In Taiwan’s isolated Dongyin Township, 100 nautical miles northwest of Keelung City, a family has been brewing natural vinegar according to traditional methods since the 1950s. The health effects of such vinegar are supported by the pharmaceutical classic “Compendium of Materia Medica” by Li Shizhen, first published near the end of the 16th century, which states that vinegar eases pain, eliminates swelling and kills bacteria.
Much more recently, pharmacy professor Sadao Nakayama of Tokyo-based Showa University showed in 1993 that the acidic liquid can help purify blood, strengthen the stomach and intestines, and prevent calcium loss.
After the 1955 Battle of Dachen Archipelago, off mainland China’s Zhejiang province, many ROC soldiers retreated to Dongyin, where they outnumbered the sparse local population. The township, comprised of Dongyin and Xiyin islands, covers just 4.71 square kilometers. Due to its remote location, rocky hills and steep granite sea cliffs, resources were scarce and life was hard.
Moreover, as part of the frontline between Taiwan and mainland China, Dongyin was under strict military control until 1991, with tight limits placed on the distribution of goods and travel to and from the islands.
“One of the newly arrived soldiers was a master vinegar maker who passed the techniques on to his comrade Chen Rui-ji, who established Chu Kuang Rice Vinegar in 1967 to support his family,” said Zhou Jie-yu, daughter-in-law of the now 77-year-old Chen and current manager of the business.
According to Zhou, the family’s products are made solely from rice and water, employing only traditional methods and equipment. No acetic acid bacteria or vinegar concentrate is added, and without mechanization, maximum annual output is 6,000 bottles.
“First we steam rice and put it in crocks, where as it sits the starch is converted to sugars, and then the sugars into alcohol. This first phase of fermentation can take up to two months, and during this time natural acetic acid bacteria find their way into the crocks. Then, as the fermenting product requires oxygen to make vinegar, water is added.
“Afterward, we wait two to three months until the rice is completely integrated with the water like rice milk, in which you cannot see grains of rice. Gradually, the mixture will turn amber and we begin to press and filter it. The last step is to sterilize the vinegar by heating it. Once it’s cooled, we bottle and package it for sale.”
Zhou noted that throughout the fermentation process, the temperature must be kept under 30 degrees Celsius for the bacteria to breed better. Water is also another important factor to ensure the quality of the vinegar. “Only mountain spring water will do. It must be very clean or it will spoil the vinegar.”
Dongyin is an ideal site for producing vinegar, she pointed out, as the local volcanic rock, porphyritic andesite, contains the mineral zeolite, which filters and purifies water. In addition, it lies in a subtropical monsoon climate zone at 26 degrees 22 minutes 36 seconds north latitude.
“It experiences very distinct seasons, with winter temperatures sometimes falling below zero C,” she said. “Humidity and temperature play important roles in fermentation. If it’s too hot and humid, mold will easily breed, resulting in bad bacteria and affecting the quality of the vinegar.”
When the family tried to make its vinegar on Taiwan proper it failed. “We realized that whenever we used tap water, our vinegar would go bad,” Zhou said. “Whether it’s water from a desalination plant or running water, chemicals containing sulfate or sodium chloride are added for precipitation. The chemicals prevent acetic acid bacteria from breeding properly and the vinegar deteriorates.”
According to Zhou, one way to distinguish high quality vinegar is by smell. “If it’s processed or synthetic vinegar, there will be a pungent odor; if it’s brewed, it’ll smell like rice.”
Another method is to drink it. Low-quality vinegars will make one’s throat sting because of the glacial acetic acid that is added, whereas the sour taste of naturally brewed vinegars is not harsh but smooth, she said. “If you have an unopened bottle and can’t take a whiff or a taste,” the simplest way is to shake the bottle, she added.
“Generally speaking, bubbles don’t easily form in synthetic vinegars. Even if bubbles do form after shaking, they are large and disappear at once; however, for brewed vinegars, bubbles will form at the slightest shake of the bottle and will last quite a long time. In synthetic fruit vinegars containing fructose, there may be a lot of bubbles after shaking, but they won’t be as dense as those in brewed vinegar.”
In addition, naturally brewed vinegars will have sediment from the starch in rice, as in the case of Dongyin products, whereas synthetic vinegar is made from chemicals that dissolve in water, she pointed out.
Zhou said her father-in-law’s doggedness in following traditional methods is one of the main reasons the family business is not only still running, but one of Taiwan’s leading vinegar manufacturers. “The only thing we’ve changed is to set up a website,” she said. “Not even the price has been adjusted over the past decades.
“Many companies have wanted to cooperate with us or to purchase our production techniques at a high price,” Zhou noted. “However, my father-in-law is a traditional man. He has made it clear that if one day his descendants lose interest in manufacturing the vinegar, he would rather let our methods be lost than sell them to someone else.
“For now, as long as he is alive and healthy, we’ll continue brewing our vinegar, offering our customers a taste of persistence.” (THN)
Write to Grace Kuo at mlkuo@mofa.gov.tw