Monitoring Hemp Moisture Levels
During the aeration process, it is possible for moisture to creep up or down the interior of the bin and to accumulate near access doors. For this reason, building a monitoring system and procedure should be carried out on a regular basis during the five to six weeks hemp is undergoing aeration.
A system capable of tracking multiple conditions within the storage facility should also be employed for long-term monitoring beyond the aeration period. These systems should be capable of tracking the following factors at a minimum:
- Ambient room temperature
- Ambient room moisture levels
- Localized moisture levels in specific regions of the storage room
There are two approaches to consider when building your moisture monitoring system:
1. Use An Automated Monitoring System
Monitoring systems are designed with cables that reach into aeration bins and test for hot spots. Some are designed to communicate with aeration systems, allowing hot spots to be neutralized as soon as they are detected.
Each cable in a monitoring system can monitor an entire bin with a 20-25 ft diameter in the space of a few hours, but multiple cables may be dropped into the same bin for greater coverage accuracy. Bins with diameters wider than 25 ft should use more than one cable to ensure total coverage.
2. The Manual Approach
Alternatively, growers can manually probe the grain in each bin, testing multiple regions at random to obtain a reliable cross-sampling. Be aware, however, that manual probing only allows for sampling of buds closest to the top access and bin bottom doors, leaving much of the bin contents out of reach, especially those aggregating towards the center. Manual probing is therefore best applied to smaller bins, and if more accurate monitoring equipment is not available or within a grower’s present budget.
Continue Monitoring After Aeration
After the 5-6 weeks needed for aeration and/or secondary drying have concluded, subsequent periodic monitoring should still be performed a few times per week while hemp is being stored awaiting delivery to the processor. Seasonal changes in particular should serve as prompts for moisture checking, as they necessarily bring with them changes in precipitation dynamics, be they changes in rainfall rate or consistency transitions such as snowfall replacing rain in the winter.
Remember that effective moisture control always begins and ends with a properly-implemented high quality storage system. Well-calibrated systems can do the lion’s share of monitoring and recalibrating air pressure and heating conditions predetermined by the grower during setup. Nevertheless, no mechanized solution can ever be a total substitute for human oversight, nor should it be, as due diligence and personal involvement with the crop at all stages of production have always been the hallmarks of the wise and ethical grower.
In a phrase, your mind should always be your sharpest tool. Only intimate knowledge of the news of a given crop and the conditions impacting those needs at any given moment in time will ensure that great equipment will produce equally great results.