs or bricks, using the hands or feet to press it into a mold (the rim of a sieve will suffice). The nuruk cakes are covered with clean linen cloth or straw, stacked layer upon layer, and kept in a warm place so that they will start to ferment. During the fermentation process, various molds, yeasts, and bacteria colonize the nuruk. After about 20 days of fermentation, the nuruk is dried in the sun. Due to the need for warm fermentation temperatures and dry, sunny days, nuruk is usually made in summer and then stored in a hanging bag or a hangari (a traditional earthenware jar). Nuruk differs from the better-known Japanese koji in that wild microorganisms inoculate it naturally, and it contains yeast in addition to mold—in brewing sake, yeast and koji (Aspergillus oryzae mold) are added in different steps and come from different sources.
The brewing of the alcohol that will be distilled to make gosorisul can be done at any time of year apart from July and August, but usually takes place during the coolest months. It is best to make gosorisul with freshly harvested millet after Sanggang, the day that marks the first frost (this day falls around October 23rd, at the end of the ninth month of the Korean lunar calendar). Millet, or whatever grain is being used, is soaked in water for 8 hours and then milled, after which it is steamed in a traditional steaming vessel called a siru to make the sultteok or “wine cake.” In some cases, dry millet is ground and steamed. Both glutinous and non-glutinous millets may be used; the latter is often preferred, as it will not stick to the vessels used later in the process. Once the sultteok has cooled, water and ground nuruk are added little by little and mixed by hand until no clumps remain, and then the mixture is put in a large vessel called a suldok. Plenty of water is added and the suldok is sealed and left in the corner of the kitchen or another room for about 10 days, during which time the mash ferments. Sometimes, especially if brewing is done in the winter, the upper layer of the mixture in the suldok is set aside and enjoyed as cheongju (which refers to any clear wine made from grain), while the remaining contents are left until the following spring; the space left after the cheongju is removed is filled with additional nuruk and sultteok, for a stronger fermentation.
Now, finally, it is time to distill the contents of the suldok to obtain gosorisul. This is done with a special earthenware distilling pot known in the Jeju language as gosori, and in Standard Korean as sojugori. First, the contents of the suldok are transferred to a cauldron known as a sot, which sits over the fire. Next, the gosori is positioned atop the sot and any gaps between the two vessels are sealed so that no steam can escape. The upper part of the gosori is a bowl which is filled with cold water; as steam rises from the sot into the gosori and comes into contact with the cool underside of the bowl, it condenses into spirit and drips down a spout into a collection vessel. Gosorisul is a clear, colorless liquor with an alcohol content of up to 40% by volume. Due to this high alcohol content, it can last almost indefinitely if it is properly stored in a cool, dark place in a sealed container. Gosorisul tastes different from the rice-based soju of mainland Korea. On the palate, an initial burning sensation gives way to a smooth texture and rich, fruity notes. The flavor dissipates quickly, leaving the mouth clean and ready for another sip. Gosorisul made according to the artisanal process described above is prized for its high quality and drinkability, and is used during poje (a village festival) as well as jesa (a ceremony to honor ancestors) and other ceremonial occasions.
Today, the artisanal production of gosorisul is severely threatened. This is due in large part to the fact that, during the Japanese occupation of 1910-45, the production of traditional Korean spirits was banned, and this ban remained in effect even after 1945. Later, the Korean market was flooded with imported mass-produced Western-style liquors, and with the rice shortages of the 1960’s, home distilling and the use of grains for alcohol production were outlawed. Many of the traditional ceramic distilling pots were confiscated and destroyed, and the knowledge and techniques associated with small-scale distilling were not passed down to younger generations. Luckily, there has been renewed interest in traditional Korean spirits since the late 80s as people have come to recognize their value and high quality. Even so, there are mass-produced versions of gosorisul on the market, made with rice-based ipguk (koji) from Japan instead of local nuruk; and household production of gosorisul for personal or family consumption has virtually disappeared on Jeju. There is just one woman on the island who continues to make traditional gosorisul for sale. She works out of her home—a doljip, the traditional stone house of Jeju—and, fortunately, her son has taken an interest in distilling. It is estimated that the total annual production of artisanal gosorisul is less than 6,000 liters.