The Sacred Stem: Bengali Thor Chhenchki Recipe, Maritime Rituals, and the Indigenous Science of Kolakhar
After removing the layers of the hard outer stem of the banana tree, the tender fibrous inner pith of the stem or core contains many medicinal properties and is very beneficial to health. It is edible and commonly chopped and cooked as a vegetable served with rice in many Bengali households.
Banana plants play an important role in Bengali kitchens and rituals. While the fruit is widely consumed, the inner stem or thor is also used to prepare traditional dishes such as thor chhenchki. Beyond cooking, different parts of the banana plant have been used historically in rituals, agriculture, and indigenous food science. From vegetables like thor chhenchki to alkaline mineral extracts such as kolakhar, the plant continues to play an irreplaceable role in regional culinary traditions.
1. Technique: Slicing the Fibrous Plantain Stem (Thor)
The inner core of the banana plant is tightly bound with strong, fine natural fibers. If chopped without care, the sticky fibers snag against the knife edge and fingers.
The Oil-Rub Technique: Rub your hands thoroughly with a few drops of mustard oil or cooking oil prior to cutting the stem. Cut thin round slices across the stem. As you slice, the fine natural fibers catch effortlessly around your oily fingers in smooth loops, allowing you to peel them away cleanly. Once de-fibered, stack the round discs and cut them into long, fine matchstick strips (julienne cut). There is no need to wash the stem again once cut.
2. Thor Chhenchki – Traditional Bengali Recipe
Traditional Bengali thor chhenchki is prepared from finely chopped plantain stem, fresh coconut, and an aromatic tempering of kalonji and mustard seeds.
3. The Banana Plant in Rituals - Maritime Navigation of Bengal
The banana plant has been an important part of Bengali culture and ritual life for centuries. The utilization of hemp fibers of the banana stem started almost since 4000–3000 B.C. Kola is in the Bengali vernacular used for the fruit Musa paradisiaca. Fruits are offered in puja and the stems are used for ceremonial decoration.
Worship of the goddess of wealth, Lakshmi, which is observed during the months of October or November (Kojagari Lakshmi Puja), comprises meaningful symbolic decorations: boats made out of hollowed-out portions of the stem of the sacred plantain tree. These boats are decorated with colored paper and flowers, then filled with crops like paddy, certain pulses, bananas, and sugar candies.
These miniature boats are placed to invoke the blessing of Goddess Lakshmi as having reached our home to bless us with wealth. This custom recalls the traditional navigation and voyages of Bengal traders (Sadhabas) who returned safely with wealth from Ceylon (Sri Lanka) or Java after a season of good business. Evidence from historical notes suggests that traditional navigation forwarded social and religious festivals, carried out as a seasonal phenomenon.
Seasonal monsoon winds historically guided maritime trade across the Bay of Bengal. Traders from Bengal and Orissa sailed with the northeast monsoon and returned home with the southwest winds. These voyages influenced regional festivals such as Kojagari Lakshmi Puja and Kartik Purnima, celebrating safe journeys, return of the merchant boats, and maritime prosperity.
4. Kolakhar: The Living Magic of Banana Ash in Rural Kitchens
Across villages and tribal communities in Assam, nothing from the land ever goes to waste. When a banana tree gives its harvest of fruit, its life is far from over. From its trunk, roots, and sun-dried peels comes Kolakhar—a dark, fragrant, mineral-rich liquid that has served as medicine, soap, cooking salt, and stomach healer for generations[cite: 1]. It is simple, natural chemistry practiced not in laboratories, but around the winter courtyards and open hearths of village homes.
Plants absorb minerals from the soil, and when incinerated their ashes produce important compounds such as Yavakshara or Darulawana (impure potash carbonate). Succulent plants contain a larger proportion of it than their woody counterparts. The existence of impure potassium carbonate has been known since ancient times, wood ash being its principal source in India.
5. The Science of Athia Kal (Musa balbisiana) - Laboratory Extraction
Among the different species of banana plants, Musa balbisiana (the seedy variety, locally known as Athia Kal or Bhimkol) is considered the best for preparing Kolakhar[cite: 1].
Laboratory Methodology: During chemical studies at Gauhati University, ashes were extracted using distilled water[cite: 1]. A weighed quantity of ash was suspended in distilled water (20 ml per gram of ash) in a glass beaker and stirred with a mechanical stirrer for 45 minutes[cite: 1]. The mixture was then filtered through a sintered glass crucible under suction, and the clear filtrate was analyzed as Kolakhar[cite: 1].
Chemical and spectroscopic investigations confirm the presence of potassium, sodium, chloride, and carbonate as the major constituents, along with a host of trace elements, while sulfate, bromide, and iodide were absent[cite: 1].
Why Ancestors Preferred the Seedy Variety (Bhimkol) Over Seedless Varieties:
- Highest Carbonate - Potassium in Peels: Kolakhar prepared from banana peels contains significantly higher amounts of carbonate (161.40 g/kg ash) and potassium (233.60 g/kg ash) compared to other parts[cite: 1]. While inflorescence also has high levels, it is reserved for cooking as a vegetable and rarely used for ash[cite: 1].
- Much Lower Lead Levels: Lead is substantially lower in Kolakhar derived from the seedy variety Musa balbisiana (0.005–0.007 ppm) compared to seedless cultivars (0.42–0.67 ppm)[cite: 1]. This explains why community elders strictly avoided commercial eating bananas for making medicinal Khar[cite: 1].
- High Aluminum (Natural Antacid): The aluminum level is much higher in the seedy variety (8.13–8.77 ppm) compared to seedless varieties (0.36–1.68 ppm)[cite: 1]. This provides an added therapeutic advantage when used as an antacid to normalize stomach disorders[cite: 1].
- Cardioprotective Vanadium: Vanadium is present in notable amounts in Kolakhar (up to 5.59 ppm)[cite: 1]. Vanadium is believed to play a beneficial role in the prevention of heart diseases; geographical areas with low incidences of heart disease (such as New Mexico) consistently show higher natural vanadium levels in local drinking supplies[cite: 1].
6. Vedic Fire Offerings - Traditional Ash Science
It is recorded that in Vedic days, monks and rishis performed sacred fire sacrifices (Yajna) during the months of Magha and Falgun to rid the mind of unfulfilled desires. People moved around the bonfire seven times, chanting hymns and sounding God's name, while throwing vegetables—including brinjal, potato, cabbage, tomato, and banana—into the flames.
At the conclusion, the priest pacified the fire by sprinkling sacred Panchamrit (a mixture of milk, curd, ghee, honey, and sugar). People searched out the charred vegetables from the ashes as sacred prasad, besmeared a portion of the holy ash on their foreheads, and on the following day, sprinkled this mineral ash across their crop fields for a better harvest. Modern agricultural science confirms that incinerating succulent vegetables produces potent potassium- and carbonate-rich alkaline ash that sweetens acidic soil and boosts plant vigor[cite: 1].
Indigenous Bean Processing: Banana peel ash extract is widely used by rural folk in indigenous cooking of dry, hard-to-cook beans. Scientific evaluation shows that it reduces the cooking time of beans by nearly 50%. The peel ash extract contains substantial amounts of sodium (0.36 g/ml), chloride (0.07 g/ml), and magnesium (0.04 g/ml) ions, alongside detectable calcium, iron, copper, and zinc. Taste, tenderness, and acceptance scores are substantially higher in beans cooked with banana ash extract than in those cooked with ordinary water.
7. The Thor Theorem: Natural Salt Substitute - Industrial Potash
Analysis of Kolakhar demonstrates that potassium carbonate is present in significant quantities[cite: 1]. In nature, potassium carbonate is practically non-existent except for minor sources in a few African lakes and the Dead Sea[cite: 1]. Industrially, it is manufactured by absorbing carbon dioxide in potassium hydroxide—which requires energy-intensive electrolysis of potassium chloride[cite: 1].
Therefore, a renewable natural source of potassium carbonate is highly desirable[cite: 1]. With as high as 233 g of potassium and 161 g of carbonate per kg of ash, Kolakhar provides an ideal, cheap, renewable alternative[cite: 1]. After harvesting fruit, banana plants are otherwise discarded as agro-waste[cite: 1]. Every kg of ash yields 200 to 300 g of potassium carbonate, which can be extracted from just 5 to 8 kg of air-dried plant matter[cite: 1].
The Salt Substitute for Hypertension: Global diets high in ready-to-eat salty foods increase health risks, especially high blood pressure caused by excessive sodium chloride (table salt). Health authorities recommend consuming no more than 2,300 mg of sodium per day, against 4,700 mg of potassium—more than twice as much potassium as sodium.
An excellent natural salt substitute derived from Musa balbisiana ash replaces sodium chloride with potassium chloride and potassium carbonate. It contains nearly 46% potassium and only 2.6% sodium, matching the ideal mineral proportions found in nature and providing flavor while lowering sodium intake and helping manage blood pressure.
8. Everyday Community Uses: Cooking, Antacid, Soap and Soil
In Assam, traditional use of herbal medicine by the Madahi tribe of Nalbari district includes signature dishes like Omita Khar (raw papaya cooked with Kolakhar). Across rural communities, Kolakhar serves multiple vital functions:
- Digestive - Antacid: Normalizes digestive disorders, neutralizes hyperacidity, and relieves heartburn[cite: 1].
- Traditional Soap -Shampoo: In ancient Assam, Kolakhar was widely used as soap and detergent for washing clothes and shampooing hair[cite: 1]. Rural women have maintained long, healthy hair using Kolakhar alone, as its alkaline nature dissolves scalp dirt and grease without artificial chemicals[cite: 1].
- Antiseptic - Wound Healing: Applied to freshly cut injuries to prevent bacterial attack and accelerate wound healing[cite: 1].
- Leech Repellent: Farmers apply it to kill leeches and prevent their bites while working in leech-infested paddy fields[cite: 1].
- Veterinary Medicine: Used for the prevention and treatment of specific cattle ailments[cite: 1].
- Potassium Fertilizer: The spent ash residue is spread directly onto acidic agricultural soils as an organic potassium-type fertilizer to sweeten the earth and enhance crop yields[cite: 1].
From comforting dishes like thor chhenchki to the medicinal power of kolakhar, these practices connect seasonal cooking, health knowledge, and sacred rituals that continue to enrich the cultural heritage of Eastern India.
9. Frequently Asked Questions (FAQ)
Why should I rub cooking oil on my hands before cutting plantain stem (thor)?
Plantain stem contains natural sap and fine, web-like fibers that stick to the knife and fingers and oxidize into dark stains. Rubbing a few drops of cooking oil on your hands prevents the fibers from adhering, allowing them to wrap cleanly around your fingers in smooth loops as you slice.
What is Kolakhar, and how is it traditionally made?
Kolakhar is an indigenous alkaline liquid extract prepared by sun-drying the trunk, rhizomes, and peels of the banana plant (especially the seedy Musa balbisiana) over several weeks during winter[cite: 1]. The dried pieces are burned to ash, placed in a bamboo filter, and percolated with water to extract a clear, amber potassium carbonate solution[cite: 1].
Why is the seedy banana (Musa balbisiana) superior to seedless table varieties?
Chemical studies show that Musa balbisiana contains significantly higher levels of potassium carbonate and natural antacid aluminum, while having far lower levels of toxic lead (0.005–0.007 ppm) compared to common seedless varieties (0.42–0.67 ppm)[cite: 1]. It also contains cardioprotective trace vanadium[cite: 1].
How did banana plants connect to ancient maritime trade and Lakshmi Puja?
During Kojagari Lakshmi Puja and Kartik Purnima, households carve ceremonial boats from buoyant banana stems, filling them with paddy, pulses, and sweets. This invokes Goddess Lakshmi and preserves memories of Bengali merchants (Sadhabas) who sailed with the northeast monsoon winds to Ceylon and Java and returned safely with wealth on the southwest winds.
Can Kolakhar be used as a salt substitute?
Yes. Banana plant extract offers an organic salt substitute consisting of approximately 46% potassium and only 2.6% sodium. This potassium-to-sodium ratio supports healthy blood pressure regulation by significantly cutting down on table salt (sodium chloride) consumption.
Reference
Deka, D. C., and Talukdar, N. N. (2007). Chemical and spectroscopic investigation of Kolakhar and its commercial importance. Indian Journal of Traditional Knowledge, 6(1), 72–78.