1800-1000 BCE
The Olmec produced and consumed cacao products at the beginning of the Early Preclassic period

A study done by Terry G. Powis et al., which used sensitive laboratory techniques to determine the presence or absence of cacao residues from a wide array of early Olmec pottery, confirmed the presence of cacao residue in 27 objects of variable forms, dates, and composition. This supports conclusions by previous researchers that the Olmec were involved in the production and consumption of cacao products at the very beginning of the Early Preclassic period (circa 1800 to 1000 BCE).

Source: Powis, T. G. et al. (2011). Cacao use and the San Lorenzo Olmec. Proc Natl Acad Sci