Mate is the infusion beverage prepared from the dried leaves and twigs of yerba mate (Ilex paraguariensis), traditional in Argentina, Uruguay, Paraguay and southern Brazil, where it is drunk from a gourd (cuia) through a filtered straw (bomba), often shared socially. The caffeine-, theobromine- and polyphenol-containing infusion is stimulating with a characteristic bitter, vegetal flavour, consumed hot (chimarrão) or cold (tereré). Commercial mate must be harvested, blanched (sapeco), dried and milled hygienically; smoke-drying can introduce polycyclic aromatic hydrocarbons (PAHs), so reputable producers control drying and test for PAHs, pesticides and microbial contaminants, with labelling following herbal-infusion regulations.