Was the correct grinder used?
The BCG111 model can be used for grinding spices. A spice grinding accessory is available that includes two shorter metal jars with plastic lids. One of the lids can be used to retain freshness, while the other is designed with holes to distribute the spices.
KitchenAid does not recommend grinding spices in the BCG100 model Blade Grinder. The reason for this is that this model was tested for coffee beans only, not spices. It is not recommended to operate the grinder for more than 25 seconds, most spices take longer than 25 seconds to grind, which could shorten the life of the motor. Also, there is a plastic seal below the blade in the grinder that will retain the flavor of the spices and affect the flavor of coffee that is later ground in the unit.
Blade coffee grinders are designed for grinding whole, unflavored coffee beans.
It is not recommended for extremely fine grinding such as for espresso machines. The reason for this is that the longer grinding time required for very fine grinds can overheat the coffee grinds causing a burnt or bitter taste in the coffee.