Coffee Chaff

Coffee chaff is the outer husk that comes off of coffee beans during the roasting process. It is a waste product and can be gotten for free from a coffee roaster. You'll need to contact them and ask if you can have their coffee chaff. You'll then need to pick it up from them.

Coffee chaff is not coffee grounds, so it cannot be gotten from any coffee shop unless they roast coffee beans. 

Coffee roasters get their coffee beans raw which are usually a red, yellow, or green in color. The roasting then turns them into the familiar light to a very dark brown color.

Since coffee chaff is treated as a waste by the coffee roaster, if you're able to get their chaff, it may have some trash or dirt in them and may come inconsistently (either moist or dry). To make coffee chaff bokashi, remove any contaminants and air dry them as much as possible especially if you're not sure how old is the chaff. If the coffee chaff was produced very recently, the less you need to worry about air drying them. However, the sooner you use it, the better. If you do not plan on turning the coffee chaff into bokashi anytime soon, then it is better to let it air dry in order to avoid mold growth.