Mate is an infusion made with yerba mate leaves (Ilex paraguariensis), a plant native to the basins of the Paraná rivers, Paraguay and the upper course of the Uruguay River. These previously dried, cut and ground plants form yerba mate, which has a bitter taste due to the tannins in its leaves. For this reason, there are those who like to sweeten the mate a little with sugar, stevia or a non-caloric sweetener. The foam that is generated when "priming" is due to the glycosides that yerba mate contains.