A Comprehensive Guide to Probiotic and Fermented Foods of Assam

Assam, a state in Northeast India, is home to a remarkable diversity of tribal communities, each with a deep, traditional knowledge of food fermentation. This knowledge, often passed down through generations within families, uses naturally occurring microorganisms to preserve food, enhance flavor, and improve digestibility. The resulting fermented foods and alcoholic beverages are rich in probiotics, primarily lactic acid bacteria, yeasts, and beneficial molds. This document organizes these foods into two main categories: those requiring a specialized starter culture and those that rely on spontaneous or back-slopping fermentation.

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Part 1: Starter Cultures for Alcoholic Beverages (Rice Beers)

The most complex and sacred fermented products are rice beers. They are made using dry, cake-like, or powdered starter cultures. Each tribe has a unique name for its starter and a secret blend of local plants and rice flour. These starters contain a consortium of amylolytic molds (like Rhizopus), starch-fermenting yeasts (including Saccharomyces and non-conventional yeasts like Pichia), and lactic acid bacteria.

Ahom Community: Vekur Pitha (also called Likhar Pitha)

This starter is a rice-based cake. Its most crucial ingredient is the plant 'Vekur' (Clerodendrum viscosum). Other wild herbs, including jackfruit leaves, black pepper leaves, and roots of Alpinia species, are added to rice flour to form the cakes. These cakes are used to brew the Ahom community's traditional rice beer.

Mising (Mishing) Community: Apong Pitha (or Opop Pitha)

This is a powdered starter made from rice flour and a complex mixture of local herbs. Key herbs include Oldenlandia corymbosa (known locally as Bon Jaluk), Clerodendrum species, and Artemisia species. The exact recipe is often a family secret, varying from village to village. It is used to make Apong, the traditional Mising rice beer.

Karbi Community: Thap

This is a dry, cake-like starter. It is named after its primary botanical ingredient, the leaf of the Thap plant (Albizia myriophylla). The leaves are mixed with rice flour and a small amount of a previous successful starter to create the cakes. This starter is used for brewing Hor Alank, the Karbi rice beer.

Bodo Community: Amao or Emaw

This starter is essential for brewing Jou, the Bodo rice beer. It is made by grinding local rice with specific wild herbs. The most critical ingredient is the root or leaf of the Amao plant, a variety of wild pepper. Other ingredients typically include jackfruit leaves (Artocarpus heterophyllus).

Dimasa Community: Humao (or Humao Bakhor)

This is a rice flour based starter for their traditional rice beer, Judima. It is made by crushing rice with the bark and leaves of the Thembra plant (Acacia pennata), and sometimes ginger. These plant materials are known to be rich in wild yeasts and amylolytic fungi, which drive the fermentation.

Rabha Community: Phap or Bakhor

This starter cake is used for brewing Choko, the Rabha rice beer. It is made from glutinous rice flour and a mixture of seven to fifteen different wild medicinal plants. A key ingredient is Clerodendrum infortunatum. The diversity of plants contributes to the beer's unique flavor profile.

Tiwa (Lalung) Community: Chuwar Pitha

This starter is used for their rice beer called Chu. The cake is made from fermented rice flour mixed with the roots and leaves of specific wild plants, most notably a plant they call 'Chuwar', which acts as the primary fermenting agent.

Deori Community: Chuchra or Suze

This starter is used for making Sujen, the Deori community's sacred rice beer. The starter is a rice based cake infused with the juice or crushed leaves of the 'Chuchra' creeper and other local herbs. The Deori are known for their highly specialized and potent starters, which have strong enzymatic activity.

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Part 2: Fermented Foods Without Complex Starter Cakes

Many fermented foods in Assam are made using simpler methods. These include spontaneous fermentation (where microbes present on the raw ingredients do the work), back-slopping (using a small amount of a previous successful batch to start a new one), or the use of a single alkaline agent like plant ash.

Fermented Bamboo Shoot: Kharisa

This product is popular among many tribes. No external starter is used. Young bamboo shoots are sliced and packed tightly in a sealed container. The fermentation is driven spontaneously by lactic acid bacteria naturally present on the bamboo surface. This process preserves the shoots and gives them a characteristic sour flavor.

Fermented Souring Agent from Colocasia: Pani Tenga

This sour liquid is made by fermenting the stems of the Colocasia esculenta plant. The mechanism can vary. In many households, the fermentation happens spontaneously using the plant's native microbes. In others, a small amount of acidic liquid from a previous batch is used as an inoculum (back-slopping) to ensure consistency. It is used by Bodo, Ahom, and Mising communities.

Fermented Mustard Seeds: Chukapura or Chakapura

This product is made by grinding dry mustard seeds and mixing them with water and the juice or pulp of a sour fruit, such as Thekera (Garcinia pedunculata) or elephant apple. The enzymes and acids from the fruit initiate the breakdown of the mustard, after which natural fermentation continues. It is commonly made by Mishing, Deori, and Sonowal communities.

Fermented Rice Paste: Onthap Bwrwi

This is a fermented rice paste. Cooked rice is mixed with a small amount of a previous fermented batch (the mother culture) and wrapped in banana leaves. The fermentation is driven by lactic acid bacteria and yeasts retained from the old batch. This paste is a staple for the Bodo and Rabha communities.

Fermented Soybean: Saji or Bari

This is a critically important probiotic food missing from many lists. Soybeans are boiled, drained, and wrapped in banana leaves or placed in a bamboo basket to ferment spontaneously for two to three days. The dominant microbe is Bacillus subtilis, which produces a sticky, stringy texture and a strong ammonia like odor. It is a true probiotic and is widely consumed across the Bodo, Karbi, Dimasa, and Rabha communities. It is often eaten with herbs and spices.

Fermented Dried Fish or Shrimp Paste: Bastar or Mairing

This product is made by crushing small fish or shrimp and mixing them with the ash or charred stem of specific plants, such as plantain stem. The mixture is then dried in the sun. The alkaline ash creates a selective environment that favors specific bacteria for a spontaneous fermentation. It is made by Tiwa, Karbi, and Dimasa communities.

Fermented Fish in Alkaline Paste: Paani Prithoni

This is a wet, fermented fish preparation. The "starter" is an alkaline ash, called Khar, made from burning the dried stems of Musa balbisiana (Bhim Kol) and Colocasia. This ash is mixed with the fish to create a highly alkaline environment that drives an enzymatic and microbial fermentation. It is traditionally made by the Mising and Ahom communities. Note that similar products may be called by different names in other villages.

Fermented Fish Paste: Ngari or Hah Chutip

This product is different from Paani Prithoni. It is a drier, salt fermented fish paste, similar to the Ngari of Manipur. Small whole fish are packed with salt and fermented anaerobically for months. It is used as a flavoring agent in Ahom and other Tai influenced Assamese cuisines.

Fermented Mustard Paste with Alkaline Ash: Kharoli

This is a fermented mustard paste. A small amount of a previous batch of Kharoli is mixed with freshly ground mustard and dried Khar (alkaline ash from sun dried banana stem and peel). The Khar does not just act as a starter but also chemically hydrolyzes the mustard oil, releasing compounds that select for specific, desirable lactic acid bacteria. This selection mechanism is unique to this fermentation. It is made by Ahom, Sonowal, and Deori communities.

Tai Phake Fermented Fish with Rice: Peron Namsing and Namsing

The Tai Phake community makes distinct fermented fish products. Namsing is a fermented mixture of rice and fish with herbs, resulting in a semi solid, salty sour paste. A related product, Peron Namsing, incorporates roasted rice powder, adding a smoky flavor. These are different from the fish pastes of other Assamese tribes.

A Note on Probiotic Evidence

The probiotic status of many of these foods is inferred from centuries of traditional use and known microbial science. While the presence of lactic acid bacteria and Bacillus species has been confirmed for some items like Saji (fermented soybean) and Kharoli, many others await detailed molecular validation. However, their role in traditional diets and food preservation is undisputed. Also, the non Saccharomyces yeasts found in many rice beer starters, such as Pichia and Hanseniaspora, contribute significantly to flavor complexity beyond simple alcohol production.