In most places, the husks are used for compost or burned as fuel to power the coffee processing operation. In Yemen and Ethiopia, parchment is sold to make qishr. In Ethiopia, the equivalent of 12 cents would buy about a quart volume of husks. This beverage may be available in other coffee-growing areas, but I've only encountered it in these countries.
Like coffee itself, various levels of care and consumer preference produce different taste experiences. When fermented fruit from the coffee cherries is left mixed into the husks, the taste changes considerably. In my cups, the fruit seemed to have been culled before brewing.
Although I'd heard of this beverage, I didn't actually get a cup until I visited the lower Omo River. I accompanied my photographer wife, Jane, on one of her many visits among the tribes who still live traditionally along the river. On a few occasions we were invited to someone's ono (the Kara house made of sticks, roofed with long grasses) for buno. As is often the case with coffee (e.g. the Ethiopian coffee ceremony in the Highlands has its own elaborate protocols), the Kara rituals surrounding this simple beverage greatly enrich the experience.
Our camp was adjacent to the Kara village of Duss, and we were privileged to be invited to morning "coffee" with Ari and Karsche. The structure of this pre-dawn occasion was remarkable. The embers of the evening's fire are kept burning through the night. When Karsche arises, she revives the fire. The pot of water is put on the fire, and the husks are added to the boiling water.
Morning coffee occurs before dawn. No food is taken in the morning; this is breakfast. As invited guests arrive, they are seated according to gender and position or age. The man of the house always sits by the door, with a respected elder across from him. The other men sit to his left arranged by seniority, and the women sit on the opposite side, with the woman of the house by the fire.
The man of the house is served first, followed by important guests, the other men according to their seniority, and then the women. The buno is ladled from the pot into individual half-calabash gourds. Members of the household have specific ones reserved, just as we have our special mugs.
When all have been served, everyone waits for the host to begin. He blows across the surface, and he calls barjo (pronounced bario), the Kara (and Hamar) life force, as best I understand it. Barjo is everywhere. People have barjo, as do natural elements like clouds. Prospective bridegrooms are interviewed to evaluate their barjo. A person with the best barjo would be most harmoniously integrated into the society.
When there are no guests, the family still observes this ritual each morning.
When the man of the house is absent, as was the case on another occasion, his calabash is still served first. Later, after we had begun drinking, our hostess ladled from his calabash to hers, then added hot buno to each calabash. Serving the man's buno in his absence is to acknowledge his spirit in the ono.