Dark tea goes through a primary processing similar to that of Green tea.  It then undergos a secondary processing of microbial fermentation and oxidation. Fermentation is the chemical breakdown of the tea leaf by bacteria, yeast, or microorganisms. Dark tea undergoes an aging process in which bacteria reacts with the leaves, changing the chemistry, flavor, aroma, and appearance of the leaf.

Dark tea can be light to full bodied, a lingering finish, and a flavor profile that ranges from sweet and floral to woody and earthy. Puerh is a subcategory of Dark Tea.