What is roasted mate?

From green to brown, yerba mate goes through roasting! This step transforms its aroma, color, and even part of its composition. But how do you roast a mate leaf? Is it the same as coffee? And in which countries is this version the star of the cup? We’ll explain it all, without getting too smoky about it. 🌿

🌱 First, where does mate come from?

Yerba mate comes from the leaves of Ilex paraguariensis, a tree native to South America. Long before becoming a trendy drink, it was consumed by the region’s indigenous peoples, particularly the Guaranis. The tradition then spread and took root in several South American countries.

Today, mate comes in several styles: dried and ground leaves for the traditional ritual, cold brew, or even roasted mate, whose roasted notes can be reminiscent of roasted tea or even coffee.

One important detail: traditional mate is already heated during production. But this initial heating, called sapeco, is mainly used to stop enzyme activity and prepare the leaves for drying. Roasted mate, on the other hand, undergoes additional heating intended to develop its aromas. So it’s not quite the same step!

🔥 How does roasting work?

Imagine mate leaves changing from their green, plant-like state to a browner color, with a rounder, more indulgent aroma. This change is brought about by heat.

1. The leaves are harvested

The leaves and small branches are harvested and then transported to the processing facility. They are not ready to be brewed as they are: they must be treated and dried.

2. The plant is heated to prepare it

An initial quick heating, the sapeco, helps inactivate the enzymes responsible for oxidation. Drying follows, and methods vary among producers: hot air and smoke can play a role in the final aromatic profile.

3. It is roasted to develop the aromas

During roasting, heat causes chemical changes in the leaves. Aromatic compounds are formed, while some naturally occurring compounds decrease or are transformed. The duration and intensity of the heating influence the result: just like with coffee, a few adjustments can change the character of the drink.

4. The mate is prepared for its future cup

After heat treatment, the mate is prepared according to the desired product: it can be ground, sifted, blended, and then packaged. Depending on the methods and markets, a resting or maturation period may also contribute to its final profile.

Key takeaway: there is no single universal roasting recipe. Methods vary depending on the producers and the style of mate desired.

👃 And in terms of taste, what changes?

That’s where the magic happens! Or rather, the magic of chemistry. 🧪

Unroasted mate is often associated with a vegetal, herbal profile that can sometimes be quite bitter. The roasted version tends to offer warmer, more roasted notes.

Depending on the degree of roasting, you may find:

• Roasted notes, reminiscent of toasted cereals or nuts.

• Woody and smoky aromas, particularly when smoke is used in the process.

• Rounder, sometimes caramelized touches, linked to the formation of new aromatic compounds.

• Less vegetal freshness: some compounds associated with green and floral notes decrease during heating.

A study published in 2021 in the journal Molecules describes, among other things, changes in aromatic compounds between green mate and roasted mate. Compounds such as furfural and methylfurfural may contribute to the sweet and smoky notes of the roasted version.

And no, roasted mate is not simply coffee disguised as a South American plant: its profile remains that of mate, with its own compounds and distinctive character.

🧪 Does roasting also change its composition?

Yes. Heat does not only transform the aroma: it also modifies certain compounds present in the leaves.

A study published in 2022 in ACS Food Science & Technology found that roasting reduced the chlorogenic acid content of mate under the conditions studied. It also showed the formation of melanoidins, brown compounds resulting from heat-related chemical reactions.

Melanoidins contribute to the color and may contribute to the antioxidant activity measured in the laboratory. However, this does not mean that roasted mate is better for your health than unroasted mate. The composition changes, but this alone cannot be used to conclude that it offers greater health benefits to humans.

In short: roasting changes the profile of mate; it does not automatically make it healthier or less healthy.

🌎 Where is roasted mate drunk?

Mate is deeply rooted in several South American cultures, but not everyone prepares it the same way.

🇧🇷 In Brazil: a special place for roasted mate

Brazil has a long tradition of mate consumption, particularly in the South. You’ll find chá-mate, an infusion made with roasted mate that can be drunk hot or cold (we recommend a very cold matesol!). Alongside this version, chimarrão is generally prepared with finely ground green mate and hot water.

🧉 So, green mate or roasted mate?

It mostly comes down to taste and preference.

• Do you like vegetal, herbal, and bold flavors? You might enjoy green mate.

• Do you prefer rounder, roasted, and slightly smoky notes? Try roasted mate.

• Can’t decide? The best test is to try both, ideally prepared in a comparable way.

At Matesol, we love mate in all its forms: understanding its origins, transformations, and flavors is also a way to appreciate it even more. And in a mate drink, the final profile depends not only on the roasting but also on the brewing, other ingredients, and the balance of flavors.

The next time you notice roasted notes in your mate, you’ll know they didn’t get there by chance: behind that little toasted flavor lies a wealth of expertise. 🔥🌿

🔎 Scientific sources and references

1. Yerba Mate—A Long but Current History (2021), Molecules. A review of the history, processing, and aromatic compounds of mate. https://pmc.ncbi.nlm.nih.gov/articles/PMC8622869/

2. Drinking Coffee, Mate, and Very Hot Beverages, International Agency for Research on Cancer (IARC), IARC Monographs, volume 116. Information on the production and consumption of mate. https://publications.iarc.who.int/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Drinking-Coffee-Mate-And-Very-Hot-Beverages-2018

3. Mate (Ilex paraguariensis) Toasting Causes Chlorogenic Acids to Degrade and Incorporate into the Backbone of Melanoidins, Contributing to Their Antioxidant Activity (2022), ACS Food Science & Technology. A study on the effects of roasting on chlorogenic acids and melanoidins. https://doi.org/10.1021/acsfoodscitech.2c00054