Before brewing Yerba Mate in Your Gourd it needs to be cured. There are two methods for curing depending on whether you are brewing the regular kind of Mate (Amargo) or the Sweet version (Mate Dulce).

To cure your gourd for Amargo rinse the gourd with warm water. Fill the gourd to the rim with used or fresh Mate leaf, and then pour warm water over the Mate leaf to the top of the Gourd. Let the Gourd sit for 24 hours.
After 24 hours empty the Gourd completely and allow to dry. You can repeat this process again if you wish.
For Mate Dulce, rinse the Gourd with warm water, then pour some sugar into the Gourd and shake it around, so that the walls are coated with a layer of sugar. Then place an ember of gently burning charcoal into the Gourd and shake around so that the sugar forms a caramel layer on the walls of the Gourd. This can be repeated between servings of Mate Dulce to boost the flavour of the beverage.