From THC Farmer (against the rules to link it here). I think this may be relevant to cobs as well as low and slo. I’ll get to it soon.
YarraSparra
Aug 11, 2014
If you are licenced and sell to dispensaries then you are in the business of manufacturing medicine and the grade of any pharmaceutical commodity should be of the utmost importance. If dispensaries become the source go to for the highest grade weed, they will inevitably become more popular. This means more sales, more tax to the government, thus politicians will be incentivised to push for national legalization. I believe a big part of producing med grade weed is in the curing process. However, there is serious conjecture between cultural curing practices and the science based methods used by large companies like GWPharma (no I don’t work for them and have no opinion about their products).
There are many pros & cons for fast curing weed with dehydrators as opposed to slow curing (in air). Slow curing in the presence of oxygen (and moisture) makes no logical sense - purely from a biochemical and pharmaceutical point of view - for one thing, slow curing causes the eventual yellow-browning of buds caused by polyphenol oxidases. This should be avoided to arrest the bio-chemical conversion of soluble nitrogen into ammonia since these soluble nitrogenous constituents can transform into aroma-bearing constituents at a later stage.
Consider the major components of a bud and the effects from scenesence and the environment. The obvious place to start is the trichomes. I will only briefly touch on cannabinoids and volatile terpenes, as there is already a ton of info out there. As most of you are already aware, CBN is an oxide of THC and CBD, but it is by no means the only break down product. As such, CBN content has been used by forensic specialists to quantify the original THC/CBD content. This is typically calculated at approximately a 1:6 ratio (this figure varies slightly depending on the study sited). That means if 2% of your weed is CBN, then 10% is other break down products of degraded THC/CBD. Oxidation, light, heat and moisture (which facilitates microbial and enzymatic activity) are all time dependent factors that contributing to the deterioration of trichomes.
Carbohydrates are important components too. Dried buds are composed mostly of lignocellulosic material. The beta bonds between residues of cellulose means this material is particularly resistant to hydrolysis with the exception of exogenous cellulases or acids secreted by pathogens such as molds, (plants do not make endogenous celluloytic enzymes as, to the detriment of plant growth, this would obviously be structurally counter productive). Moisture + time will facilitate this type of undesirable microbial activity. Furthermore, these pathogens will not liberate residues to enhance taste, but rather ferment them into alcohols and potentially generating ketones and aldehydes, and releasing CO2 in the process. (Remember CO2 has mass and I will talk about this next).
Pectins and starches, although present in much lower amounts than cellulosic material, account for the bulk of the remaining polysaccharide content. Residual starch related compounds, namely amylose and amylopectin affect the combustion rate of weed. Anecdotal reports suggests both impart a bitter irritating taste when smoking, although I haven’t managed to ascertain how or why this may be the case. Most of the glucose is liberated from starches by amylolytic activity within 2-3days post harvest. The initial high RH and elevated temps in a sealed chamber with dehydrators/dehumidifiers, promotes amylolytic activity. Extending the curing time past this point will liberate negligible amounts of soluble sugars at the cost of various degradative processes ultimately leading to deterioration of the buds.One of these processes is the oxidative respiration of starch-liberated glucose into CO2. This increases with time and leads to loss a significant loss of dry weight of the material. Most people are probably unaware of this.
Pigment degradation is said to enhance flavor. Both neophytadiene and phytol, from 2-ethyl-3-methymaleic acid, are generated by degradation of chlorophyll. I can’t find evidence that these compounds impart a more pleasant taste when combusted than chlorophyll, but there are tentative references in some literature that suggests this is the case. The issue is further complicated because chlorophyll is subject to a mutitude of other enzymatic processes and trying to deduce the aromatic qualities of all of these products under various combustion conditions would involve a fairly in-depth study. The same goes for carotenoids. At least 20 known smaller compounds arise from the oxidative cleavage of various bonds in carotenoids. Conserving the green/yellow color of weed indicates that the oxidation of polyphenols to dark colored pigments (oxidative enzymatic browning) has been successfully suppressed. Arresting pigment degradation may or may not be beneficial to taste - I’m sitting on the fence with this one. If someone in the field knows of some studies that provide an explanation of how any why this would be so, great, please join the discussion.
Other factors affecting taste may include hydrolysis of proteins into free amino acids and subsequent reaction of the free amino acids with free sugars to form amadori compounds, variable changes in polyphenols, degradation of terpenes and sugar esters into more volatile constituents, and the conversion of nitrate into nitrite.
That’s just a brief summary of some of the biochemical processes that take place in buds post harvest. Although plausible, there is a lack of explanations exactly how these break down products enhance taste upon combustion. I believe there may be a much simpler explanation which may be (at least part of) the reason, and probably over looked.
Fast cured weed, or properly freeze dried weed is highly desiccated when cured. Conversely, buds that have been air cured without dehydrators will typically retain a moisture content of 10-15%. A lower moisture content means the material will burn hotter, and compounds in the trichomes such as terpenes and other volatiles have a higher likely hood of undergoing pyrolysis (combusting into CO or CO2) instead of vaporizing. Unmodified volatiles will certainly impart a different (and possibly nicer) flavor to their pyrolytic breakdown products, and to me this seems like a much more plausible explanation for the “harsher taste” of fast cured weed - Occam’s razor.
So what does all this mean to the Layman? Slow curing weed and burping glass jars only exacerbates oxidative degradation (deterioration) of the bud. Although it’s “possible” some of these break down products impart a nicer flavor when smoked, it will come a the cost weight loss, overall quality and potency.
Now for the good news. Follow a simple methodology based on what I just discussed. Fast dry cure, then store in the dark, in the cold, with a sizeable quantity of desiccant, or in CO2 or nitrogen gas - you have many options. When it comes time to bag up, then and only then, is a single ‘burp’ (allowing rehydration of the buds to that 10-15% mark) required. You will know when the buds are ready when they are slightly sticky and pliable again. A little squeeze and sniff will be proof of all the goodness you have retained.
It’s of my humble opinion this is the most practical and logical way to retain weight, quality and potency, especially for the purposes of high grade med weed.