The cold herbal tea Paraguayans drink is called tereré. It’s made from yerba mate leaves steeped in cold water, often with ice and a mix of fresh medicinal herbs. Tereré is so central to Paraguayan identity that UNESCO inscribed it on the Representative List of the Intangible Cultural Heritage of Humanity in 2020, and the country celebrates National Tereré Day every last Saturday in February.
How Tereré Is Made
Tereré starts with processed, minced leaves and stems of the yerba mate plant. These go into a cup called a guampa, and cold water is poured over them from a separate pitcher or thermos. Ice is common, especially in Paraguay’s subtropical heat. The goal is to make the drink as cold as possible.
What sets tereré apart from simply drinking iced tea is the addition of fresh herbs known locally as “yuyos” or “pohã ñana” (Guaraní for medicinal herbs). These are placed directly in the cold water pitcher and left to steep for several minutes before being poured over the yerba mate. Paraguayans select specific herbs based on what their body needs that day: cooling plants for hot weather, digestive herbs after a heavy meal, or calming ones for stress. This folk medicine tradition is deeply rooted in Guaraní ancestral knowledge and remains a living, daily practice rather than a historical curiosity.
How Tereré Differs From Hot Mate
Hot mate and cold tereré both use yerba mate as their base, but the experience is quite different. Hot mate is brewed at 140 to 170°F, which pulls out flavor compounds rapidly and produces a bold, strong, sometimes bitter drink. Tereré, brewed with cold or ice water, extracts those same compounds much more slowly. The result is softer, milder, and more refreshing.
Interestingly, despite the gentler flavor, tereré actually delivers more caffeine per volume. Research published in the journal Nutrients found that a 30-second cold-water infusion produced about 35.8 mg of caffeine per 100 mL, compared to 13.7 to 26.4 mg per 100 mL for a hot infusion at the same steeping time. A full cup of yerba mate tea (about 150 mL) contains roughly 80 mg of caffeine, comparable to a cup of coffee. The yerba mate leaves used for tereré tend to be Paraguayan brands with a specific cut suited for cold brewing.
Nutritional Profile
Yerba mate is rich in polyphenols, a class of plant compounds that act as antioxidants. The dominant one is chlorogenic acid, the same compound found in coffee, along with caffeic acid and several flavonoids including rutin and quercetin. The dried leaves also contain about 22 mg of vitamin C per 100 grams, plus meaningful amounts of B vitamins (B1, B2, and B6) and traces of vitamins A and E.
One practical question people have is whether tereré hydrates as well as plain water, given its caffeine content. A study on street runners found that tereré maintained hydration just as well as a decaffeinated version of the same drink. A separate study on judo athletes showed no difference in body mass or water content between tereré drinkers and water drinkers after a 90-minute training session. The researchers concluded that the volume of water in the drink, not the caffeine, was the primary factor in hydration. That makes tereré a viable option for staying hydrated, especially in hot climates.
The Equipment
Tereré is traditionally sipped through a bombilla, a metal straw with a filtered end that keeps the yerba mate leaves out of your mouth. Bombillas come in stainless steel, silver, aluminum, and even bamboo. Bamboo is particularly popular for tereré because it doesn’t conduct cold the way metal does, keeping the experience comfortable in your hand and on your lips.
The cup, called a guampa, can be made from cattle horn, wood (palo santo and carob are common), or metal. Horn guampas have a rustic look and are a traditional symbol of strength, though they can deform under high heat, which isn’t a concern for cold tereré. Wooden guampas add a subtle flavor and aroma to the drink but need regular oiling. Metal versions are the easiest to maintain and the most durable.
The Social Ritual
Tereré is rarely a solo activity. It’s shared in a round, passed from person to person, and the ritual has specific social rules. One person serves as the cebador, the host who prepares the drink, controls the pace, and makes sure every pour tastes right. The cebador always takes the first sip. This isn’t a privilege; it’s a courtesy, a way of testing the quality before passing the cup to guests.
The guampa circulates around the group, each person drinking the full contents before handing it back to the cebador for a refill. If you want to keep drinking, you simply return the cup without a word. When you’ve had enough, you say “gracias” as you hand it back. In yerba mate culture, saying thank you is the polite signal that you’re done. Saying it too early, before you’re actually finished, can accidentally end your turn in the round.
This communal rhythm turns an afternoon drink into a social anchor. Paraguayans share tereré during work breaks, at family gatherings, and on sidewalks with friends. The UNESCO inscription recognized not just the drink itself but this entire web of knowledge, preparation, and social connection as a living cultural tradition rooted in Guaraní heritage.