James Duckenfield, CEO of Glass Pharms®, explains the company’s post-harvest process, including drying and curing, and why freeze-drying is never part of it
The science around medical cannabis cultivation often focuses on how the flower is grown. The environmental controls, the genetics, the cannabinoid and terpene profiles being targeted, and the cultivation methods used to help drive each plant towards its full potential. Yet what happens once the crop is harvested plays an equally important role in shaping the quality of the final product, the flower that is prescribed to patients across the UK.
Why post-harvest handling matters for medical cannabis flower
Harvest is an important milestone. That final day we work towards over a 12 to 16 week period, depending on the needs of the cultivar in question. But all the hard work our team pours into our medical cannabis cultivation programme would go to waste if we treated that flower as a finished product at harvest.
What we harvest is still a raw material, and everything that happens next determines whether the quality we’ve built over those 12 to 16 weeks makes it to the patients prescribed Glass Pharms products.
That journey has clear, defined stages. Each batch moves through a controlled series of post-harvest stages. This includes de-leafing, manual quality checks, drying, curing, and then storage, before being released to a pharmacy for dispensing. Every step is carried out in carefully managed conditions and documented thoroughly.
For medical cannabis entering the UK’s highly regulated supply chain, that documentation matters as much as the process itself.
Clinicians need to know that the products they are prescribing today are consistent with what they have offered patients previously. And it is equally important that patients who have found a treatment option that works for their health needs have access to a consistent product.
Drying and curing medical cannabis flower
To the uninitiated, drying and curing are often lumped together as two sides of the same coin. And while they are the two main stages of the post-harvest process, it is important to understand that they are separate, deliberate steps, each with its own purpose and its own controls.
Medical cannabis drying
The drying stage is where we slowly and carefully reduce the level of active water (aw) in the flower after harvest. This measures the water available within each flower for microorganisms and chemical reactions, rather than simply how much total moisture it still contains.
Dry too fast, and you risk degrading the terpene and cannabinoid profile. But if you dry too slowly, the remaining available water can create more favourable conditions for mould growth. It is a real Goldilocks type of situation, where balance is key.
At Glass Pharms, we use controlled water-activity drying, and target an aw of 0.60. This helps to ensure that bacteria, mould and yeast don’t proliferate during the drying period, while also protecting the cannabinoid and terpene profile of the flower. More on this further down.
Glass Pharms cultivation facility
Medical cannabis curing explained
The curing stage comes after the drying process has finished. This is a slower, gentler phase, and one that is also sensor-monitored throughout so we can see how each batch is progressing. For most cultivars, curing takes between two and three weeks, but it can stretch out longer. It is all dependent on what the batch in question needs.
That disparity is an important point, and why medical cannabis must be treated as a variable natural product working towards a fixed pharmaceutical standard, rather than something that always arrives as standard on a fixed timetable.
Curing is not simply a waiting period
As the flower cures, moisture facilitates the chemical reactions. When these reaction finishes the product becomes water-stable. When the flower enters the curing stage, there will always be a disparity between the moisture levels in the core of the bud and at its surface. Curing closes that gap, allowing the whole flower to settle at a consistent, shelf-stable moisture level.
It is also the stage where the character of the flower settles. The harshness of the dried material subsides, and the cannabinoid and terpene profile we have worked so hard to protect has time to stabilise. This is why it is crucial to allow curing to run its course, rather than applying a strict curing timeframe to each batch.
Freeze-drying is not part of the Glass Pharms post-harvest process
Glass Pharms does not use freeze-drying in the post-harvest process, and never has.
We say so directly because the terminology in the medical cannabis industry can sometimes be used a little loosely, with very different techniques being discussed as if they are interchangeable.
They are not.
Glass Pharms initially weighed up the benefits and restrictions of the two most established cannabis drying techniques: conventional hang drying and freeze-drying.
We settled on a different approach: controlled water activity drying.
One that gives us far more control over the condition of the final flower, including water activity, microbial quality, and the cannabinoid and terpene profile developed during cultivation.
Each of these three drying methods leaves the flower in a noticeably different condition.
Having assessed the limitations of hang-drying and freeze-drying, we believe controlled water activity drying offers the most appropriate balance for medical cannabis. It allows us to preserve the cannabinoids, terpenes, and trichomes developed during cultivation while controlling microbial levels so that irradiation is not required.
Being clear about the methods we use at Glass Pharms and the wider pharma-grade cultivation programme behind them helps patients, prescribers, pharmacies, and regulators understand the journey our products undergo before they leave our facility.
The post The science of the cannabis post-harvest process appeared first on Business of Cannabis.
Continue reading...
The science around medical cannabis cultivation often focuses on how the flower is grown. The environmental controls, the genetics, the cannabinoid and terpene profiles being targeted, and the cultivation methods used to help drive each plant towards its full potential. Yet what happens once the crop is harvested plays an equally important role in shaping the quality of the final product, the flower that is prescribed to patients across the UK.
Why post-harvest handling matters for medical cannabis flower
Harvest is an important milestone. That final day we work towards over a 12 to 16 week period, depending on the needs of the cultivar in question. But all the hard work our team pours into our medical cannabis cultivation programme would go to waste if we treated that flower as a finished product at harvest.
What we harvest is still a raw material, and everything that happens next determines whether the quality we’ve built over those 12 to 16 weeks makes it to the patients prescribed Glass Pharms products.
That journey has clear, defined stages. Each batch moves through a controlled series of post-harvest stages. This includes de-leafing, manual quality checks, drying, curing, and then storage, before being released to a pharmacy for dispensing. Every step is carried out in carefully managed conditions and documented thoroughly.
For medical cannabis entering the UK’s highly regulated supply chain, that documentation matters as much as the process itself.
Clinicians need to know that the products they are prescribing today are consistent with what they have offered patients previously. And it is equally important that patients who have found a treatment option that works for their health needs have access to a consistent product.
Drying and curing medical cannabis flower
To the uninitiated, drying and curing are often lumped together as two sides of the same coin. And while they are the two main stages of the post-harvest process, it is important to understand that they are separate, deliberate steps, each with its own purpose and its own controls.
Medical cannabis drying
The drying stage is where we slowly and carefully reduce the level of active water (aw) in the flower after harvest. This measures the water available within each flower for microorganisms and chemical reactions, rather than simply how much total moisture it still contains.
Dry too fast, and you risk degrading the terpene and cannabinoid profile. But if you dry too slowly, the remaining available water can create more favourable conditions for mould growth. It is a real Goldilocks type of situation, where balance is key.
At Glass Pharms, we use controlled water-activity drying, and target an aw of 0.60. This helps to ensure that bacteria, mould and yeast don’t proliferate during the drying period, while also protecting the cannabinoid and terpene profile of the flower. More on this further down.
Glass Pharms cultivation facility
Medical cannabis curing explained
The curing stage comes after the drying process has finished. This is a slower, gentler phase, and one that is also sensor-monitored throughout so we can see how each batch is progressing. For most cultivars, curing takes between two and three weeks, but it can stretch out longer. It is all dependent on what the batch in question needs.
That disparity is an important point, and why medical cannabis must be treated as a variable natural product working towards a fixed pharmaceutical standard, rather than something that always arrives as standard on a fixed timetable.
Curing is not simply a waiting period
As the flower cures, moisture facilitates the chemical reactions. When these reaction finishes the product becomes water-stable. When the flower enters the curing stage, there will always be a disparity between the moisture levels in the core of the bud and at its surface. Curing closes that gap, allowing the whole flower to settle at a consistent, shelf-stable moisture level.
It is also the stage where the character of the flower settles. The harshness of the dried material subsides, and the cannabinoid and terpene profile we have worked so hard to protect has time to stabilise. This is why it is crucial to allow curing to run its course, rather than applying a strict curing timeframe to each batch.
Freeze-drying is not part of the Glass Pharms post-harvest process
Glass Pharms does not use freeze-drying in the post-harvest process, and never has.
We say so directly because the terminology in the medical cannabis industry can sometimes be used a little loosely, with very different techniques being discussed as if they are interchangeable.
They are not.
Glass Pharms initially weighed up the benefits and restrictions of the two most established cannabis drying techniques: conventional hang drying and freeze-drying.
We settled on a different approach: controlled water activity drying.
One that gives us far more control over the condition of the final flower, including water activity, microbial quality, and the cannabinoid and terpene profile developed during cultivation.
- Hang drying is the most common drying method used across both the recreational and medical cannabis industries. It involves hanging the freshly harvested plants in a controlled environment until the buds reach their intended moisture levels.
- Freeze-drying, as we assessed it, desiccates the flower. This can result in the trichomes being potentially compromised and has the ability to destroy the terpene profile in the final product.
Each of these three drying methods leaves the flower in a noticeably different condition.
Having assessed the limitations of hang-drying and freeze-drying, we believe controlled water activity drying offers the most appropriate balance for medical cannabis. It allows us to preserve the cannabinoids, terpenes, and trichomes developed during cultivation while controlling microbial levels so that irradiation is not required.
Being clear about the methods we use at Glass Pharms and the wider pharma-grade cultivation programme behind them helps patients, prescribers, pharmacies, and regulators understand the journey our products undergo before they leave our facility.
The post The science of the cannabis post-harvest process appeared first on Business of Cannabis.
Continue reading...
