I looked up spinach, a plant that has a high chlorophyll component. “spinach leaves chlorophyll smell like hay”. All weed references came up.
Wish I had an answer to that. I have had jars that smelled like the old grass in my lawnmower (not the ammonia wet grass but the dried up stuff), and also smell like straw or mulching hay. Best jar smells were after total control of the drying environment happened. 65F / 60RH for 10 days, 2 weeks, even longer has helped. Prior to setting up a dedicated tent for drying, it averaged 60RH, but swings could bring it from 40 to 80% RH. I think the swings to 40% dry it too much (maybe for a day or two), though I don’t know what process stops or changes. But something does…
Stabilizing your drying environment helps alot I believe… no science behind it, only my nose on my jars… But I’d love to learn what the actual reasons / processes are… the scientific ones 
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Please don’t bash me for this post, but I just can’t seem to recall where I got this info stuck in my head but I recall that the following parameters were considered ideal for drying your cannabis giving a superior smoke at the end. The numbers are what they are. 
60% humidity
60 degrees
6 weeks
I haven’t tried these numbers as I’m not in a position at the moment where I can achieve those numbers. I imagine that these numbers would work well though.
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I used to chop down the outdoor hidden grow, cut off the buds and put it all in paper grocery bags and put it in a large plastic kiddie pool I had up on rafters in the garage. I would leave it there for a couple of months before trimming it. I learned that leaving it alone for a few months like this cured it quite well
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No bashing, I have even taught for a short while and the only dumb questions students asked is when they were trying to be an ass. In our case here we do not know the answer so even wild ass guesses are legitimate until we weed them out. (ha ha) I don’t care who or where the answer comes from, I just want the answer. But on a brief look, I can not find what is taken as the answer to it in weed circles, that it is chlorophyll.
Just do it. Google “green plant smell”. Then “green plant smell hay”. It is good for a laugh.
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Color of dried herbs
The main objective of many herb-drying studies has been to improve the color of the dried products or reduce the color changes during drying and during storage (Baritaux et al. 1992). The color degradation in dried herbs is provoked by the degradation of pigments such as chlorophyll and anthocyanin. For green herbs, chlorophylls degradation is the most common change that may occur during the drying process (Rayaguru and Routray 2010). Lafeuille et al. (2014) analyzed chlorophylls and its colored derivatives in culinary herbs influenced by various drying processes. In the paper, a chlorophyll degradation ladder was designed to assess the dried herbs color after the drying process. The ladder was separated into four categories by the amount of green pigments preserved after the drying process: (1) no significant impact (> 90% preserved), (2) low impact (65–90% preserved). (3) medium impact (35–65% preserved), and (4) important impact (< 35% preserved). According to these criteria, freeze drying can be categorized into the first ladder as it showed no significant impact on the content of green chlorophyll derivatives. The most popular drying method, hot-air drying, was categorized into the second ladder. Sun drying falls into the forth category due to its significant impact on the preservation of green chlorophyll derivatives. Heat degradation pathways of chlorophyll have been described (Di Cesare et al. 2003).
https://www.tandfonline.com/doi/full/10.1080/10408398.2020.1765309
Freeze-Dried Buds Go From Stalk to Smoke in 24 Hours
When it comes to cannabis cultivation, patience is a virtue.
This is especially true when it comes to the curing process.
After many months of careful tending during the life cycle of the plant, the harvested buds endure another several weeks of drying and curing before the cannabis can finally be consumed.
Tracee McAfee and Greg Baughman knew there had to be a better way.
Cryo Cure machines utilize a proprietary five-step process.
Raw cannabis is frozen and subjected to extreme vacuum pressure.
The flower then goes through a sublimation process, wherein the frozen moisture content within is converted into vapor.
That vapor is then condensed in an ice bank and defrosts in the form of hydrosol liquid.
Image courtesy of Cryo Cure.
When all is said and done, the bright-green cannabis within retains more terpene and cannabinoid content than traditionally cured bud with no trichome deterioration.
“If you were to go and pick up cannabis from a local dispensary and put it under a microscope to take a look at those trichomes, they’ll look a lot like raisins, which shows the degradation of the flower,” explains Baughman, Cryo Cure’s President (McAfee is CEO). “Now, if you were to take a Cryo Cure sample and look at that under the microscope, you’ll see perfect elliptical trichomes without any degradation, shrinkage, or damage to them. We like to call it a ‘live resin flower.’”
Additionally, the Cryo Cure machine makes it easy to extract terpenes, thanks to the sublimation process.
There’s no doubt that cannabis put through the Cryo Cure process is different from traditionally-cured flower — and that’s a good thing.
Buds appear fluffy with an intensified color, befitting of any centerfold spread.
The aroma and flavors are rich and pungent, enticing anyone who gets within its scent.
They say any misconceptions, such as a decrease in yield due to less water weight, or a chlorophyll-taste due to the color of the bud, are quickly put to rest.
So freeze dried bud should smell like hay if chlorophyll is the reason.
Don’t know how I quoted myself in there, can not seem to get rid of it.
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A relevant paper.
Post-Harvest
After harvesting cannabis, it is manicured, cured, dried, and stored. Fresh cannabis material typically contains 78-80% moisture [39] and drying is necessary for handling, storage, and avoiding degradation of major cannabinoids before chemical examination. The Office of Medicinal Cannabis of the Dutch Government specifies that the water content of cannabis must be between 5% - 10% directly after packing [57]. Drying crops directly on the ground or under direct sunshine must be avoided [21]. Plants dry within 24 hours to 15% ± 2% moisture when spread evenly to a depth of approximately 15 cm at 40˚C [35]. Moisture content can be checked by measuring weight loss after drying for 24 hours at 105˚C. If the plants are hung to dry, the mean times taken to achieve 15% moisture were 36, 18, and 11 hours at 30˚C, 40˚C, and 50˚C, respectively [35]. When stored in paper bags to dry at 21˚C and 40% RH, fresh floral material cut from stems reached 11% ± 1% moisture in 5 days [47]. The dried material was then cured at 18˚C and 60% RH for 14 days before determining the floral dry weight [47]. Drying at temperature higher than 37˚C for 24 hours may decarboxylate cannabinoid acids [58]. The effect of high drying temperatures on cannabinoids and terpenes requires further investigation. To minimize loss of volatile terpenes during heating, another method for cannabinoid and terpene preservation is freezing by sublimation, which takes 10 to 20 days.
As oxidation occurs with the presence of light, heat, and oxygen, degradation of major cannabinoids is minimized after drying by storage in cool and dark places. Fresh products must be stored between 1˚C and 5˚C and frozen products must be kept at −18˚C to −20˚C for long-term storage [21]. The content of THC stored at −18˚C, 4˚C, and 22˚C ± 1˚C decomposed at rates of 3.83%, 5.38%, and 6.92% per year, respectively [59]. Samples can be stored at −18˚C or 4˚C for about 30 weeks before concentrations of THCA and THC change, however, samples stored at 22˚C ± 1˚C showed some immediate decomposition. Dried samples stored at 50˚C for 24 hours showed slight decarboxylation while those stored at 100˚C and 150˚C showed significant decarboxylation of THCA and decomposition of THC within two hours [60]. The effect of freeze-drying on terpenes has not been well-studied,
Flower
At East Fork Cultivars, Walker uses two different methods for drying hemp for CBD, depending on its final market. The hemp sold for premium flower, which fetches a wholesale price of up to $600 per pound, is hang dried on the stem in a climate-controlled building to preserve its look and quality. All the hemp flower sold as ingredients for use in products like beverages, topicals and tinctures is kiln dried.
“[Hang-drying] is a very laborious approach,” he admits. “The kiln-dried method is a more industrial approach … and [we use it] if the physical appearance of the flower and the flower structure doesn’t matter quite as much.”
Each climate-controlled building used to slow dry hemp has been insulated with spray foam and outfitted with commercial dehumidifiers. Walker also divided the buildings into zones, each with their own heating and cooling systems to maximize efficiency. “We’ve found that we can get the best quality by segmenting the buildings into smaller rooms for better climate control,” he says. “[The hemp] is dried for a full week and will remain on the stem for one to four months, allowing the chemical profile to settle and the moisture content to balance out.”
East Fork Cultivars tries to keep its slow-drying facility at 60% relative humidity, Walker says. Under these conditions, it takes a week to 10 days to fully dry the flower. The operation can also maintain a low temperature, which Walker says is important for maintaining terpenes and flower quality.
Postharvest, hemp contains up to 80% moisture, and drying helps preserve cannabinoids before extraction, per research published in the American Journal of Plant Sciences (AJPS). Kenneth Morrow, owner of cannabis R&D company and consultancy Trichome Technologies, says the optimal moisture content for cannabis and hemp flower is 8-12%.
Drying flower requires an optimal balance of humidity and temperature. Reducing moisture content to 15% can take anywhere from 11 to 36 hours when plants are hang dried at temperatures between 86°F and 122°F, per the AJPS. However, the research notes that drying hemp at temperatures above 37°C (98.6°F) could negatively impact cannabinoids and terpene levels.
The research also shows it takes fewer than five days to reach 11% moisture when material is stored in paper bags (versus hung) to dry in climate-controlled facilities where temperatures are 21°C (70°F) and relative humidity is 40%.
Andy Fogle, the chief operating officer of Nature’s Highway CBD, sells all of the hemp grown on the Neeses, S.C., farm as biomass and focuses on making the drying process as efficient as possible.
“The first year, we hang dried [our hemp]; it took a tremendous amount of square footage and it still didn’t dry that great,” Fogle admits. “We had 10 commercial dehumidifiers going, and the humidity levels would still be 90% in the mornings.”
Now, Fogle uses commercial belt-fed heating dryers to reduce moisture content, which he says are more effective and efficient than hang drying.
https://www.hempgrower.com/article/guide-to-hemp-harvest-part-two-drying-storage-fiber-grain-flower/
Flower
Careful storage is also essential for hemp flower; exposure to light, heat and oxygen can degrade cannabinoids.
Little research exists on the best storage for hemp grown for CBD, other minor cannabinoids and terpenes, but data published about cannabis storage in the AJPS found that fresh biomass stored at temperatures between 33.8°F and 41°F for 30 weeks maintained its THC level. However, storing at higher temperatures led to decomposition of THC. Ellison believes the impact on CBD would be similar, so growers should prioritize proper storage.
Will not let me post until someone else does to have participation. Only three posts in a row.
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Ok so I will post and you can continue with your fascinating research discussion. My growing just for myself, I keep simple, dry, store in amber mason jars with 49% packet. I believe longer you leave it better it gets
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So easy to go off on a tangent when looking up stuff.
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Here is another rabbit hole for you. I want to try this at some point. Anyone else tried it, what did you think? What strains would be best?
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But I thought it was cabbage that we bury.
The software is not happy with me.
" Let others join the conversation
This topic is clearly important to you – you’ve posted more than 36% of the replies here.
It could be even better if you gave other people space to share their points of view, too. Can you invite them over?"
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lol you got that message from the OG software?
thanks for all the info youve been gathering. ive been trying to get some myself to post, i just havent found anything close to what i want.
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yeah, you get messages like that when you reply to the same individual like 3x or more I think, without responding to others or the thread in general.
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The majority is always basic af — almost by definition. It’s best, then, to tailor our use of time for the minutiae of the discussion, and skip all of the basics. Hot dogs are available everywhere — we’re here for the Roe and the Marrow.
These would be the hay smells? Could you expand a bit on how a person breaks the double bonds, so we can elucidate how not to.
Also, I’ve heard offgassing of ethylene is a factor that needs to be considered, but the person was unable to come up with the paper that lead them to their conclusion. You have any thoughts?
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SOB, would have saved me some time if you posted that previously. I forgot about what was in his post.
What Are GLVs?
When plants are stressed or injured they respond by releasing biogenic volatile organic compounds (BVOCs). Green Leaf Volatiles are chemical compounds that belong to the BVOC group. GLVs are C6 molecules which rapidly produce when stress or injury occurs (3). Green Leaf Volatiles (GLVs) are widely produced across the plant kingdom and this more than likely includes the cannabis plant although there are no known scientific studies covering the topic. They are used to attract or repel predators and can be toxic to certain bacteria and fungi. GLVs are released as a result of mechanical damage and stress to the plant. This may serve as a warning signal to other plants in the surrounding area (1). Mechanical damage can create injuries for the plant and the different types of mechanical damage can include animals grazing on the plant, cutting the plant, or even roughly handling the plants can cause the plant to emit GLVs in high amounts. This is why intact plants will only produce very small or trace amounts of the chemical compounds known as GLVs and why wounded plants will emit GLVs in great amounts. Beyond this, the research into GLVs is limited (4).
Wet Trim v. Dry Trim
Wet trim is the process of removing buds from stalks or branches immediately after harvest whereas dry trim is the process of removing buds from stalks or branches after an initial drying or curing phase in between trim and harvest.
Many high-quality commercial grows will opt for a dry trim, allowing plants to hang dry for several days prior to trimming. The buds are then cured and eventually burped. This process helps bring out a rich aroma from the buds as they slowly dry. The wet trim process often gets frowned upon because of all the GLVs that are released from the rough handling and removal of fan leaves and some sugar leaves in a fast-paced environment. The GLVs can directly affect the smell and taste of your finished buds which is why it is important to avoid the rough handling of buds during harvest through curing. The smell of fresh cut grass is not too dissimilar with a mixture of oxygenated hydrocarbons being emitted from many green plants. Some of the oxygenated hydrocarbons include methanol, ethanol, acetaldehyde, and acetone. This is why improperly handled cannabis buds can have a strong smell of hay or cut grass.
Now this is just my first pass at this, as we know, anyone can print anything on the Web. I need to dig in a little deeper to confirm anything. I never took biology in school, just picked up some from my pain research. I did not delve into plants.
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Has a brief explanation on the chemicals and the fresh cut grass smell. The next question is what happens to these chemicals when we do not abuse the plants. Do they stick around, do they break down? Doubt I will find the answer nut I will keep mining the vein , I am a curious sort. Makes more sense than chlorophyll.
Need to clean house, why am I still messing around?
“While damaged cells produce mainly the aldehydes, neighboring intact cells are necessary to convert these into the corresponding alcohols and esters [24]. GLVs are almost immediately released locally from damaged tissue [15,16,17,18], but can also be produced systemically in response to herbivore damage [25]. Some plants emit GLV in a diel cycle with maximum emissions reported at the beginning of the scotophase, where this effect was found to be dependent on the availability of oxygen [26,27].”
And it goes on a bit, will read more later.
I can’t seem to give up.
https://www.cell.com/current-biology/pdf/S0960-9822(10)00241-1.pdf
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In my experience wet trimming either on or off the stem, jarring buds that are still too wet has caused a hay smell to me in the past.
To me if you trim wet buds and get a grass smell then dry too fast or too slow you’ll get a hay smell.
I have know scientific evidence just my experience
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Trimming doesn’t cause hay smell. Bad air exchange will and like you mentioned-when you don’t dry your buds enough and go to jars too early. I avoid jars now. Jars are for storage not curing IMO
Sub out your mason jar for an oven turkey bag!! You’ll never use a jar again I bet
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Ok it is the season I will pick up a few and try! Right now I am sealing dried and cured buds in Mylar food vac bags using an oxygen absorber packet per bag. Never have done this before with bud, great for dry or frozen foods.
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ooo yah now this thread has some juicy industry nuggets. That pubmed shit is off the hook, yo! There are definitely serious people studying cannabis drying and storage, great job @bunny!
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