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Research note 032 — 2026-09-04

Drinking Mate 'Bitter, As It Is'

Mate is a beverage widely drunk in South America, and the way of drinking it without added sugar is called amargo (bitter). This much, multiple sources agree on. But summing it up in one sentence — "South America drinks mate bitter" — makes for a coarser story than the material gathered here actually records. Argentina defines mate as the national infusion by law; a survey in Uruguay finds over nine in ten university students say they drink it unsweetened; and an ethnography from Chile notes that even within the same country, its meaning differs by region. This note lays out how the sources diverge from one another within the single phrase "bitter, as is."

What this page establishes

• In Argentina, it has been confirmed, in the exact wording of the statute, that a law designates mate as the "national infusion."
• In a survey of 470 university students in Uruguay, 94.7% were confirmed to have chosen unsweetened amargo.
• An ethnographic study in Chile shows that, even within the same country, mate is described as carrying different meanings in the south and in Santiago.
• Which bitterness receptor the mate infusion itself is perceived as bitter through has not yet been measured.

What Mate Is

Mate tea is recorded as most commonly prepared by pouring water at 65-95°C over tea made from the leaves (and twigs) of Ilex paraguariensis, roasted, dried, and aged.

The infusion contains purine alkaloids such as caffeine, theobromine, and theophylline.

On the sensory-research side too, mate tea infusion has been treated as one member of the bitter-beverage category. In a multiple-sip time-intensity study with an Argentine consumer panel, mate tea infusion was used as a commercial bitter product alongside PROP solution, coffee, and grapefruit juice, and a cumulative effect was confirmed in which the maximum intensity of bitterness increased with each sip.

When It Is Called the National Infusion

Mate tea has, for centuries, been an object of social drinking among indigenous peoples, and the drinking custom itself is described as part of the culture.

In Argentina, this beverage is written into the text of the law itself. Article 2 of Ley 26.871 defines mate as "the infusion prepared based on the food product yerba mate, which, placed in a container and moistened with hot water, is drunk through a bombilla (a metal straw)."

The same law was enacted on July 3, 2013, and designates mate as the "Infusión Nacional" (National Infusion), providing for the promotion of its consumption and customs at official national cultural, social, and sporting events. This, however, is the wording of the statute; it does not record the actual state of compliance or how widely it has taken hold in society.

Sweet, Bitter, Cold: The Ways of Preparing It Diverge

Argentine sources set 3 types side by side: mate amargo (unsweetened), mate dulce (sweetened), and cold tereré, traditional in summer. They also touch on the spread of new ways of drinking aimed at younger people and sports enthusiasts, so amargo is not described as the only type.

Consumption itself is large. Mate is present in over 90% of households within Argentina, and annual per-capita consumption is reported, depending on the source, as about 6.4kg, or as increasing from 5.90kg to 6.17kg. A total consumption figure of 316.1 million kg (275.8 million kg domestic, 40.3 million kg exported) is also reported, but no source or survey method is stated, and the figures vary by year.

Cross a Border, and the Ratios Change

An ethnographic study in Chile (Cayul & Pessoa, 2020), based on 12 in-depth interviews (June-October 2019, ages 20-90, Santiago/Osorno/Castro/rural areas), contrasts the southern Los Lagos region, where it is described as a shared, passed-around drink grounded in an aesthetic of co-presence, with Santiago, where it has become more technologized and individualized, becoming one element of a distinction that signals "good taste among the upper-middle class." The preference for unsweetened mate in Santiago is described as linked to a cult of health and to distinction, while in the south, not adding sugar or herbs is recorded as the norm for "correct" mate amargo, though those who prefer sweetness are also recorded as adjusting it with sweeteners. It is worth noting that the word amargo itself is also used idiomatically to mean unsweetened.

In a survey of 207 people in Paraguay's Central Department (Figueroa et al., 2024), respondents reported consuming tereré (81.6%), mate (the hot preparation, 69.1%), and mate cocido (boiled, 80.2%), with the most common combination being the use of "mate+tereré+cocido" together (43.96%). The most preferred type was yerba blended with medicinal herbs, at an average of 1.5 liters per day. The same source also states that mate is distinguished between mate dulce, with sugar added, and mate cimarrón (amargo), drunk bitter as it is. It is, however, a non-probability sample, and it is not nationally representative.

In a cross-sectional survey of 649 university students in Uruguay (Araújo, Barreto, Beltramelli, 2021), among the 470 students who actually drink mate, 94.7% reported amargo (unsweetened), 4.0% both amargo and dulce, and 1.3% dulce (sweetened). The difference by region of origin (interior 93.6% vs. Montevideo 97.5%) was not statistically significant (p=0.142).

Drinking Alone, or Drinking With Someone

The same Uruguayan survey asked not only how mate is prepared but also who it is drunk with. While 85.3% of the students who drink mate reported drinking it "with companions," a before-and-after comparison across the pandemic found that the share drinking "alone" rose from 0.7% to 14.7%, while the share drinking "with companions" fell from 99.3% to 85.3% (p<0.001). This is a single-timepoint retrospective self-report, not an experiment that isolates the pandemic's effect alone.

In the same survey's background description, mate is treated as one of the customs representing Uruguay's food culture, and is positioned as one of the most frequent habits passed down across generations from early childhood.

What is not known

The material gathered so far builds up figures on "with whom, in what preparation, and how much" mate is drunk. But this time, it was not possible to reach a receptor-level explanation of "why the mate infusion itself is perceived as bitter." The receptor research found deals not with a component of mate itself but with monosodium glutamate (MSG): in an experiment using HEK293T cells expressing hTAS2R16, MSG acted as a surmountable antagonist of the bitter-receptor response to salicin and related compounds. This concerns a different substance and a different receptor from the mate infusion or its components, and no human sensory evaluation was carried out. Which receptor mate's own bitterness works through is left here as a question outside the scope of this card.

Honest notes

• The consumption and ratio figures set out here differ from source to source in both survey method and year. Where a range of figures exists even within the same country, it has been left as is.
• The word "amargo" is sometimes used to refer to the unsweetened preparation, and sometimes idiomatically to mean the "correct" way of drinking mate in a given region. Both uses appear within the same material.
• The material from Argentina, Chile, Paraguay, and Uruguay each comes from a different research body and a different sample; it is not one single survey representing South America as a whole.
• This note makes no claim about efficacy or health effects. The receptor-research card, too, does not demonstrate mate's sensory experience.

Frequently asked

Is it normal to drink mate unsweetened (bitter, as is)?

It differs greatly by region. In a survey of university students in Uruguay, 94.7% of the students who actually drink mate reported choosing unsweetened amargo. In a survey in Paraguay's Central Department, on the other hand, tereré, hot mate, and boiled mate cocido are used together, and while a distinction between unsweetened and sweetened is drawn, it does not add up to a single answer. In Chile too, an ethnographic study records that the very reasoning behind choosing unsweetened mate differs between the south and Santiago. No survey in this inventory has confirmed that "drinking it bitter, as is" is one uniform custom.

Why is mate bitter (which component is bitter)?

This has not been directly confirmed. The infusion contains purine alkaloids such as caffeine, theobromine, and theophylline, and their content is described as comparable to coffee, but this is a statement about content, not a description that directly measured which component is the main carrier of mate's bitterness. On the sensory-research side, mate tea infusion has been treated as a beverage in the bitter category alongside PROP solution and coffee, and a cumulative effect in which bitterness strengthens with each sip has been confirmed. This, however, is a confirmation that "mate is treated as a bitter beverage," not an identification of the molecule that carries the bitterness. Which receptor mate's own bitterness works through has not yet been measured.

Related: yerba mate infusion / monosodium glutamate
Related research notes: How Bitterness Gets Institutionalized / Where "Bitter" Becomes a Compliment
Source ledger: the source ledger