The present invention provides an apparatus for dry hulling harvested pistachios, utilizing an infeed hopper positioned adjacent an elongated rotatable drum having outer projections, wherein a first plate and a second plate are adjustably secured adjacent the drum. Adjustment of the position, angular displacement and gap space of the first plate, as well as adjustment of the gap space of the second plate, provides a configuration that may be adjusted in multiple parameters, including hulling force, dwell time and cutting force level, to optimize the hulling process to accommodate varying conditions of the pistachio product and enhance purity of the hulled product.
