Question about yerba mate: how often should I change the yerba?

Question

I know that serious mate drinkers keep adding hot water to the yerba, but when should you start worrying about bacteria? Also, is it bad to let the yerba get cold between infusions?

Answer 1

Until the mate's been sitting around for a long time, or gone completely flavorless from over-use it's considered "good." Sometimes hardcore South Americans continue to use the same worn out gourd full of mate until long into the night.

http://www.slashfood.com/2005/09/12/yerb...