Pakala Bhat: The Fermented Rice Probiotic associated with Lord Jagannath of Puri

Pakala Bhat, also known as Panta Bhat or Poita Bhat, is a traditional fermented rice dish from the eastern Indian states of Odisha, West Bengal, Assam, and Tripura, as well as parts of Bangladesh. The name varies by region: Pakala Bhat in Odia, Panta Bhat in Bengali, and Poita Bhat in Assamese. Unlike yogurt ferments or vegetable brines, Pakala Bhat is a simple water based fermentation of fully cooked rice submerged in water and left overnight or longer at ambient temperature. It is a staple comfort food during summer months and the Bengali New Year festival Pohela Boishakh, valued for its cooling effect on the body and its ability to prevent heat stroke and dehydration among agricultural workers.

Cultural Roots, Ingredients, and Microbial Ecology

Cultural Roots

Pakala Bhat has been consumed for over a thousand years in the Ganges Delta region, referenced in ancient texts as a food for laborers and travelers. Traditionally, the previous day’s leftover rice is submerged in water in an earthenware pot and kept in the warm kitchen or a shaded corner. The clay pot’s porous nature allows gentle evaporation, maintaining a lower temperature than the surroundings. The dish is typically eaten for breakfast with accompaniments such as raw onions, green chilies, roasted dried fish, pickles, or a mashed potato dish called Alu Chokha. The fermentation is entirely spontaneous, relying on naturally present lactic acid bacteria from the rice, water, air, and the clay vessel.

Raw Ingredients

· Cooked rice: Preferably a short grain, non aromatic variety like Indrayani, Banskathi, or Govindabhog

· Filtered non chlorinated water: Traditionally soft river or well water

· Salt: Occasionally added but traditionally omitted to favor microbial growth

· Optional additions: Curd (yogurt) as a starter culture, lemon juice

Microbes Isolated from Pakala Bhat

Scientific metagenomic and culture dependent studies have identified a diverse consortium of lactic acid bacteria and yeasts in traditionally fermented Pakala Bhat.

Lactic acid bacteria (LAB)

· Lactococcus lactis subspecies lactis

· Lactococcus lactis subspecies cremoris

· Leuconostoc mesenteroides

· Lactiplantibacillus plantarum

· Levilactobacillus brevis (formerly Lactobacillus brevis)

· Pediococcus pentosaceus

· Weissella confusa

· Enterococcus faecium

· Lactobacillus curvatus

Yeasts (contributing to aroma and vitamin production)

· Saccharomyces cerevisiae

· Pichia kudriavzevii

· Candida parapsilosis

Acetic acid bacteria (in longer fermentations)

· Acetobacter orientalis

· Acetobacter pasteurianus

Approximate CFU per gram

A well fermented Pakala Bhat contains between 10⁷ and 10⁹ colony forming units per gram of solid rice. The liquid phase (the starchy water known as torani or gheil) contains comparable counts. Within 6 to 12 hours of ambient temperature fermentation (25 to 35 degrees Celsius), LAB counts reach 10⁸ CFU per gram, exceeding the probiotic threshold of 10⁶ CFU per gram. Yeast populations typically range from 10⁵ to 10⁶ CFU per gram.

Preparation Guidelines

Raw Materials and Quantities for 500 Grams of Cooked Rice (serves 2 to 3)

Cooked rice (plain, unsalted)

Quantity: 500 grams, approximately 3 cups, preferably leftover or freshly cooled

Filtered non chlorinated water

Quantity: 750 ml to 1 liter, enough to fully submerge rice plus 2 cm above

Earthenware or glass vessel

Quantity: 1 pot of 2 liter capacity

Salt (optional for taste after fermentation)

Quantity: To taste

Yogurt starter (optional for faster fermentation)

Quantity: 1 tablespoon per 500 grams rice

Pre processing Guidelines

Rice preparation

Cook rice with no salt, no oil, and no turmeric. The rice should be fully cooked but not mushy; individual grains should remain distinct. Allow the rice to cool to room temperature, ideally 25 to 30 degrees Celsius. Do not refrigerate before fermentation as chilling slows initial microbial activity.

Water preparation

Use boiled and cooled filtered water or clean well water. Chlorinated tap water will inhibit or kill the desired lactic acid bacteria. The water should be at room temperature.

Vessel selection

Use a clean unglazed earthenware matka or a sterilized glass jar. Earthenware is traditional because its porous structure and residual microbial biofilm from previous batches accelerate fermentation. If using a new clay pot, soak it in water overnight and allow it to dry. For glass jars, sterilize with boiling water.

Step by Step Recipe

1. Place rice in vessel: Transfer the cooled cooked rice into the clean pot or jar. Spread it evenly rather than packing tightly.

2. Add water: Pour the room temperature filtered water slowly over the rice until all grains are fully submerged. The water level should stand approximately 2 cm above the surface of the rice.

3. Optional starter addition: If using yogurt starter, mix 1 tablespoon of fresh curd into the water and stir gently.

4. Cover appropriately: Cover the vessel with a muslin cloth or a loose fitting lid. Do not seal airtight as the fermentation produces carbon dioxide and requires oxygen exchange for yeast activity.

5. Ferment: Keep the vessel in a warm shaded spot away from direct sunlight. The ideal ambient temperature range is 25 to 35 degrees Celsius. Fermentation time varies with temperature.

6. Check at 6 hours: At 25 degrees Celsius, mild fermentation begins at 8 to 10 hours. At 35 degrees Celsius, significant fermentation occurs within 4 to 6 hours. Tiny bubbles appear on the surface, and the water turns slightly milky or cloudy.

7. Optimal fermentation window: For a mildly sour, refreshing taste, ferment for 8 to 12 hours. For a more acidic, tangy, and effervescent product, ferment for 16 to 24 hours. Beyond 24 hours, the pH drops below 4.0, and the rice becomes very soft; beyond 48 hours, acetic acid bacteria may produce a vinegar like note.

8. Signs of readiness: The rice grains appear swollen and easily separable. The liquid (torani) becomes opaque, milky white, and slightly viscous. The aroma is pleasantly sour and yeasty, similar to sourdough or plain yogurt. The pH decreases from an initial value near 6.2 to approximately 3.8 to 4.2 after 12 hours and 3.4 to 3.8 after 24 hours.

9. Store: Pakala Bhat is best consumed within 12 to 24 hours of fermentation for optimal flavor and probiotic content. If refrigerated, fermentation slows dramatically, but live counts decline over 48 to 72 hours. Consume within 1 day of refrigeration for best results.

Serving Suggestion

Strain the torani liquid into a separate cup. Serve the fermented rice in a bowl, topped with a splash of the torani. Traditional accompaniments include chopped raw onion, sliced green chili, mustard oil, a pinch of salt, and a wedge of lemon. The torani itself is drunk as a probiotic rehydration beverage.

Medicinal and Nutraceutical Benefits

Pakala Bhat functions as both a functional food and a traditional oral rehydration therapy. Its benefits derive from live probiotics, postbiotic metabolites, and the physical properties of fermented starch.

Contribution of Probiotics

Gut microbiome restoration

Lactococcus lactis and Leuconostoc mesenteroides dominate the early fermentation and demonstrate high bile salt tolerance. These strains survive gastric transit and colonize the small intestine, reducing diarrhea causing pathogens. Research has documented that Pakala Bhat consumption significantly reduces the duration of acute diarrhea in children, comparable to standard oral rehydration solutions.

Heat stroke and dehydration prevention

The fermented rice water (torani) contains electrolytes, including potassium, sodium, and magnesium, along with glucose and amino acids. Its low pH and organic acid content enhance fluid absorption in the small intestine through sodium glucose cotransport mechanisms. Agricultural workers in eastern India traditionally drink torani during peak summer hours to prevent heat exhaustion.

Immunomodulation

Regular consumption increases salivary immunoglobulin A and reduces markers of systemic inflammation including C reactive protein. The microbial diversity of Pakala Bhat, containing both LAB and yeasts, provides broader immune stimulation compared to single strain probiotics.

Antimicrobial activity against enteropathogens

Studies have demonstrated that the cell free supernatant of Pakala Bhat fermented for 24 hours shows strong inhibition against Vibrio cholerae, enterotoxigenic Escherichia coli, Shigella flexneri, and Salmonella Typhimurium. The inhibition zone diameters range from 12 to 18 mm, attributed to lactic acid, acetic acid, and bacteriocin like substances.

Vital Postbiotics and Bioactive Metabolites

Lactic acid and acetic acid

These organic acids lower intestinal pH to 4.0 to 4.5, creating an unfavorable environment for pathogenic bacteria while preserving beneficial species. Acetic acid specifically inhibits gram negative enteric pathogens.

Short chain fatty acids (SCFAs)

Fermentation of rice starch produces butyrate, propionate, and acetate in significant quantities. Butyrate serves as the primary energy source for colonocytes, strengthens the tight junction proteins of the gut barrier, and exerts anti inflammatory effects in the colonic mucosa.

Exopolysaccharides (EPS)

Lactococcus lactis strains from Pakala Bhat produce heteropolysaccharides that function as prebiotics and demonstrate cholesterol lowering activity in vitro, with reported reductions of 15 to 22 percent in LDL cholesterol.

Gamma aminobutyric acid (GABA)

Levilactobacillus brevis and certain yeast species convert glutamate to GABA during fermentation. Pakala Bhat fermented for 24 hours contains measurable GABA levels of 15 to 25 mg per 100 grams, associated with mild anxiolytic and blood pressure lowering effects.

Bioactive peptides from rice proteins

Proteolysis during fermentation releases angiotensin converting enzyme (ACE) inhibitory peptides and antioxidant peptides from rice glutelin and prolamin fractions. These contribute to mild antihypertensive effects.

Resistant starch formation

The cooling of cooked rice followed by fermentation increases resistant starch type 3 (retrograded starch) content by 30 to 50 percent compared to freshly cooked rice. Resistant starch escapes small intestinal digestion, reaching the colon where it serves as a prebiotic substrate for butyrate producing bacteria.

Additional Nutraceutical Highlights

Antioxidant activity

Total phenolic content increases by 40 to 60 percent during 24 hours of fermentation due to microbial release of bound phenolics from rice bran. The dominant phenolic acids include ferulic acid, p coumaric acid, and vanillic acid.

Vitamin enrichment

Fermentation enhances B vitamin concentrations. Research has documented increases of 2 to 4 fold for riboflavin (B2) and niacin (B3), and a 3 to 5 fold increase for folate (B9). Certain yeast strains produce detectable levels of cobalamin (B12).

Low glycemic index

The combination of acidification, resistant starch formation, and the presence of organic acids reduces the glycemic response to Pakala Bhat compared to fresh rice. In vivo studies show a 25 to 30 percent lower postprandial glucose spike.

Antidiarrheal mechanism beyond probiotics

The starchy torani liquid acts as a prebiotic rich mucoadhesive, coating the intestinal lining and reducing pathogen adhesion. This physical barrier effect complements the antimicrobial action of organic acids and bacteriocins.

Comparison with commercial oral rehydration solutions

Traditional torani contains potassium (approximately 15 to 20 mmol/L), sodium (10 to 15 mmol/L), glucose (from starch breakdown), and amino acids, providing a natural hypotonic rehydration fluid. While commercial oral rehydration solutions have precisely controlled sodium levels for severe dehydration, torani offers additional probiotic and anti inflammatory benefits for mild to moderate dehydration and diarrhea prevention.

Usage Note

Pakala Bhat is safe for most individuals. Because it contains histamine and tyramine from fermentation, those with histamine intolerance, monoamine oxidase inhibitor (MAOI) medication use, or severe mast cell disorders should start with a small portion of 50 grams. The dish is naturally low in salt unless added after fermentation, making it suitable for low sodium diets. Avoid if the fermentation produces off odors like ammonia or putrefaction, which indicates contamination.

Enjoy Pakala Bhat as a cooling breakfast during hot weather, as a post work rehydration meal, or as a gentle probiotic food for recovery from diarrhea or antibiotic use. The torani liquid can be consumed on its own as a probiotic shot of 100 to 150 ml.