techniques for a successful harvest:

These processes are focused on harvest and post harvest techniques to develop quality cannabis material. Most of these processes are being improved upon daily and should be adapted to the products you are wishing to develop. These are suggestions that have not been validated by the academic community.

Materials:

  • gloves

  • harvesting equipment (hand or machine)

  • transportation from field to drying facility

  • rope, string, tobacco sticks or wire hung in drying facility

  • digital humidity and temperature reader hanging in drying facility

  • moisture content reader (or you can send off for 3rd party analysis, $30)

  • dehumidifiers (depending on climate)

  • air conditioner

  • tarps

  • airtight storage containers

  • trimmers

  • boveda pacs (optional)

  • patience

step one: When to Harvest?

  1. Check with seed or clone providers for advise.

  2. Get a 30-100x magnifying lens to look at trichomes (glandular heads where cannabinoids are secreted). Start looking once you notice the stigma turning orange (hairlike strands).

  3. Trichomes will go from clear to opaque or cloudy white when matured. Cannabinoid degradation, specifically THC will degrade to CBN and change trichomes from white to light amber to dark amber due to environmental exposure. Some products contain high levels of CBN and therefore require a later harvest however for most cannabis products, harvesting when all trichomes are opaque/cloudy white is preferred.

  4. Make sure you have at least a day or two of dry weather before harvesting outdoors. It is not advised to harvest plants after rain.

  5. Equipment varies and final products should be considered when selecting what equipment is best for you. Here is a chart organized with various end products in mind.

Step two: what harvesting method to use?

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step three: Drying

  • It is advised to dry material in an enclosed as close to climate controlled facility that you have access to. Yes you can use covered barns, greenhouse etc. that are well ventilated with fans but climate control is the gold standard.

  • Good ventilation/air flow is key. Make sure your air flow is not counterproductive however and is not blowing trichomes off of your material. This can be prevented by cutting fans down or off as material drys.

  • Tarp the floors for easy cleaning. This is also a safety net in case any material falls to the ground.

  • If you are worried about mold and mildew, cutting your branches down to 12-16 inches is advised. This is also a good method for smokeable material. Also cut away any fan leaves or excess leaves. (you may want to save these for whole plant extracts or “biomass”)

  • Humidity = 45-60% (dehumidifiers can help achieve this)

  • Temperature = 60-70 degrees Fahrenheit (some terpenes could degrade at temperatures as low as 70 degrees Fahrenheit, air conditioners can help prevent this)

  • Time is dependent on humidity and temperature. Expect 3-24 days. Heat dryers should be used cautiously and only for specific products such as isolate or cannabinoid extract as some terpenes could be lost. Freeze dryers are something I am currently exploring further.

  • Lights should not be turned on during this process, light will naturally degrade phytochemicals.

  • Moisture content when drying is finished should be anywhere between 10-16%. Make sure before bagging that you pay attention to storage methods advised by your processor or equipment/supply companies. You may also want to finish up with a nice cure if entering the smokeable market.

  • Stems should snap not bend as a rule of thumb.

  • 3rd party testing of moisture content is also a possibility if you want to be 100% before storing.

step four: curing (only a standard for smokeable market currently)

  • Curing is a process employed specifically to enhance 1. flavor/aroma 2. potency

  • Flavor is maximized by allowing bacteria to naturally feast on chlorophyll during the curing process.

  • Potency is elevated by cannabinoids such as CBG, CBDa and THCa natural degrading to CBD and THC.

  • Manicure, trim and separate buds from stems.

  • Place in an airtight storage container of your choice. (glass jar, c-vault, rubbermaid, hemp sac, turkey basting bag etc.)

  • Humidity = drop 5% each day or every other day for a slow cure start at 65% and go to 55-50%. These values vary, experimentation is advised!

  • Temperature = 55-60 degrees fahrenheit

  • Breathing or more commonly known as “burping” your containers for up to 30 min/day for 1-2 weeks is advised to release CO2 and moisture. The smell of ammonia is a red light and indicates possible mold or that your product was too wet when you stored it. After 1-2 weeks this process can be reduced to every other day or once per week.

  • Optimal moisture content for smokeable is usually 10-12%. Ask your processor for specs though! You can also include humidity pacs that will maintain your moisture content such a boveda pacs.

Resources:

https://www.agweb.com/article/growing-hemp-for-cbd-seed-or-fiber-NAA-chris-bennett

https://catawba.ces.ncsu.edu/2019/02/drying-hemp-for-cbd-production/

https://www.leafly.com/news/growing/time-for-harvesting-cannabis

https://www.leafly.com/news/growing/drying-curing-cannabis

https://www.usahempcombine.com/faq/