Men have developed different techniques to process Yerba Mate.
Physical efforts have decreased but quality, flavor and aroma had remained the same for over 200 years.
The harvest season extends from March to October.
As subtropical or tropical plant, the Illex Paraguariensis (Yerba Mate) requires high temperatures, high humidity in the soil and environment conditions. The plant needs about 1,500 mm of annual rainfall, with frequent falls in the months of September to February. The red earth of Misiones, loaded with iron oxide, known as laterite, is considered the best place for the development of Yerba Mate. Generally the further north the plant is harvested (south of Brazil), the stronger the taste.
Every detail after the harvest is very important because you have to process the Yerba Mate leaves no longer than 24 hours after they have been cut from the tree.
The drying process has two steps, "sapecado" and "secado". Sapecado is dehydrating the leaves. This process is achieved through fire. It only takes 20 to 30 seconds. This is done to stop the natural oxidation and fermentation process of the plant. If the heat that is used is excessive, the leaves will have a yellow color and would affect the final taste. The proper heat is very important. In this process the leaves lose 20% of their weight.
The Secado is the second step in the drying process. The Guarani Indians used two systems to do the secado.
One was called "carijó" and the other was "barbacuá". In carijó the heat of the fire goes directly to the leaves.
In barbacuá the heat reaches the leaves through an indirect way through a tunnel under the earth.
This is a smoking type process. Today they are dried both directly and indirectly using gas or wood and modern equipment.
The next process is the "canchado". This is the process where the leaves are roughly milled right alter the secado. Afterwards they are put in jute sacks (natural fiber) which are marked with the date and the origin location. This type of yerba is called "CANCHADA". This is the name yerba mate is given when it´s grossly crushed right alter the drying process It still needs to be processed in the mill. If you ever try to brew mate with this type of yerba (you´ll have to travel to where yerba mate is produced first as this type of yerba is not sold to the public) you will notice it has a very weak flavor as it has no powder (what indeed are finely ground leaves) which is the main ingredient to be dissolved in water.
The next process is called "BENEFICIO" where the yerba mate is left to age for a minimum of six months. This is VERY IMPORTANT in order to get a top quality yerba. Organic and small farmers producers usually let this process last more than a year, sometimes even two.
The final step is the milling. Through a sifting process done by specialised machinery the aged yerba is separated from its content of twigs, leaves and sticks or stems. The yerba is then blended in the proper proportions each brand has. Some may have more sticks, leaves or powder than others. Finding the "right" yerba for you will take some time.
There are two distinct kinds of flavors in yerba mate according to the drying process : smoked (sometimes also called "barbacuá") & unsmoked.
On the other hand, we have two types of yerba mate according to its grinding; with or without stems or sticks. Most brands use the variety "with sticks" (con palo). Few brands have the "w/o sticks" (sin palo) version available.
So, basically there are six commercial types of yerba mate: Elaborada con Palo (w/stems) - Elaborada sin Palo o Despalada (w/o stems) - Barbacuá (Smoked) - Tostada (Roasted) - Flavored & Mixed with Herbs.
ELABORADA CON PALO (with stems) : Is the yerba mate that contains no less than 65% dehydrated ground leaves and no more than 35% of stems. Generally they are mild because of the big percentage of stems or sticks.
DESPALILLADA, DESPALADA o SIN PALO (without stems) : It contains no less than 90% of finely dehydrated leaves and no more than 10% of stems. This type of yerba (very popular in Brazil) is stronger due to their larger quantity of leaves and fewer amount of stems. There is no such thing as a yerba COMPLETELY 100% WITHOUT stems even though the package says so. There will always be a very small amount that is impossible to be removed during the processing.
SMOKED (BARBACUÁ ) : Is the yerba that´s dried and smoked over wood heat. The heat reaches the leaves through an indirect way through a tunnel under the earth. This is the oldest drying process. Nowadays it´s done by small farmers or cooperatives only, like "Titrayju". These yerbas have a strong and delicious aroma and a woody taste, Big companies buy the production of these small farmers for their "Barbacuá" brands. Sometimes you may find some yerbas that claim to be "UNSMOKED". By definition all yerbas that have not been dried using the barbacuá system are unsmoked.
TOSTADA (ROASTED) : When the yerba leaves are roasted they generally have a sweeter flavor and a kind of a "chocolate" after taste. If you don´t like the bitterness of yerba mate you should try this type.
FLAVORED YERBA MATE : Yerba mate with different flavors microencapsulated into the tea which sometimes also includes bits of the fruit itself. The flavors are essential oils derived from the fruits.
MIXED WITH HERBS : Yerba mate with different natural herbs mixed into it
Undoubtedly, ORGANIC YERBA MATE is the highest quality option. It has no agrotoxins or pesticides. To control the grass that is not good for the plants, sheep are sometimes used to graze. Even though the prices for organic yerba are higher, most people prefer the organic type because of the health properties and also because it is better for the environment. The packaging material that is used is organic in itself as the paper that is used is recycled and biodegradable. The ink is water based. Organic yerbas are not as easily found as regular teas in Argentina.
This is mainly because they are sold in specialty and health food stores. The producers of organic yerba mate are very small companies. Normally the aging process for the organic yerbas are longer than the regular ones therefore the flavor and aroma are better. It also makes the yerba mate taste less acidic.
INSTANT YERBA MATE is dehydrated powder, very similar to instant coffee. Not very traditional in Argentina.