Slow Drying Is Not The Way

[Green Genius]

After testing and R&D on cold dry and cure fridges, talking and collaborrating with some US based sources, we have come to the acceptance that cold, low and slow is entirely incorrect for drying.

Please read the original work and we will quote highlights

The Science Behind Optimal Post-Harvest Practices revealed: Unveiling

The Science Behind Optimal Cannabis Cultivation revealed: Unveiling the Truth About Drying and Preservation Techniques In a groundbreaking exposé, The Deep End brings to light the hidden secrets of cannabis cultivation that could revolutionize the industry. Through meticulous research and...

sharkmousefarms.com

 

[Green Genius]

Drying your fresh flower in conditions in the 60f/60% rh range, known as the “low and Slow” method contends that if we dry our flower at the lowest possible temperature,and lowest vapor pressure possible, that we can slow the rate of evaporation in that flower, preventing them from reaching their dry target before compounds like chlorophyll and sugars have a chance to degrade, while mitigating excessive evaporative forces that can pull out those secondary metabolites and volatile compounds. In our heads, the idea that cooler temperatures will prevent the oxidization of those precious compounds. And knowing that a safe water activity (aW0 of 0.64 is necessary for not only safe storage, and the prevention of mold and yeast, but also to ensure ideal consumption conditions as to prevent overly moist, or over-dried flower. These ideas, align with the notion that “Low and slow” is the ideal way to achieve those conditions. If we add to the fact, that out of context, the formula Water activity is equal to equilibrium relative humidity divided by 100: (a w = ERH/100) where ERH is the equilibrium relative humidity (%) ie. 0.64= 64%/100, it all seems to indicate that 60/60 is the right move!!!

 

[Green Genius]

The problem is, thats not how thermodynamics work!


According to Fick's first law: Movement of particles from high to low concentration (diffusive flux) is directly proportional to the particle's concentration gradient. What does that mean for us?


The evaporative forces of the surrounding environment are directly proportional to the density of the material it has to be pulled from. Diffusion works a lot like osmosis. Areas of high moisture will move to areas of low moisture until it equalises. If youve ever run the “Low and slow” method, you’ll recognize the “dry” flower feel after only 2 days. Then several days later, its back to moist again. As the moisture on the surface of the flower evaporates into the ambient atmosphere, the principal of water adhesion is still applied. Surface water getting pulled out of the flower, draws moisture from deeper within the flower toward the surface. But those same evaporative forces, based on ficks’s law, overwhelm those adhesion forces the deeper into the flower material we get, at at some point, that chain breaks, and that internal moisture is now being pulled out with significantly less force than it was at full moisture content %. While the concentration gradient has increased, so has the membrane thickness ( the amount of layers of flower the moisture has to diffuse through until it gets to the surface.

 

[Green Genius]

If we use the Caryophyllene as an example. The sample dried at 25 degrees celsius vs the sample dried at 32 degrees saw a Caryophyllene total difference from 1.91% to 1.86 % a 2.6 % overall reduction. If we extrapolate the findings from Ross and ElSohly , who ***measured a 31.0, 44.8, and 55.2% loss of terpene content in Cannabis sativa inflorescence which had been air dried and stored for 1 week, 1 month, and 3 months, respectively, as compared to freshly harvested inflorescence (Ross and ElSohly 1996).**

 

[Green Genius]

TLDR:

We want to begin our dry phase in a precise climate of 72 degrees fahrenheit, or 22.2 degrees celsius at 55% relative humidity and a 1.2 kPa, over the course of 48 hours. This is considered our phase 1 of drying and will begin that process of evaporating that surface moisture, while pulling the inner moisture of your flower toward the surface through adhesion. After the initial 48 hours, we will increase our pressure slightly, as a transition to phase 2. By increasing the tef, or mp and kPa to 74f, or 23.3c, and 1.39 kPA respectively, while reducing our rh% to 52%, we increase the rate of transpiration, while not overwhelming adhesion, leaving that chain intact as that moisture is pulled closer to the surface. After a 24 hour adjustment period. We move into the final phase of our dry, which is phase 2. Increasing temperature and VPD to 75 degrees fahrenheit or 23.9 degrees celsius, and 1.5 kPa for the final 48 hours will reduce the remaining moisture content in the near-surface layers down to a final dry moisture content of 10%.

 

[Green Genius]

We have just completed a successful test and will never be returning to 16/60 etc.

 

[benn0]

Interesting! Will still continue to hang excess flower upside in me shed for the winter though!

 

[VinDeezle]

Interesting findings. I've always dried a bit faster myself. Usually 5-6 days usually as I lack the ability to control environment properly and go for the usual slow dry that's recommended. As long as I'm in the mid 20s and around 50-60% I'm happy to hang.

 

[Green Genius]

Interesting findings. I've always dried a bit faster myself. Usually 5-6 days usually as I lack the ability to control environment properly and go for the usual slow dry that's recommended. As long as I'm in the mid 20s and around 50-60% I'm happy to hang.

Turns out thats close to ideal. The goal as it turns out is to get it down to curing conditions for long term storage as fast as safely possible. Quite long involved curing process as we are storing at ~65% moisture and slowly bring that down to 62-60%.

 

[Old fox]

There is so much science/medicine that we still don't know about optimal cannabis harvest and use. This dry/cure article is just one example.

 

[Sedge]

5 or 6 days in my opinion is far from ideal,,
I always aim for two weeks but they are usually done in 12 days ,,any sooner with most strains and flavour is compromised,,
I still can’t get over how everyone reckons 62% humidity is the best ,,you gotta remember those 62% bovedas were made for cigars,not for weed.
My humble opinion is that 58% Integra are better for long term weed storage than the bovedas.
I don’t worry about humidity percentages when drying as I’m not going to use machines to control that ,,the paper bags I dry in help slow things down in summer ,and help prolong the process in winter..
Each to his own but I’ll stick with what I know to be best for me.

 

[Green Genius]

5 or 6 days in my opinion is far from ideal,,
I always aim for two weeks but they are usually done in 12 days ,,any sooner with most strains and flavour is compromised,,

As shown by the data terpene loss is >20% of 14 day air dry. We also held the same opinion. But as we learnt it was entirely without merit.

I still can’t get over how everyone reckons 62% humidity is the best ,,you gotta remember those 62% bovedas were made for cigars,not for weed.
My humble opinion is that 58% Integra are better for long term weed storage than the bovedas.

Bovedas arent recommended to be used at all.

I don’t worry about humidity percentages when drying as I’m not going to use machines to control that ,,the paper bags I dry in help slow things down in summer ,and help prolong the process in winter..
Each to his own but I’ll stick with what I know to be best for me.

This is like VPD. You can grow without controlling it. But if you want to progress and excel, then you have to do the 1%'s in all areas. All this is pointing out is the science behind optimal drying.

 

[Green Genius]

To clarify we spent 10K and 4 months investing and R&D work on cold dry & cure. This was a tough pill to swallow and was a hit to the ego to admit it was the wrong path.

 

[Sedge]

So where and how did you come up with the 62% you mentioned ?

 

[Green Genius]

So where and how did you come up with the 62% you mentioned ?

62% is the highest % you want for short to medium term storage. Its also the highest % for smoking. 59% is optimal for long term storage.

So theoretically you want to be stable at 62% at the end of the initial 14 day cure, which is low and slow. This gives maximum weight and terpenes and allows you to adjust from there as needed. 62% can go to 59, but 59% cant go to 62...

 

[VinDeezle]

I had zero science involved in my methods. I just know the longer i hang the plants in the tebt, the longer it takes for me to get smell back when I cure for some reason. Plus it was always an effort full stop to slow the drying process down to more than a week due to Qld weather most of the year.

Dropped down to a 5-7 day dry and haven't noticed any quality difference as they still end up spending a good amount of time in jars curing.

I suppose on my end it's all conjecture anyways and just something to make me feel like I'm more involved than I am.

 

[Goonie Goat]

So theoretically you want to be stable at 62% at the end of the initial 14 day cure, which is low and slow.

Curing is still part of the drying process isn't it

 

[Green Genius]

Curing is still part of the drying process isn't it

Not apparently. It needs to be entirely separate process with its own conditions. Minimal oxygen exposure, sub 20c & 60% rH storage conditions. We arent really removing moisture anymore, we are equalizing it and allowing chlorophyll to breakdown further.

Flower can be smoked without curing, flower cannot be smoked without drying.

 

[Goonie Goat]

Not apparently. It needs to be entirely separate process with its own conditions. Minimal oxygen exposure, sub 20c & 60% rH storage conditions. We arent really removing moisture anymore, we are equalizing it and allowing chlorophyll to breakdown further.

Flower can be smoked without curing, flower cannot be smoked without drying.

I jar mine early (don't go by the stems snapping just when they feel dry), sweat them out until they go back up to 68-70%, throw them back into paper bags in and out of jars until they read 65% then just burp the rest of the time down to 58%-60%. Hope I'm doing it right . That's the best I can do for now

 

[VinDeezle]

I jar mine early (don't go by the stems snapping just when they feel dry), sweat them out until they go back up to 68-70%, throw them back into paper bags in and out of jars until they read 65% then just burp the rest of the time down to 58%-60%. Hope I'm doing it right . That's the best I can do for now

pretty much how I do it. When the stems double over like straws, but not snap. Ill jar it up with some stem left on. Usually ends up at like 67-68% after they've drawn all the moisture out from the stems and then I remove the stems and burp down to high 50s, low 60s.