Nine deaths serve as reminder of food safety issues

Nine members of a family in Heilongjiang province died last month after they ate homemade suantangzi, a type of thick noodles made from fermented corn flour.

In a case that made headlines, the National Health Commission said the fatalities, which occurred in Jidong county, were caused by bongkrek acid, a respiratory toxin produced by a bacterium that contaminated the noodles.

In summer and autumn, fermented food made of rice or flour is susceptible to contamination from the bacteria, which can survive even when the food is boiled at a high temperature.

There is no specific antidote and the fatality rate from such infections can exceed 50 percent.

The commission warned the public against making or eating such foods, which include fermented glutinous rice dumplings and fermented rice noodles.

It said 14 bongkrek acid poisoning cases had been reported in China since 2010, resulting in 37 deaths and involving 84 people.

Flour and rice are not the only staples fermented in the nation's households. From vegetables to meat, Chinese have shown their creativity in making a variety of fermented and pickled foods, a tradition that is more than 2,000 years old.

In addition to preserving many different foods for long periods of time, pickling can bring out unique flavors.

Whether served as a side dish accompanying porridge or noodle soup, or used as a condiment for stewed fish or boiled meat, pickled food is an essential part of the Chinese daily diet.

In different areas, people use contrasting ingredients and methods to make this food. Common ingredients include cabbages, cucumbers, radishes, ginger and garlic, as well as proteins.

In northern areas of China, pickled food is usually marinated with a high salt content, while in the south, it is traditionally fermented with a low salt content and lactic acid bacteria.

In the northeast, after napa cabbage is harvested in late autumn, families begin to make pickled cabbage.

The cabbage is dried in the sun for two days. It is then cleaned, the outer leaves are removed and the base is cut off.

Jars used to ferment the cabbage should be thoroughly clean and dry.

Salt is placed in the bottom of the jars before a layer of cabbage is added. Alternate layers of salt and cabbage follow until the jars are full.

A heavy stone is then placed on the cabbage layer at the top. After several hours, water is added until the jars are full again.

The pickled cabbage is usually ready to eat after a month. The amount of cabbage and salt used is key to this dish, while each family has its own recipe.

Cabbage preference

In September and October in Hangzhou, capital of Zhejiang province, pickled cabbage is made by families using methods similar to those in the northeast.

However, in Hangzhou, older cabbages are preferred and these are usually covered by bamboo shavings, before a stone is placed on top of the bamboo.

According to Liu Xin, 48, a chef from Yunnan who owns two restaurants in Beijing specializing in the province's cuisine, pickled food is used each day in Yunnan and different areas have pickles with contrasting flavors, from vegetables and fungus, to beans and fruit.

Pickled rose Chinese mustard, which has a complex aroma of soy sauce, sugar and roses, is a signature Yunnan pickle.

After winter sets in, fresh Chinese mustard is cleaned and cut, marinated in brine three times before being fermented with a special sauce made from sugar, rose sugar and fermented flour sauce.

Whether fried for use in dishes or added to snacks and staple foods, pickled rose Chinese mustard is a common ingredient in family kitchens in Yunnan.

"We only use the best-quality soy sauce to marinate the Chinese mustard," Liu said.

Pickled leek flower from Qujing city is another signature Yunnan pickle. The minced leek flower is marinated with kohlrabi－a type of cabbage with an edible stem－chili, red sugar, rice liquor and salt.

After fermenting for about six months, the acrid leek flower and the plain sliced kohlrabi turn into yellow and red pickle, which is tender and crunchy, sweet and salty.

"In Yunnan, two particular characteristics are the local herbs and spices used to marinate pickles," Liu said, adding that brown sugar and the local kaoliang spirit are "musts".

"In addition to bitter fruits, such as local pawpaw, others, including strawberries and pears, are made into pickles by locals," Liu said.

In Yunnan, fish and meat are also used to make some pickles.

For example, dried fish mixed with chili powder, Sichuan pepper and salt will turn into the delicious yuzha, or pickled fish, after being marinated for a month.

Liu said that when he was a child, each family in his neighborhood had its own signature pickles.

"My grandmother was good at making qiezizha, or eggplant pickle, and pickled chili, which can be fried with meat or steamed with fish," he said.

"If you discuss eggplant pickle with people from Yunnan, it will definitely make their mouths water."

Liu said most pickles in the province can be made at any time of year, and some ingredients, such as eggplant, start to be harvested in autumn.

"We have different ingredients to enjoy each season, such as flowers in spring, fungus in summer, fruits in autumn and vegetables in winter," Liu said.

"Unlike northern parts of the country, where pickled food is more about storage, in Yunnan, the pickle is used to bring more flavor to our cuisine, and its sour, spicy taste is a favorite."

Liu thinks that people in Yunnan are highly selective when they buy pickles from markets, and only choose the best-flavored ones.

"They won't shop for pickles at a store they are unfamiliar with, and pickle businesses only usually start to thrive after winning praise from locals," Liu said.

Two methods

In Sichuan province, pickled food is produced mainly by two methods. One is used to preserve it for longer, and the other, known as "bath-pickling", entails making it overnight.

Tang Aofei, 30, a chef from Leshan, Sichuan, who specializes in the province's cuisine, said that when he was a boy, he was always caught stealing pickles in the family kitchen.

"My favorite pickle is cowpeas," Tang said. "When I came home from school and dinner was not ready, I would pick some cowpeas to eat as a snack."

An earthenware jar stands in Tang's home, to which his mother keeps adding cowpeas and radishes. They are usually marinated for a week. Another earthenware jar is used to marinate ingredients such as ginger for a longer period to cook with fish or meat.

In the family kitchen, there are also glass jars to marinate the "bath pickle". "Bath pickle can be ready overnight, is crunchy and fresh, but not too salty or sour," Tang said.

He learned to make Sichuan pickles from his aunt. "The key is looking after the brine. It's like taking care of a potted plant that you have to watch every day. You also have to choose the right spot in which to place the jar," he said.

"If the brine becomes too sour, or there are too many flower-like bacteria in it, you need to restart," he said.

Tang added that if it is well looked after, brine can keep for more than 20 years.

He said that when his aunt and her husband went on long-distance trips, they always traveled with a jar of their pickle.

Popular choice

In Zhejiang, Anhui and Guangdong provinces, meigancai, a dry pickled Chinese mustard, is one of the most popular foods.

The green Chinese cabbage used to make the mustard is harvested and trimmed before Qingming Festival, before being placed in sun to dry.

It is salted or placed in brine, kneaded and left to ferment in large clay urns for 15 to 20 days. The cabbage is then repeatedly steamed and dried until it turns reddish brown and becomes highly fragrant. It is usually cooked with stews.

In Chongqing, the most popular pickled food is zhacai from Fuling district－a type of pickled green-stem Chinese mustard, which is salted, pressed and dried before being rubbed with chili paste. It is then fermented in an earthenware jar.

It is both crunchy and tender, and the taste is a combination of spicy, sour and salty.

In 2008, the craft of making Fuling zhacai, a popular product considered a good accompaniment for instant noodles, was inscribed as a national intangible cultural heritage.

Fuling Zhacai has become a popular local brand valued at more than 34 billion yuan ($5.07 billion). The company's income last year was nearly 2 billion yuan.

Even though pickles are mostly homemade, some time-honored brands largely use modern facilities to manufacture them. They usually start by mastering the skills required to make handmade pickles, before producing these uniquely-flavored products on a mass scale.

Sanhesimei, founded in 1817, is a well-known traditional pickle brand from Yangzhou, Jiangsu province. Its pickles, made from ingredients such as cucumbers, Chinese artichokes and lettuce, are refreshing, sweet, crisp and tender, and retain the original taste of the ingredients without any additives being used.

In Beijing, Liubiju, which has made pickles for nearly 500 years, is the oldest and best-known manufacturer of its kind in the Chinese capital.

Its products include sweet radish, sweet cucumber and sugar garlic pickles. Ingredients for Liubiju pickles are carefully chosen and a strict working practice is followed. For example, the soybeans chosen come from Majuqiao, Fengrun county, Hebei province, and Tongzhou district in Beijing, as they are particularly plump and oily.

To make sugar garlic pickles, garlic from Shandong province is harvested before the summer solstice. The manufacturing process involves eight steps, including peeling, marinating and placing the rolled garlic in jars. The pickle is generally ready to use by Mid-Autumn Festival.

The craft of making Liubiju pickle was inscribed as a national intangible cultural heritage in 2008.

Yang Yinxi, 63, who comes from Shanxi province, and has been making soybean sauce and pickles for more than 40 years, cuts a 50-kilogram kohlrabi each day into slices less than 2 millimeters thick.

In an interview with Beijing media outlet Qianlong, he said, "Compared with pickles made by using modern methods, the fermented soybean paste used for traditional handmade pickles ensures a rich flavor that modern skills cannot match."

Local artichokes are key ingredients for Chinese pickles, with those grown in Helan county, Ningxia Hui autonomous region, among the most-prized in the country.

Tan Yong, deputy general manager of Houshengji, a local snack and pickle brand, said 70 percent of Chinese artichokes are grown in the county.

The artichokes are seeded in March and harvested in late September or October. This year, Houshengji used more than 7,000 metric tons of them to make pickles.

"The hardest job is digging them out of the soil. Unlike peanuts, which can be dug out with force, it is easy to break the skin of an artichoke. Once broken, it will soon go bad," Tan said.

After being harvested, the artichokes are washed, and those selected are marinated in large pools, where seasoning is added.

Contamination risk

Ruan Guangfeng, a food safety expert from the China Food Information Center, considers pickled food produced by factories, where there are strict rules for sanitary conditions and the fermentation period, to be safer than that made at home.

"All homemade fermented food has the risk of bacterial contamination, so I don't recommend making it," Ruan said.

"If you do want to make pickled food at home, you first need to learn about food safety, such as the need to often change the water when marinating grains, and that storage areas should be well ventilated and damp-proof," he said.

Making such food at home comes with safety risks. Nitrite, a salt of nitrous acid, is a major concern in pickled food, while bacteria and methanol can form in homemade wine. In smoked fish or preserved meat, excessive levels of the organic compound benzopyrene can cause cancer.

Ruan said studies have shown that as fermenting progresses, nitrite content is gradually reduced until it is almost undetectable.

"If the food is fermented long enough, there should be no worries about nitrite content. So, avoid eating food that has just been pickled, and instead wait for at least two weeks," Ruan said.

He added that whether or not there is nitrite in pickled food, there is still a high salt content, so people should not eat too much of it.

"Pickled food can also be used to replace salt in cooking, as it not only brings out unique flavor, but also adds minerals and dietary fibers to a dish," he said.