Freeze-Drying and Curing Cannabis Buds
Professor DeBacco
Not a New Method
The general concept has been around for many years and got its start in the food industry.
This is gaining popularity with cannabis since it can shorten the curing process to less than 2 days.
Some claim 24-36hour curing process
This can also be done by home growers and large scale commercial operations.
Hanging vs Freeze Drying
No Heat Needed
With the absence of heat with this curing process, the physical buds, cannabinoids and terpenes can be better preserved since they are “frozen” in time in a short curing cycle.
Reduced Curing Time
The reduced curing time not only makes the general process attractive to production growers, but there is the additional benefit of reducing the risk of mold or mildew developing during the process.
Phase 1: Deep Freeze
This is a quick freeze process, where the buds are exposed to -40F or colder temperatures.
The colder temperatures may be harder to achieve, but are advantageous to ensure maximum freshness.
However, temperatures below -80F have diminishing benefits.
The temperature should be maintained for at least 10 hours to help preserve the physical structures of the buds.
Phase 2: Sublimation
Sublimation: The process of changing from a solid to a gas without passing through an intermediate liquid phase.
This occurs in nature when ice and snow on the Earth’s surface changes into water vapor in the air without first melting into water.
The opposite of sublimation is “deposition”, where water vapor changes directly into ice such a snowflakes and frost.
During the curing process with cannabis a vacuum pump is used to reduce the pressure which changes the sublimation point.
There is controlled heat added to convert the frozen moisture directly into water vapor.
Capturing Water Vapor
With controlled systems the water vapor would be captured as ice to help ensure no terpenes are lost from the process.
The terpenes will have to be used in alternate products (not dry flower) such as vapes or oils.
Phase 3: Final Dry
During this process the temperature is raised to 70-80F which is when the water content is removed and it offers the growers the ability to adjust the amount of final moisture content that remains.
With controlled systems this water content is under grower regulation.
Link to Lecture Slides: https://drive.google.com/file/d/1hn7APwYX_ODl6n634aRxMpFpfl0LpKJs/view?usp=sharing
*Due to the description character limit the full work cited for “Freeze Drying and Curing Cannabis Buds” can be viewed at… https://drive.google.com/file/d/1mGQ1oKoKOjmh15oapvdVV6fxRxXnV71W/view?usp=sharing
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