Most of us probably don’t think about walnuts all that often, other than maybe contemplating a sure-fire way to take a brownie from good to great. Yet these tasty treats truly are the product of some amazing science.
Getting a walnut’s flavor just right—and ensuring high-yield production—requires a careful balance during the drying process. Temperature must be kept under 110o F to not interfere with qualities of the nut’s oils. Moisture has to be kept to 8 percent: Too little, and the crop can mold, too much and the nuts may turn brittle and costly production resources are wasted.
At California-based Fedora Farms, a highly automated system using Opto 22 SNAP PAC controllers and I/O is aiding successful production. A custom set of radio frequency circuit boards from WECO monitors the “dielectric constant” of the nuts to determine moisture content. This method involves passing low frequency radio signals or electrical currents through the walnuts. Correlations are established between the conductivity of the product and the amount of moisture it contains. This moisture information is then used to guide the operation of a drying system that makes use of control fans and burners. So when the walnuts’ conductivity reaches a value predetermined as ideal, the drying process will be considered complete and automated doors will then release the nuts from their drying bins to continue on through shipping.
Making this complex operation even more amazing? It can all be done remotely!
