The Rooibos leaves are green when harvested, and whilst these un-oxidised green rooibos leaves are now available, almost all commercially available Rooibos has been naturally fermented and dried to reach its traditional and familiar deep red colour. After harvesting, the green rooibos leaves are cut, moistened and left in piles to ferment for several hours. This process allows the phenolic compounds in the plant to develop, the leaves are then spread into thin layers and sun-dried.
Rooibos is reported to contain up to 50% more polyphenols and antioxidants than Green Tea and is especially high in two unique polyphenols, including one that is found exclusively in Rooibos called Aspalathin. Antioxidants such as these may protect against the negative effects of free radicals in the body, and Rooibos tea has also been named as a leading source of anti-cancer compounds by the South African Cancer Association.