What Is The White Dew?-Bailu

White Dew,” the 15th solar term in the Chinese calendar, marks the end of the Shen (申) month and the beginning of the You (酉) month. It falls around September 7th to 9th in the Gregorian calendar. “White Dew” signifies the increasing presence of coldness in the natural world. During this time, daytime temperatures remain warm with abundant sunlight, but evenings see a rapid drop in temperature, leading to a widening temperature difference between day and night.

As “White Dew” arrives, summer winds gradually give way to winter winds, and the cold air becomes more dominant. Additionally, the tilt of the Earth causes the sun to shift southward, resulting in shorter daylight hours and weaker sunlight intensity. This, in turn, leads to rapid cooling as the Earth’s surface loses heat through radiation.

The name “White Dew” originates from the idea that as the air cools, moisture in the atmosphere condenses into dew, often appearing white. In traditional Chinese culture, each season is associated with one of the five elements, and autumn is associated with the element of metal, which is symbolized by the color white.

According to the “Average Temperature Criterion” proposed by modern scholar Zhang Baokun, the period between 10-22°C in average temperature is considered either spring or autumn. Following this criterion, “White Dew” marks the beginning of autumn in various regions.

Proverbs related to “White Dew” caution people to dress appropriately for the changing temperatures. For example, “In White Dew, don’t go naked” reminds individuals that although daytime temperatures may still be warm, evenings can become quite cool, and going without adequate clothing can lead to catching a cold. Additionally, people are advised to take precautions against autumn dryness during this season.

Various regional customs and traditions are associated with “White Dew,” including rituals to honor historical figures like Great Yu the Great (大禹), the brewing of grains into alcoholic beverages, and the consumption of “White Dew Tea.”

“White Dew” is one of the 24 solar terms in the Chinese calendar, marking important transitions in natural rhythms and serving as the basis for establishing the “Twelve Earthly Branches.” These solar terms help people understand and adapt to seasonal changes, and they carry cultural and historical significance in Chinese society.

white dew history

“White Dew” is one of the 24 solar terms in China, originating from ancient Chinese agricultural culture. The origin of “White Dew” can be traced back to ancient agricultural societies where people observed natural phenomena and the growth of crops, developing a set of seasonal concepts to guide farmland management and agricultural timing.

In ancient China, agriculture was the primary means of production, and agricultural activities were crucial for managing farmland and determining the timing of crop planting. “White Dew,” as a solar term in the autumn, signifies gradually cooler weather and an increase in dew. It’s an important period for crops, particularly rice, as they start to be soaked in dew.

The name “White Dew” for this solar term originates from ancient Chinese observations and understanding of autumnal dew. The term “白” (white) refers to the clear and glistening appearance of dewdrops on leaves in the early morning, resembling white mist. “露” (dew) refers to the phenomenon where water vapor in the air condenses into dewdrops during cool autumn weather. Therefore, “White Dew” signifies cool autumn weather with abundant dew, which is beneficial for crop growth.

Ancient farmers used the arrival of the “White Dew” solar term to assess the growth status of crops in their fields and to plan agricultural activities such as harvesting and land cultivation. Today, “White Dew” remains an important element in Chinese traditional culture and is still reflected in folklore and daily life. It serves as a reference point for farmland management and agricultural timing.

The “White Dew” astronomical calendar

“White Dew” marks the beginning of the “You” month in the Chinese traditional calendar. The twenty-four solar terms and the twelve Earthly Branches are fundamental components of this calendar system. In ancient times, the phases of the moon were calculated based on the movement of the Big Dipper’s seven stars. The specific star pointed to by the handle of the Big Dipper was called the “Dipper’s Mansion” (also known as the “monthly branch”). As recorded in the “Huainanzi · Instructions on Astronomy,” “The Emperor Zhang uses the four dimensions, calculating with the Dipper. The moon shifts by one mansion and returns to its place. In the first month, it points to Yin, and in the twelfth month, it points to Chou. It completes one cycle in a year and starts anew.” Here, the “Dipper” refers to the handle of the Big Dipper. The handle of the Big Dipper completes one rotation clockwise, constituting one “year” (known as a “jieqi”). The division of the “twelve monthly branches” is based on the “twenty-four solar terms,” with each month associated with a specific solar term. These are: Spring Begins (Lichun), Awakening of Insects (Jingzhe), Pure Brightness (Qingming), Start of Summer (Lixia), Grain Rain (Guyu), Lesser Heat (Xiaoshu), Start of Autumn (Li Qiu), White Dew (White Dew), Cold Dew (Hanlu), Start of Winter (Lidong), Major Snow (Daxue), and Minor Cold (Xiaohan), which correspond to the start of the months of Yin (Jieqi: Lichun), Mao (Jieqi: Jingzhe), Chen (Jieqi: Qingming), Si (Jieqi: Lixia), Wu (Jieqi: Guyu), Wei (Jieqi: Xiaoshu), Shen (Jieqi: Li Qiu), You (Jieqi: White Dew), Xu (Jieqi: Hanlu), Hai (Jieqi: Lidong), Zi (Jieqi: Daxue), and Chou (Jieqi: Xiaohan).

“White Dew” marks the end of the “Shen” month and the beginning of the “You” month in the Earthly Branches calendar. It occurs annually in the Gregorian calendar between September 7th and 9th when the Sun reaches 165 degrees of the ecliptic longitude.

Weather Changes in the White Dew Season

After entering the White Dew season, the summer monsoon gradually gives way to the winter monsoon, with cold air moving southward more frequently. Additionally, the position of the sun’s direct radiation on the Earth’s surface shifts southward, leading to shorter daylight hours and reduced sunlight intensity in the Northern Hemisphere. Nights are often clear with fewer clouds, allowing for rapid ground radiation cooling. Consequently, temperatures gradually drop, and there is a saying that goes, “One night cooler than the next” during the White Dew season.

Following the White Dew season, the temperature difference between day and night gradually widens. While daytime temperatures may still be relatively high around noon, there is a hint of coolness in the morning and at night. According to the “seasonal average temperature” standard proposed by modern scholar Zhang Baokun, when the seasonal average temperature falls within the range of 10-22°C, it is considered either spring or autumn. Following this standard, starting from the White Dew season, different regions in China gradually transition into autumn. During this time, the temperature difference between day and night in various parts of China can range from 8°C to 16°C, making White Dew a season with significant temperature variations.

Phenomena of White Dew Season

During the White Dew season, the scorching summer heat gradually subsides, making way for crisp and refreshing autumn weather. Fragrant osmanthus and cassia flowers bloom, and migratory birds like wild geese and swallows begin their southward journey to escape the cold. Various bird species also start storing food for the winter.

“Wild geese arrive, and the swallows return.” After White Dew, migratory birds, which are particularly sensitive to climate changes, collectively migrate. Wild geese start flying from the north to the south, while the swallows, which had arrived in the spring, now fly back north. All kinds of birds begin to stock up on food for the upcoming winter. There’s a folk saying: “On a White Dew autumn night, a line of geese flies south,” and “At the Beginning of Autumn, the cicadas lull us to sleep, and during Late Summer, sunflowers smile; White Dew welcomes back swallows and geese, while the Autumn Equinox brings the fragrance of cinnamon.”

White Dew is characterized by three sub-seasons:

The arrival of wild geese: Large wild geese and small geese (ducks) represent two different species. Wild geese fly north in February and return south in August.

The return of the swallows: Swallows, also known as “xuan niao,” arrive during the spring equinox and depart during the autumn equinox. They are birds from the north, bringing vitality as they migrate south. Now, their northward migration represents their return, marking the time when red flowers are half-fallen, and the leaves start to fall as the autumn winds blow.

Flocking birds store delicacies: This “delicacies” refers to food. “The Black Tortoise hides in the shade, and the vermillion bird returns with delicacies.” It signifies that various birds sense the arrival of cooler weather and start storing food for winter, like treasured feasts.

Agricultural Activities during White Dew

“White Dew” symbolizes the transition from hot to cool weather, with all things growing and gradually maturing as the cold sets in. During White Dew, it’s a busy time for agricultural activities across China. In the northeastern region, harvesting of millet, sorghum, and soybeans begins, and some areas start picking new cotton. Simultaneously, farmers prepare for winter by selecting and storing seeds for crops like cotton, corn, sorghum, millet, and soybeans, while also focusing on land preparation and fertilization, ensuring timely planting of wheat.

In North China, it’s a hectic time for autumn harvest. Various late-season crops have ripened and are ready for harvesting. While harvesting, farmers must also attend to tasks like manure application, plowing, and land leveling, preparing for the upcoming wheat planting season. In the Northwest, winter wheat sowing begins.

In the Southwest, White Dew is a busy time as well, with a rush to harvest rice and millet. Corn, sweet potatoes, and other late-autumn crops require extra attention in the fields to encourage early ripening and prevent damage from frost and cold. In Central China, it’s time to harvest late-season rice, with summer corn also being harvested. Cotton is picked in batches, and late-season corn requires enhanced water management. Besides these tasks, land leveling for wheat planting needs to be completed promptly.

After the White Dew season, cold air becomes more active, resulting in lower temperatures, which can affect the flowering and pollination of late-season rice. In regions like the Yellow River and Yangtze River valleys, as well as South China, it’s essential to take advantage of warmer temperatures for shallow water irrigation. During White Dew, South China experiences reduced sunlight compared to Late Summer, with frequent but light rain, often drizzling and continuous. Hence, there’s a farming proverb: “On a White Dew clear day, grains and rice shine like silver.” To address this, appropriate agricultural techniques should be employed to mitigate or prevent damage from autumn rain while also focusing on preventing and controlling diseases like rice blast and sheath blight.

Traditional Customs of White Dew

Collecting Clear Dew

In Chinese folklore, there is a custom of “collecting clear dew” during the White Dew season. Li Shizhen, a Ming Dynasty scholar, wrote in his “Compendium of Materia Medica”: “During the abundant autumn dew, it should be collected in plates, boiled like syrup, and consumed to ensure a long life without hunger.” “Autumn dew on top of a hundred herbs, when collected before it dries, can cure various ailments, quench thirst, make one feel light and satisfied, and enhance one’s complexion.” Therefore, collecting clear dew has become a special ritual during the White Dew period.

Drinking White Dew Tea

White Dew tea is made from tea leaves harvested during the White Dew season. Folk wisdom says, “Spring tea is bitter, summer tea is astringent; to enjoy tea, wait for autumn’s White Dew.” During this time, tea plants have gone through the hot summer, and just before and after White Dew is another ideal period for their growth. White Dew tea is neither as tender as spring tea nor as dry and bitter as summer tea. It has a slightly roasted flavor, appreciated by seasoned tea drinkers. A sip of White Dew tea leaves a rich, mellow taste on the palate, making it a favorite among tea connoisseurs.

Eating Sweet Potatoes

Sweet potatoes are rich in proteins, starch, pectin, fiber, amino acids, vitamins, and various minerals, with a sugar content of 15% to 20%. They are known for their cancer-fighting, heart-protective, lung function improvement, and weight loss properties. In traditional Chinese medicine, sweet potatoes are considered a valuable food and are often referred to as “longevity food.” Li Shizhen’s “Compendium of Materia Medica” states, “Sweet potatoes nourish deficiencies, invigorate the spleen and appetite, and strengthen kidney yin.” It was a tradition in rural households to eat sweet potatoes during the White Dew festival as it was believed to prevent post-meal acidity.

Sipping Rice Wine

In the region of Zixing, Hunan, including Xingning, Sandu, and Liaojiang, there is a long-standing tradition of making and consuming rice wine during the White Dew festival. The wine is made from glutinous rice, sorghum, and other grains, and it is mildly warm and slightly sweet, known as “White Dew rice wine.”

Jiangsu and Zhejiang also have customs of brewing their own White Dew rice wine. In the past, rural families in the Suzhou and Zhejiang areas would make wine every White Dew season to serve guests, and some people would bring White Dew rice wine to the cities. Even into the 1930s and 1940s, there were still jars of White Dew rice wine in hotels in Nanjing, although it gradually disappeared.

Worshipping Lord Yu

In the Taihu Lake region of Jiangsu, local people hold ceremonies to worship Lord Yu during the White Dew season. Lord Yu is the legendary hero who controlled floods, and the fishermen living by Taihu Lake refer to him as the “Waterway Bodhisattva.” Every year on the 8th day of the first lunar month, Qingming, the 7th day of the seventh lunar month, and during White Dew, a grand incense ceremony is held. Among them, the Qingming and White Dew ceremonies are the largest, lasting for about a week.

Eating Longan

In Fuzhou, Fujian, there is a traditional custom called “eating longan during White Dew.” Folklore suggests that eating longan on this day has miraculous effects on nourishing the body. Longan is known for its ability to invigorate qi, nourish the spleen, nourish blood, calm the mind, and improve skin texture. It can also be used to treat various conditions such as anemia, insomnia, and nervousness. Longan harvested just before White Dew is known for its large size and sweet taste, making it an ideal choice for this tradition.

Ten White Herbs

In Zhejiang, Wenzhou, and other areas, there is a custom of collecting “Ten White Herbs” (or sometimes “Three White Herbs”) during the White Dew festival to be used in simmering a dish of black-boned chicken or duck. It is believed that consuming this dish can nourish the body and alleviate joint pain. The “Ten White Herbs” include 10 types of herbs with the word “白” (white) in their names, such as white hibiscus and white hairy beggarticks, corresponding to the “白露” (White Dew) in the name of the festival.

Autumn Harvest Festival

The Autumn Harvest Festival, also known as “秋社” (Qiu She), is a traditional celebration of the harvest season. It involves worshipping the earth god and expressing gratitude for a bountiful harvest. In ancient times, people believed in the connection between the land and their well-being, so they held these festivals during planting and harvesting seasons. The Autumn Harvest Festival usually falls around the White Dew period, and it is a joyful occasion to celebrate the abundance of the season and pay respects to the deities.

White Dew Daily Life

During the White Dew season, there is a significant temperature difference between morning and evening, so it’s essential to dress appropriately. There’s a saying, “Don’t expose your body during White Dew,” which reminds people that even though the daytime weather is mild, the mornings and evenings can be cool. Exposing your body can lead to catching a cold. In terms of diet, it’s essential to pay attention to what you eat. The “Nanjing Record” states, “People rely on food and drink to live, and the flavors of the five grains nourish the skin, fill the body, and moisten the hair.” This emphasizes the importance of preventing dryness during this season, as dryness can harm the body. To prevent dryness, it is advisable to consume foods rich in vitamins and traditional Chinese medicine that can moisten the lungs and nourish yin.

The “Clear Jia Record” records a saying: “It is said, ‘Don’t expose your body during White Dew.’ This means that even though the daytime weather is still warm, the mornings and evenings are already cool. If you go shirtless, you are likely to catch a cold. Also, during this season, it’s important to prevent autumn dryness.” “Covering up in spring and exposing less in autumn” is a classic health-preserving principle. However, it’s important to note that not everyone should follow the “exposing less in autumn” principle. People with weak constitutions, such as the elderly, children, individuals with cardiovascular diseases, chronic bronchitis, asthma, or arthritis, are not suitable for exposing themselves to cold weather in autumn.

White Dew Health and Wellness

White Dew marks the beginning of the truly cool season, and many people focus on nourishing their bodies with seafood and meat while neglecting seasonal health issues. This can lead to health problems for themselves and their families. People with allergies that cause respiratory problems should avoid or limit the consumption of seafood, especially fish, crabs, shrimp, chives, peppers, and other similar foods. Instead, they should opt for a light, easily digestible diet rich in vitamins.

Regularly opening windows and ventilating your living space is essential to maintain clean and fresh indoor air. Avoid going to areas with severe air pollution, and if there is morning fog, try to avoid going outside, especially for exercise.

Recommended Foods during White Dew

During the White Dew season, it’s important to focus on foods that can prevent nasal and respiratory diseases, asthma, and bronchial diseases. Emphasize a diet that nourishes the lungs and moistens dryness. It’s advisable to consume foods and fruits that can nourish the lungs and moisten dryness, such as snow pears, sugarcane, persimmons, water chestnuts, tremella mushrooms, pineapples, bird’s nests, pig lungs, honey, black chicken, soft-shelled turtles, duck eggs, and more. Smokers should consume foods rich in vitamins and supplement their diets with foods like milk, carrots, peanuts, cornmeal, and vitamin supplements. Additionally, consume foods high in vitamins regularly, such as bean sprouts, cabbage, and vegetable oil, to replenish vitamins.


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