Introduction to Medicinal Diet
Er Dong Old Duck Soup (二冬老鸭汤) is a traditional nourishing medicinal food originating from the Jiangnan region of China. It is named after its two key ingredients: Tian Dong (Asparagus cochinchinensis, asparagus root) and Mai Dong (Ophiopogon japonicus, dwarf lilyturf root), and has a long history in dietary therapy. This soup is made primarily with old duck, supplemented by the two yin-nourishing herbs Tian Dong and Mai Dong, along with small amounts of fresh ginger (Zingiber officinale, ginger root), goji berries (Lycium barbarum, wolfberry), and other adjuncts, all slow-cooked until tender. The resulting broth is clear and aromatic, with a delicious flavor. The duck meat is tender and moist without being greasy, and the herbal aroma blends perfectly with the savory taste of the meat. It serves both as a flavorful dish and a gentle, nourishing tonic.
In traditional culinary culture, old duck soup itself is regarded as a superior tonic for clearing heat and nourishing the body. The addition of Radix Asparagi (Tian Dong) and Radix Ophiopogonis (Mai Dong) further enhances its effect of moistening the Lung and nourishing Yin. This medicinal dish is especially suitable for consumption during the dry autumn or winter seasons, effectively alleviating various discomforts caused by Dryness pathogen injuring Yin. The Er Dong Old Duck Soup features a precise formula composition and mild ingredients, embodying the TCM principle of “medicine and food sharing a common origin,” making it an ideal choice for daily health regulation.
Efficacy of Medicinal Diet
The main effects of Er Dong and Old Duck Soup can be summarized as nourishing yin and moistening the lung, clearing heat and reducing fire, and generating fluids and quenching thirst. It provides good relief for symptoms such as dry cough with scant sputum, dry and sore throat, hoarse voice, and dry skin caused by yin deficiency with internal heat. At the same time, it also helps improve issues like dry mouth and tongue and dry stools due to insufficient body fluids, thereby restoring normal fluid metabolism.
Long-term consumption of Erdong Old Duck Soup (Radix Asparagi and Radix Ophiopogonis with Old Duck) can enhance the body’s immune function and delay aging. The duck meat in the soup is rich in high-quality protein and various trace elements, which are easily absorbed by the body, providing beneficial restorative effects for conditions such as post-illness weakness and postpartum blood deficiency. Additionally, this soup has certain regulating effects on symptoms of yin deficiency with effulgent fire (yin xu huo wang), such as irritability, insomnia, soreness and weakness of the lower back and knees, and tidal fever with night sweats, which are common in modern people due to staying up late, excessive mental exertion, and high work stress.
Protective effect on the respiratory system
Er Dong Old Duck Soup has particular nourishing and protective value for the respiratory system. Both Asparagus cochinchinensis (Tian Dong) and Ophiopogon japonicus (Mai Dong) enter the Lung Meridian (LU), moistening Lung dryness and clearing Lung heat. They provide adjunctive treatment for symptoms such as dry cough and scanty, sticky sputum caused by conditions like chronic pharyngitis and bronchitis. The yin-nourishing effect of old duck further improves the internal environment as a whole, reducing the frequency of respiratory disorders.
The Role of Traditional Chinese Medicine
From the perspective of Traditional Chinese Medicine (TCM), the combination of ingredients in “Er Dong Lao Duck Soup” embodies the principle of “nourishing yin and moistening dryness, with mutual generation of metal and water”. Tian Dong (Asparagus cochinchinensis, Tian Dong) is sweet and bitter in taste, cold in nature, and enters the Lung and Kidney channels. It has the effects of nourishing yin, moistening dryness, clearing lung heat, and descending fire, with a particular ability to enrich Kidney yin. It is notably effective for dry cough, tidal fever, and night sweats caused by Lung-Kidney yin deficiency. Mai Dong (Ophiopogon japonicus, Mai Dong) is sweet and slightly bitter in taste, slightly cold in nature, and enters the Heart, Lung, and Stomach channels. It focuses on nourishing yin, clearing heat, moistening the lungs to stop cough, and benefiting the stomach to generate fluids. It also alleviates irritability and insomnia due to Heart yin insufficiency. When used together, these two herbs complement each other, making the effect of nourishing yin and moistening the lungs more comprehensive.
In the dietary therapy of Traditional Chinese Medicine, old duck is known as the “supreme yin-nourishing product.” Its meat is sweet and salty in flavor, neutral in nature, and enters the Spleen (SP), Stomach (ST), Lung (LU), and Kidney (KI) meridians. Duck meat can nourish yin and nurture the stomach, promote urination to reduce edema, and also tonify deficiency and clear heat, making it especially suitable for individuals with deficient heat in the body. When duck meat is paired with Er Dong (namely Tian Dong [*Asparagus cochinchinensis*, Asparagus Root] and Mai Dong [*Ophiopogon japonicus*, Dwarf Lilyturf Root]), the rich flavor of the duck carries the medicinal power deep into the interior, while the duck’s own yin-nourishing effect complements the herbs synergistically, enhancing the overall efficacy. The addition of fresh ginger warms the middle burner and disperses cold, removes the fishy taste of the duck, and moderates the cold nature of Er Dong, making the medicinal properties more balanced and suitable for long-term intake.
Indications
Er Dong Lao Ya Tang (Old Duck Soup with Asparagus Root and Ophiopogon) is most suitable for individuals with a Yin deficiency constitution. Such people typically present with a thin body build, heat in the palms and soles, dry mouth and throat, flushed complexion, red tongue with scant coating, and a thready, rapid pulse. For those who frequently experience dry cough with scant sputum, dry and sore throat, or hoarse voice, consuming this soup can significantly alleviate discomfort. It is also beneficial for individuals who smoke, drink alcohol long-term, or live in dry environments, as it helps moisturize the respiratory system and relieve issues such as chronic pharyngitis.
In addition, Asparagus and Ophiopogon Old Duck Soup (Er Dong Lao Ya Tang) is suitable for individuals recovering from illness, childbirth, or surgery, as well as modern urban populations experiencing high work pressure, frequent late nights, and mental overexertion. The elderly, who suffer from dry skin and constipation due to physiological depletion of body fluids (jin ye), can also benefit from consuming this soup to regulate their condition. Menopausal women presenting with hot flashes, night sweats, restlessness, and insomnia due to yin deficiency with fire hyperactivity (yin xu huo wang) may likewise find relief.
Contraindicated populations
Er Dong (Asparagus cochinchinensis and Ophiopogon japonicus) Duck Soup is cold and cool in nature. Therefore, it is not suitable for individuals with Spleen and Stomach Deficiency Cold or those experiencing loose stools. Such individuals typically present with cold pain in the abdomen, poor appetite, thin, unformed stools, a pale, puffy tongue with teeth marks, and a deep, slow pulse. Consumption may worsen these symptoms. People with Yang deficiency constitution, especially those who tend to feel cold, have cold hands and feet, clear and copious urine, and frequent nocturia, should also use caution to avoid damaging Yang Qi.
In addition, during a cold or fever, one should avoid consuming Er Dong Lao Ya Tang (Soup of Asparagus cochinchinensis [Tian Dong] and Ophiopogon japonicus [Mai Dong] with old duck), because at this time external pathogens are binding the exterior and healthy qi is struggling against pathogens, requiring dispersion and releasing the exterior (dispersing and exterior-releasing therapy), rather than supplementation and astringency (nourishing and astringent therapy). Individuals with internal exuberance of phlegm-dampness presenting with cough and copious clear thin phlegm, as well as patients with severe liver and kidney dysfunction, hyperuricemia, or acute gout attacks, should also avoid this soup. Pregnant women and infants should consult a professional TCM practitioner before consumption to ensure safety.
Ratio of Ingredients in the Formula
Preparation of Er Dong Lao Ya Tang (Two Winters Old Duck Soup) ingredients and proportions (for 4-6 servings): – Old duck: 1 (approx. 1500g, preferably a duck aged over two years for best results) – Asparagus cochinchinensis (Tianmen Dong, Asparagus Root): 15g – Ophiopogon japonicus (Maimen Dong, Dwarf Lilyturf Root): 15g – Fresh ginger: 20g (sliced) – Lycium barbarum (Goji Berry): 10g – Salt: to taste (approx. 5g, added at final seasoning) – Water: 3000ml (approx. 6 bowls)
In the above formula, 15 g each of “Two Winters” (Tian Dong: *Asparagi Radix*, Asparagus Root; Mai Dong: *Ophiopogonis Radix*, Ophiopogon Root) is the standard dosage. The medicinal properties are mild and suitable for most individuals. If yin deficiency symptoms are more pronounced, the dosage of each “Winter” can be increased to 20 g. The addition of Gou Qi Zi (*Lycii Fructus*, wolfberry) enhances the effect of nourishing the liver and kidney, while also adding a sweet and refreshing taste to the soup. For the old duck, it is best to select a Ma duck or Bai duck, as their flesh is firmer and more flavorful.
Preparation Method
Step 1: Prepare the ingredients. Kill and pluck the old duck, remove the internal organs, chop off the duck head and tail, wash thoroughly, then cut into pieces about 4 cm square. Quickly rinse Tian Dong (Asparagus cochinchinensis root) and Mai Dong (Ophiopogon japonicus root) with clean water to remove surface dust, then soak in warm water for 15 minutes. Slice fresh ginger (Zingiber officinale) and set aside. Briefly rinse the Goji berries (Lycium barbarum).
Step 2: Blanch to remove odor. Place the duck pieces in a pot of cold water, add 10 g of *Zingiber officinale* (ginger) slices (taken from the total amount), bring to a boil over high heat, skim off the foam, and continue boiling for about 3 minutes. Remove the duck pieces, rinse thoroughly with warm water, and drain well. This step effectively removes the fishy odor and blood from the duck meat, ensuring the soup remains clear and not cloudy.
Step 3: Slow simmering. Place the blanched duck pieces into a stewing pot, add Radix Asparagi (Asparagus Root), Radix Ophiopogonis (Ophiopogon Root), and the remaining ginger slices, then pour in 3000 ml of water. Bring to a boil over high heat, then reduce to low heat, cover with a lid, and simmer slowly for about 1.5 hours. During this time, avoid lifting the lid frequently to prevent the loss of aroma. When the duck meat becomes tender enough to be easily pierced with chopsticks, add Fructus Lycii (Goji Berries) and continue simmering for another 10 minutes.
Step 4: Season and serve. Five minutes before turning off the heat, add an appropriate amount of salt to taste (note: do not add salt too early, as it may affect the tenderness of the duck meat and the freshness of the broth). Stir well, then skim off any excess surface oil before ladling into bowls for serving. The soup will be golden and clear, the duck meat tender and falling off the bone, with a perfect fusion of medicinal aroma and meat fragrance, sure to whet the appetite.
Usage Tips
The consumption timing is important. Er Dong Lao Duck Soup (Asparagus cochinchinensis and Ophiopogon japonicus with old duck) is most suitable for autumn and winter, especially from the End of Heat (Chu Shu) solar term to the Start of Spring (Li Chun). It is recommended to consume it in the morning or at noon, when Yang Qi is at its peak and the body can better absorb the nourishing substances in the soup. Avoid eating too much in the evening to prevent increasing digestive burden and affecting sleep.
2. Consume in moderation. As a regulating medicinal diet, Erdong (Asparagus cochinchinensis and Ophiopogon japonicus) Old Duck Soup may be consumed 1–2 times per week, and should not be taken continuously for more than 4 weeks. If long-term use is required, it is recommended to take breaks or proceed under the guidance of a TCM practitioner. Each serving of soup and meat should be taken to a comfortable extent, without overconsumption.
3. Storage and Pairing Suggestions. When consuming Tian Dong & Mai Dong Old Duck Soup, it is recommended to simmer it with warming-natured ingredients such as Chinese yam (Dioscoreae Rhizoma) and lotus seed (Nelumbinis Semen) to balance the medicinal properties. Any leftover soup can be refrigerated for up to 2 days and must be brought to a full boil before consumption. However, note that repeated reheating will reduce the medicinal efficacy of the food remedy and may generate harmful substances. It is advisable to prepare only the amount needed each time and consume immediately after cooking.