Caffeine is one of the most used substance all over the world. Ideally it should be consumed as less as possible. Find out Black Eye Coffee vs Yerba Mate Tea caffeine content in the following sections. However Black Eye Coffee Caffeine levels and Yerba Mate Tea Caffeine levels may differ with their brands, quantity of additives used, types of additives used etc. Below we have given you a generalized idea of safe levels of caffeine in Black Eye Coffee vs Yerba Mate Tea, their side effects and benefits.