What role did wine play at the symposium?

Only wealthy drank wine because they could afford it.

Became a symposium of power, prosperity and privilege

In ancient Greece, a symposium was a part of a banquet that took place after the meal. A symposiarch would decide how strong the wine will be served. This depends on whether serious deliberations will take place or merely for sensual pleasure. Therefore the strength of the wine dictates the mood of the evening.