Being a good Cantabridgian, I usually go to the locally-owned 1369 Coffee House here in Central Square. There have been occasions where I have gone to the evil Starbucks, though. While there, I remember seeing Tanzanian coffee. Now, I've seen it up close.
Mama Anna and her sisters showed us how the beans are roasted and how, as Mama Anna personally demonstrates in this picture, the beans are ground. The motion and the posture reminded me of watching someone churn butter.
Typically, Mama Anna will take the unground beans to the market, which is where they are bought by wholesellers. Those wholesellers in turn sell to places like Starbucks.