Barbacuá mate: a dangerous traditional drying method?

Polycyclic Aromatic Hydrocarbons (PAHs) are chemical substances that form when organic materials, such as wood or coal, burn incompletely. This means that combustion is not complete, resulting in the production of residues in the form of particles and gases.

A well-known example of such a substance is benzo(a)pyrene . This compound has been the subject of numerous scientific studies because it is recognized as dangerous to health. Indeed, several international organizations, including the International Agency for Research on Cancer (IARC), classify it as a carcinogen, meaning it is capable of causing cancer.

In the drying process called barbacuá , used particularly for preparing yerba mate, the hot smoke in contact with the leaves directly deposits these combustion residues. This is how PAHs can end up in the final product.

When preparing yerba mate (with hot water), some of the PAHs ( polycyclic aromatic hydrocarbons) adhering to the leaves can dissolve into the infusion. While the extent of this exposure varies depending on the smoking time, the type of wood, and the distance between the flame and the leaves, it is essential to be aware of this when regularly consuming smoked yerba mate.

Several epidemiological studies conducted in Argentina, Paraguay and Brazil suggest a link between the very frequent consumption of smoked mate (often associated with barbacuá) and an increased risk of certain cancers (mouth, esophagus).

Note : Studies also point to excessively high infusion temperatures as an aggravating factor, but the presence of direct smoke introduces PAHs into the drink and can accentuate these risks.

The World Health Organization (WHO) warns against consuming very hot beverages. Furthermore, various agencies – including the International Agency for Research on Cancer (IARC) – recognize the proven or probable carcinogenicity of PAHs .

Although these substances are controlled for certain smoked products (fish, cured meats), there are no such strict international standards for yerba mate. This lack of clear regulation makes it difficult to guarantee low PAH levels in all barbacuá products.

More and more plantations are replacing or supplementing the traditional barbacuá method with modern processes aimed at avoiding direct contact between yerba mate leaves and wood smoke.

Unlike barbacuá, where the leaves are exposed to the smoke of a wood fire, hot air drying relies on indirect and more precisely regulated heat. Here are the main steps:

1. Loading the sheets
   Freshly harvested yerba mate is placed on a conveyor belt or in rotating drums inside a drying tunnel.
   
   
2. Hot air circulation
   Hot air (from a boiler or gas/electric heat source) is then propelled or drawn into the tunnel, circulating around the leaves.
   
   
3. Precise temperature and humidity control
   The hot air gradually extracts moisture from the leaves, without producing smoke in direct contact with the mate leaves.
   Regulation helps to avoid excessively rapid drying, which could alter the aromas or the quality of the leaves.

Combustion, when it occurs, takes place in a separate compartment, and the resulting smoke is usually eliminated or diverted before reaching the leaves.

This method has several advantages: it eliminates the presence of PAHs thanks to the absence of direct contact with smoke, while allowing for finer control of humidity levels and temperature.

This is precisely the drying technique that our producer uses for drying their organic mate.

Reduction of PAHs to near-zero levels

• Elimination of risks associated with contact with wood smoke.
• Compliance with stricter health standards in Europe and elsewhere.

Preserving the properties of yerba mate

• Better preservation of nutrients (polyphenols, antioxidants).
• Maintaining a purer and fresher taste, without an overly pronounced smoky aroma.

Precise quality control

• Precise humidity control, ensuring optimal shelf life .
• Less variation between production batches.

Reduced environmental impact

• Less pollution from burning wood.
• Some modern facilities use renewable energy to heat the air.