is light really that bad for drying?

apexzer0

Member
I know that everyone says light is bad and degrades thc and thats why we dry and cure in the dark. I know light is harsh on just about everything. My question is this though. If light is so bad for thc then what is happening to the plant while its flowering up to the point that it is harvested? the trichomes are full of thc right? surely they dont say, "well, it's harvest time. lets start degrading." It is my understanding that thc converts to its psychoactive isomer in darkness while drying and curing. so is it really that light is attacking and destroying the thc like people make it sound or is the light simply preventing the thc from changing to the isomer needed to give it its potency?
 

smokinrav

Well-Known Member
I remember when it used to be, "don't dry in the sun" long before indoor growing got popular. But I believe that... Somehow the advent of indoor growing morphed this into no light when drying, and in this I have less faith, unless there's some testing that's been done for comparison that I don't know about. Always a possibility...
 

tip top toker

Well-Known Member
with regard to your last point, i cannot give you any scientific data to back it up (it may exist, it may not, i simply don't have any), but it has always been "said" that thc is built up over night, and get's broken down somewhat during the day, and repeat.
 

CaretakerDad

Well-Known Member
Light (photons) and CO2 are collected by the living plant during the daylight hours. The energy and CO2 are then processed into a number of things including ATP and carbohydrates needed for growth (of all kinds veg/flower) in what is known as the Calvin Cycle which takes place during the hours of darkness.

The drying/curing process results in decarboxilation which activates the psychoactive component of the THC. Light which contains UV as you acknowledge degrades everything it contacts - look at your dashboard, paint, curtains etc.

It is the timing of the Calvin Cycle and the growth that occurs during this time that is responsible for the THC level in your cannabis being slightly higher after the dark period.

Hope this helps :)
 

apexzer0

Member
Light (photons) and CO2 are collected by the living plant during the daylight hours. The energy and CO2 are then processed into a number of things including ATP and carbohydrates needed for growth (of all kinds veg/flower) in what is known as the Calvin Cycle which takes place during the hours of darkness.

The drying/curing process results in decarboxilation which activates the psychoactive component of the THC. Light which contains UV as you acknowledge degrades everything it contacts - look at your dashboard, paint, curtains etc.

It is the timing of the Calvin Cycle and the growth that occurs during this time that is responsible for the THC level in your cannabis being slightly higher after the dark period.

Hope this helps :)
This makes more sense, but how does decarboxylation cause an electron shift for the psychoactive isomer? Is there an enzyme that inhibits this change in light? Surely this is documented somewhere. I can't seem to find it though
 

bluerock

Active Member
I do my first stage drying right in the flower room that uses HPS lighting. The idea is to keep all the strong odor in one place. When it gets crispy, into the paper bags it goes for finishing. I have not noticed even the slightest change due to the HPS light exposure.
 

apexzer0

Member
This what I'm wanting to do cuz I don't want to have to stink up my whole drying outside my tent. Despite darkness being the accepted method I'm just not seeing the hard science to support it. I have a hard time believing the plant changes all of it's thc back and forth between isomers every day.

Have u tried light dry vs dark dry?
 

Jbone77

Well-Known Member
Iv dried in my flower tent, hung from the top getting indirect light from my 600, in a completely dark closet, and in a room with filtered sunlight, never noticed a difference other than I dont need extra fans and filters if I dry in my tent. I do keep my curing jars in a dark cabinet tho
 

bluerock

Active Member
Have u tried light dry vs dark dry?
Yes, that is how I was able to determine that no change was evident (with indirect HPS). I've also tried direct sunlight; no change in potency, but the finished product does taste more like tobacco. Of course, after drying is complete, it is sealed and stored in a cool, dark area for maximum shelf life.
 

bluerock

Active Member
this is what happens to a bud left in light for 3 weeks...loss of color... loss of potency
In what light? Sunlight? I don't think I've ever needed more than 5 days or so to crisp up a long branch in an indirect HPS situation. With direct sunlight, it is even less time, probably 3 days max. Longer in both cases for an entire plant (as opposed to drying individual branches). Sunlight will change the color and the flavor. How do you think those Mexicans dry their crop? Right out in the sun.
 

Sativied

Well-Known Member
The harvest still continues to respire and transpire after it's cut from the plant, the reason for the darkness is 'supposedly' to stop the cycle and not as much to prevent the light itself from damaging trichs or anything like that (opaque zips?). Temperature is way more important, which is why drying under HPS is usually a bad idea.
 

bluerock

Active Member
That's also why Mexican brick weed is shit....
Disagree that sun drying is the reason for poor quality imports. While I haven't had any brick in a long time, it was always hit and miss as I recall. Today, I don't know but like everything, I am sure there are different grades. Pretty sure that it isn't just premium female buds being bricked up. Can you see a bunch of Mexican peasants sitting around trimming bud in Mexico? I can't. More like hack those plants up and cram them in the brick press, all of them.
 

Lemon king

Well-Known Member
The harvest still continues to respire and transpire after it's cut from the plant, the reason for the darkness is 'supposedly' to stop the cycle and not as much to prevent the light itself from damaging trichs or anything like that (opaque zips?). Temperature is way more important, which is why drying under HPS is usually a bad idea.
which temps are best? 70-75degs???
 
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