There are three parts to a corncob: Chaff, which is also called beeswing, is on the outside of the cob; Pith is the softspongy center portion; and Woody-Ring, which forms between the Chaff and Pith.
The pith and chaff portions have a low bulk density which means that for a given volume of product, the weight is relatively low. In general, high volume and low weight translates to high freight costs for finished products. For some products, we increase the bulk density, by compressing the pith and chaff into pellets. The pellets are then reprocessed into various particle sizes.