An adjustable grinder, includes a container, a stator, a rotor, a drum, and a rotary slide. The container can hold a product to be ground. The stator is positioned on the container. The rotor is positioned opposite to the stator and can rotate with respect to the stator. The drum is positioned around the rotor. The rotary slide includes a pointer that can be adjusted such that a distance between the stator and the rotor increases or decreases.