Cauim: The Ancient Tupi-Guarani Fermented Manioc Beer of Brazil

In 1557, a German sailor named Hans Staden who had spent two years as a captive of the Tupinamba people on the coast of what is now São Paulo state sat down to document everything he had observed about their way of life. He described the women chewing cooked manioc root until it was thoroughly macerated with saliva, spitting it into large clay vessels, adding water, and leaving it to ferment for several days. The resulting drink — which the Tupinamba called cauim — was consumed at ceremonies, distributed at community gatherings, and drunk in quantities sufficient to mark celebrations as distinct from ordinary days. Staden, a Lutheran from Hesse, found the production method repulsive but the drink itself impossible to avoid: it was everywhere, central to everything, and refusing it was a social impossibility.

Fifty years later, French Protestant minister Jean de Léry — whose 1578 account Histoire d’un voyage fait en la terre du Brésil is one of the earliest sustained ethnographic documents on Brazilian indigenous culture — provided a similar account, noting with his Calvinist eye for precision that the chewing was performed by young women with healthy teeth because their saliva was considered to provide the necessary “ferment” that transformed starch into spirit. He was, without knowing it, describing salivary amylase: the enzyme in human saliva that breaks down starch into maltose and glucose, the same enzymatic mechanism used in Andean chicha masticada, Oaxacan tejate, and the ancient Egyptian bouza’s mold component — all independent discoveries of the same biochemical principle across multiple continents.

What Is Cauim?

Cauim (pronounced roughly kow-EEM, with the stress on the final syllable) is a traditional fermented beverage produced from manioc (cassava, Manihot esculenta), maize, or occasionally sweet potato by indigenous peoples of Brazil, particularly the Tupi-Guarani language family but extending to numerous other Amazonian and Atlantic coastal groups. It is mildly alcoholic — typically 2–5% ABV — slightly cloudy, and tasting of fermented starch with a gentle sour note from lactic acid bacteria that colonize the fermentation vessel.

The word cauim derives from the Tupi-Guarani root ca’u or ka’uy, which appears in various forms across dozens of indigenous languages of South America, always designating a fermented grain or root beverage. This linguistic distribution is itself evidence of ancient trade and cultural exchange networks among pre-Columbian South American peoples: the drink and its name spread together across thousands of kilometers of diverse terrain.

Unlike corn chicha (which uses germination/malting or the masticating method) or manioc drinks like masato (which primarily uses salivary amylase or natural LAB), cauim traditionally relied specifically on the masticating method — women chewing the cooked manioc root and adding their saliva as the primary amylase source. This method has been documented across dozens of Brazilian indigenous groups and continues in several Amazonian communities, where it marks celebrations, ceremonies, and the labor-exchange gatherings that organize community agricultural work.

The Science of Masticatory Fermentation

Salivary amylase (alpha-amylase, encoded by the AMY1A gene) is present in human saliva at concentrations of 60–300 mg/L and is capable of breaking down amylose and amylopectin — the two components of starch — into shorter-chain dextrins, maltose, and glucose. When cooked, gelatinized starch is chewed thoroughly by individuals whose salivary amylase concentration is adequate, the resulting macerated material, when added to water and allowed to ferment, provides sufficient fermentable sugars to support active yeast and lactic acid bacteria fermentation.

Humans who consume high-starch diets have higher AMY1A gene copy numbers and correspondingly higher salivary amylase concentrations than those who historically consumed low-starch diets — a documented example of rapid human genetic adaptation to agricultural diet. Research by Perry et al. published in Nature Genetics (2007) demonstrated this copy number variation and its relationship to salivary amylase production, inadvertently providing a scientific basis for why certain populations might produce more effective masticatory chicha starters than others: their genetic history of starch consumption has equipped them with more amylase.

The wild yeast and lactic acid bacteria that colonize the fermentation vessel do the subsequent work: Saccharomyces cerevisiae and Schizosaccharomyces pombe have been identified in Amazonian fermented beverages, alongside lactic acid bacteria including Lactobacillus plantarum, L. fermentum, and Pediococcus acidilactici. This consortium is qualitatively similar to other traditional fermented grain beverages worldwide, suggesting that the global microbial community available for spontaneous fermentation is more consistent than the widely varying production methods employed to access it.

Cauim in Tupi-Guarani Culture

For the Tupinamba, Tupinikin, Guarani, and related groups that occupied the Atlantic coast and inland regions of what is now Brazil before and during European contact, cauim was not merely a drink but a social institution. The cauinagem — cauim-drinking ceremony — was one of the central events in Tupi-Guarani community life, organized around specific ritual purposes: warfare preparation (warriors drank cauim before raids and battles), mourning the dead, celebrating a successful hunt, and marking the incorporation of new community members.

The production of cauim was exclusively women’s work, and the labor involved was substantial: preparing, cooking, masticating, and monitoring large quantities of cauim for a community ceremony could occupy women for days before the event. This labor was a form of community contribution equivalent to the agricultural labor men contributed in clearing and planting. The division was not merely practical but symbolic: the women who made the cauim were understood to be incorporating part of themselves — literally their saliva, their biological chemistry — into the drink that would sustain and bind the community during its most important moments.

Portuguese missionaries in the 16th and 17th centuries, dismayed by both the masticating method and the communal intoxication it produced, attempted systematically to suppress cauim production as part of the broader project of converting coastal Tupi peoples to Christianity. Their success was partial and temporary. Cauim retreated inland as Tupi communities were displaced westward and southward; it persisted among Amazonian groups who maintained sufficient distance from colonial settlements to continue traditional practices.

Making Cauim at Home: Adapted Modern Method

The traditional masticating method for cauim is impractical for home production at meaningful scale and is not typically undertaken by those outside the cultural tradition in which it has meaning. Modern adaptations use malted barley, wheat malt, or commercial amylase enzymes as substitutes for salivary amylase — enzymatically equivalent (both produce the same sugar substrates) and practically more accessible.

Ingredients

• 500g sweet cassava/manioc (not bitter cassava — must be the sweet variety), peeled and diced
• OR 400g cassava flour (tapioca flour) as an easier alternative
• 100g malted barley flour (provides amylase to convert cassava starch to fermentable sugars)
• 1 liter warm water
• Optional: a tablespoon of sourdough starter or a pinch of active dry yeast to assist fermentation

Method (Diced Cassava Version)

Step 1: Cook the cassava. Peel sweet cassava carefully (both outer bark and pinkish inner skin), removing any brown fibers. Dice into 2–3cm pieces. Boil in plenty of water for 25–35 minutes until completely soft and slightly translucent throughout. Drain and mash while hot, removing any fibrous cores.

Step 2: Cool and mix with malt. Allow the mashed cassava to cool to 60°C — warm but not burning hot. Add the malted barley flour and mix thoroughly. The malt’s amylase enzymes work optimally at 60–65°C (saccharification temperature). Hold the mixture at approximately 60°C for 30 minutes if possible (use a thermos, a low oven, or a warm water bath) to maximize starch conversion. A sweet smell and slightly sticky, liquifying texture indicates successful conversion.

Step 3: Ferment. Add the warm water and optional starter to the cassava-malt mash. Transfer to a clean fermentation vessel. Cover loosely with cloth. Keep at 25–30°C. Fermentation should begin within 12–24 hours. Traditional cauim is consumed at 48–72 hours, when it is still slightly sweet and 2–4% ABV, with a mild lactic sourness. Longer fermentation produces a more strongly alcoholic, more sour drink.

Step 4: Strain and serve. Strain through a coarse cloth to remove mash solids. Serve the liquid in cups — traditionally gourd cups. Some people add chili or spices at serving. Drink fresh; cauim acidifies rapidly after straining.

Cassava Flour Method (Faster)

Combine 400g cassava flour with 100g malted barley flour. Add 1.2 liters of warm water (65°C) and stir to a smooth slurry. Hold warm for 30 minutes, then cool to 30°C, add starter, and ferment 48–72 hours as above. Strain and serve. This method sacrifices some flavor complexity but is considerably more accessible.

Cauim and Brazilian Indigenous Rights

Cauim production today is an act of cultural persistence as much as a brewing practice. Several Amazonian indigenous groups — including the Tenetehara, the Munduruku, and some Xingu peoples — continue to produce cauim using traditional methods for ceremonial purposes, as a deliberate assertion of cultural continuity in contexts of significant land rights pressure, deforestation, and cultural assimilation policy. Ethnobotanical documentation projects by Brazilian researchers in collaboration with indigenous communities have been collecting and preserving knowledge of cauim production, ingredients, and ceremony in recognition that this knowledge is under threat from demographic and environmental change.

Nutritional and Probiotic Profile

Cauim fermented for 48–72 hours contains viable lactic acid bacteria and wild yeasts. The fermentation process significantly reduces the cyanogenic glycoside content of manioc — a critical food safety benefit when dealing with cassava, whose bitter varieties contain high levels of hydrogen cyanide precursors. Both the initial cooking and the lactic acid fermentation break down these compounds. Research on cassava fermentation products consistently shows that properly fermented cassava products are safe and nutritious, with phytic acid reduction, improved protein digestibility, and substantial B-vitamin synthesis by the fermenting microorganisms.

Final Thoughts

Cauim is the fermented drink at which all roads through Brazilian food history converge: the manioc of Amazonian agriculture, the salivary chemistry of human biology turned into a fermentation technology, the social rituals of communities whose descendants are still making their case for survival in the Amazon basin today. It is a drink that asks something of you — not just the patience of fermentation but the willingness to encounter a production tradition that is genuinely other, genuinely ancient, and genuinely alive. The modern adaptation offered here is an approximation. The real thing lives in communities that have not stopped making it, in ceramic vessels that have been used for this purpose for hundreds of years, in the hands of women whose knowledge of cauim is knowledge about who their people are.