There are many methods of brewing yerba mate. Traditional ways of preparing the drink in Argentina and Brazil differ from those in Paraguay or in the Middle East. There is simply no one ‘correct’ method, just like there is no one correct way of brewing tea or coffee. Preparing and serving mate in a gourd is most popular but using wooden, ceramic or other vessels is just as good. A bombilla, on the other hand, is absolutely necessary for drinking yerba mate.
The simplest way of preparing yerba mate is as follows:More complicated rituals for brewing yerba mate have been developed to avoid these problems. Below is a description of one of them:
The gourd is filled with yerba up to ½ or ¾ of its capacity. Additional herbs may be added to increase the flavour or the healthy properties of the drink. This is common in Paraguay where people prepare yerba mate as a base for herbal drinks brewed with various herbs supplied by the local herbalists yuyera. The gourd with the appropriate mixture is then covered by hand, turned upside down and shaken for a short while, energetically to start with and then more and more gently. In this upside position the smallest leaves travel towards the hand. The gourd is then carefully turned horizontally, keeping the opening slightly above the level of the base, whilst still slightly shaking the leaves between the walls of the gourd. When the leaves settle on the side wall, the gourd is turned the right way up again trying to ensure that the smallest leaves stay on the top. The whole procedure is meant to ensure that these small particles stay as far away from the bombilla opening as possible. When mate is then drunk, the small leaves will travel toward the bombilla but the bigger leaves and twigs at the bottom of the gourd will act as a filter. They will stop the smallest particles and the dust from entering the bombilla, preventing its clogging and maintain the flavour for the next brewing.
When this stage is completed, the bombilla should be placed inside although some people prefer to pour water over the leaves first and then place the bombilla. With the bombilla inside the gourd, cool water (at room temperature) is gently poured onto the leaves filling the container nearly up to its brim. This is then left to stand to allow the yerba to soak up the water. Once the leaves are wet they have to be gathered together and formed into a mound. This is done by using the bombilla. Dry leaves would make the insertion of the bombilla easier but avoiding disturbing the leaves would be more difficult. At the end the bombilla, with its top opening closed with a thumb, is placed in the empty space at the bottom, carefully so as not to disturb the mound.
If the leaves are dry when the bombilla is placed in the gourd, the leaves have to be treated with cold water (room temperature as above) and left to absorb this water, which takes no more than 2-3 minutes. Using cold water before brewing in warm water is important because it helps maintain the aroma and protects the mate from chemical breakdown and the loss valuable nutrients. Hot water (70–80 °C - 158-176 °F) may now be added. It should be poured carefully over the bombilla and into the cavity in the gourd next to the yerba. The gourd should be nearly full but the very top of the mound should remain dry. Once the warm water has been added, the yerba mate is ready for drinking. Warm water may be added a few times, until the drink loses its flavour and becomes a washed out lavado. When that happens, the yerba mound can be moved from one side of the gourd to the other and the water then poured onto the other side of the mound of leaves. This process, known as reformar o mate revives the mate for further refilling.
Some people add sugar or honey to the drink to make mate dulce - sweet mate. The unsweetened mate is known as mate amargo – bitter mate. It is believed that sweet mate might cause damage to the calabash gourd or the wooden gourd and for this reason a separate vessel is often used to serve it. Dry leaves of stevia may be used to sweeten mate. Stevia, like yerba mate, comes from Paraguay and is a natural sweetener. It contains no sugar and does not affect the gourd. Mate dolce used to be regarded as a drink for women and children only. Nowadays this is no longer the case.
The ceremony of preparing yerba mate is a little bit complex but it does not need to be followed to the letter. Everyone can pick and choose which parts of the process appeal to them.
To prevent clogging up of the bombilla the following should be observed:There is some controversy surrounding the required temperature of the water. Some people use a thermometer to ensure that they use water at between 70 and 80 °C (158-176 °F). Others do not think that such precision is necessary as long the main rule is observed; the rule being that the water must not be at boiling temperature. It is best to choose the temperature that suits the individual drinker. A thermometer may be useful at the beginning when one is learning the process but it is not vital to have one. If the water it too hot, the yerba mate becomes bitter and too strong. If the water is near boiling temperature, then the mate cannot be drunk immediately as it is simply too hot and might burn. Mate prepared at a lower temperature may be drunk very quickly, as soon as it acquires the appropriate strength.
Anyone newly introduced to yerba mate might find the traditional infusion a bit too bitter. It might be best first to buy mild mate (suave mate), place fewer leaves in the gourd (up ¼ - ½ of the container) and maybe even use a sweetener.