After the harvest: trimming, drying, and curing to get the best from your buds
Once we have harvested, we find ourselves with a pile of branches, buds, and leaves, filling our environment with intoxicating aromas. Now, we must dry and, if possible, cure all that herb so that the biochemical processes that enhance cannabinoid effects can complete, while aromatic agents mature and chlorophyll breaks down.
Indeed, we already know (or should know) when and how to harvest according to our tastes and preferences. In any case, if it is your first harvest, the grower can experiment a bit if they have several plants from the same mother, by leaving a few days between harvesting each one and observing the changes in structure and trichomes. It is important to perform a detailed observation with a magnifying glass and take notes, so you can have good data to compare and draw conclusions at the end.
Trimming
Normally, we will have cut the plant below the last node with flowers if we are working indoors with small plants. If the harvest is from outdoors or a terrace with large containers, the size of the specimen usually makes it unmanageable even when harvested in parts, so it is common to separate the branches, some of which may be the size of an entire indoor plant. These can also be separated into parts for better handling.
Once we have the plants broken down into branches, we must perform an operation intended to lower the humidity and remove parts of the plant that are undesirable for smoking; as many of you know, this is called trimming, as it is somewhat similar to a haircut in that we peel the buds, leaving them smooth and without protruding parts. As you will see from experience, it is convenient to work with medium-sized, sharp, narrow-tipped scissors, like those used by hairdressers. We will start by removing all the main leaves that may have remained after the initial breakdown, trying to cut the base of the petiole or stem that joins the leaf to the branch, going over the entire branch without forgetting those that clearly protrude from the base of the buds.
This is a good time to observe the different developments of the plant depending on the area of the branch and relating them to the position the plant occupied in the grow space, so that we can draw conclusions regarding whether the plants were too close together, for example, or if they were too tall, in case the lower branches show loose and poorly formed flowers.
The leaves we have cut are usually useless for recreational use since they possess practically no trichomes and, therefore, no cannabinoids. In any case, they can be used as a spice to add flavor, or to prepare some oil or butter for medicinal use, since therapeutic doses are usually quite low.
From this moment, we have two options: hang the branches to dry as they are, or continue trimming. Some growers prefer to dry at this stage and finish trimming after drying and before curing. The advantage is that drying is slower, and some aromatic agents are protected. However, by the second phase, the herb is usually quite dry and brittle, and even the small outer leaves are folded over the bud, making them difficult to access. On the other hand, the heads of the trichomes detach very easily in this state, so by handling the branches, we lose some of them as we rub or bump them. That dust sometimes seen against the light when shaking a dry branch is mostly composed of tiny pieces of dried pistils and trichomes, in addition to possible insect remains, dust, etc.
For this and other reasons, and always based on our experience, it seems more beneficial to perform the complete trim when hanging to dry. Although some resin clearly remains on the scissors, it can be collected and smoked, and in any case, the amount is much less than what we would lose if we trimmed after drying. There is also the possibility of hanging to dry and performing the second part of the process after three or four days, at which point the stems do not yet snap and the buds have lost some moisture but retain enough so that the trichomes do not break. This solution can be valid, but if the variety is very resinous, we will have difficulty removing the outer layers of small leaves.
Thus, after pruning the main leaves, we will go over each bud, cutting all the tips of the leaves and trying to give a clear shape to the bud, which is not always spherical or oval, as it can have irregular shapes when grouped, especially at the tips. The goal is to remove as much plant matter as possible without cutting into the calyxes. Of course, these remains must be saved because, in this case, they do carry trichomes with sufficient density to obtain pollen or even be smoked.
It is useful to have a blade or cutter, or a container with alcohol and some gauze to clean the edge of the scissors every so often. You will quickly notice how the cutting edge is lost until the point where the leaves are practically being torn. We can clean them easily with gauze soaked in alcohol by passing it along the edges, although in this way we waste the resin. With a little more effort, we can separate the resin from the edges of the scissors by scraping with a blade and collecting the little balls that remain. Then we join them together, and in the end, we can have some joints of this “pseudo-charas,” which usually provides a stimulating and active effect.
Another point to keep in mind, and where experience is fundamental, is the structure presented by the different morphological categories that exist in narcotic cannabis. We are not referring to the specific variety we have harvested, but to the morphology that the floral tops present in terms of calyx density, their thickness, the size and thickness of the small nearby leaves, and the amount of visible gland. Depending on all these factors, we will perform a deeper or lighter trim, because if we treat a hard indica bud the same as a thin, low-density pure sativa, the latter will likely be reduced to nothing after drying. This also happens in general with the small buds from the lower parts or if they have received little light or are poorly formed. In these cases, it is convenient to perform a light trim, removing only the tips of the leaves and leaving the rest, which will later shelter the bud, giving it shape and some volume. We can always remove those little leaves when smoking if we find them unpleasant.
The correct way to handle the branch-bud assembly for trimming is always by holding the branch between two nodes so that we can easily move it on several axes, rotating it to the necessary side while with the other hand we shave the surface. The less we touch the buds, the better.
Drying
Drying is done for several reasons. The main one is that fresh or freshly harvested herb is difficult to handle, cannot be ground easily, joints go out, and the flavor is usually unpleasant, with a “field grass” tone always present. On the other hand, there is the chlorophyll, largely responsible for the hay-like taste. Furthermore, a large part of the cannabinoids are in their acid form (THCA, CBDA…) and need time and gas exchange to decarboxylate.
A curiosity that will surely be unknown to many is the fact that CBN is not found in the fresh plant, but is formed after a long process of transformation and degradation of other cannabinoids after the plant is cut. In fact, this discovery was made by Ross and Elsohly in 1997, at the University of Mississippi (Ross, S. A. and M. A. Elsohly, CBN & D9 THC concentration ratio as indicator of the age of stored marijuana samples, Bulletin on Narcotics, 1997, 50, 1-2: 139-147), during a research project aimed at determining the time elapsed since harvest by analyzing a given sample of narcotic cannabis suitable for consumption. In this way, they managed to establish a relationship between the THC degradation levels of a given sample and its CBN content at controlled temperature and humidity. Today we know that CBN has a clear influence on the type of psychoactivity, or rather, on the duration of the psychoactive effect, regulating in some way the effects produced by the combination of THC and CBD, the other main cannabinoids.
The ideal drying process would be one that manages to leave the material with between 20% and 30% of the moisture it contained at the beginning, over the course of ten to fifteen days, in total darkness. In this way, we will achieve buds with a spongy texture that are easily crumbled, sticky, and with a good smell. The color of the small pieces at the base of the leaves that we left during trimming should have taken on a pale or even yellowish hue, a clear sign of the decomposition of chlorophyll, the first step toward a good smell and taste when smoked.
The loss of volume will be clearly noticeable and will depend on the category of cannabis we are working with. The buds will have compacted if it is an indica or height-oriented line, or they will have thinned out in the case of sativa-dominant or pure strains. The stems should snap with a crackle without much effort, and the now-solid buds should detach easily. A good time to perform a tasting, as we will be able to better appreciate the important change that will occur after a good cure. It is always important to take notes at the time, as over time, perceptions blur and it becomes difficult to compare later.
From here, the goal is to maintain a slow process in the reduction of humidity, another 10% with a controlled gas exchange, so that the final chemical transformations occur in the resins until reaching the optimal point from our point of view regarding the combination of psychoactive effect and aromas and flavors in the air and when smoked, at which point we will store our stock so that it remains unaltered for as long as possible.
Curing
This process is much simpler to carry out than drying. To do this, we will need some type of opaque and airtight container. We will take each of the dried branches and, with extreme care, separate them bud by bud and place them in the container without pressing them. An opaque glass jar with an airtight lid can serve perfectly. Some prefer to make an intermediate step between drying and curing, leaving the herb for a few days in wooden boxes before moving it to the jars, which is perfectly valid, taking the precaution of not using excessively aromatic woods like certain types of cedar, as they tend to impart their aroma to the herb.
Once the buds are in the jar, it is closed and stored in a dark place. Since a slight supply of oxygen and humidity is still needed for the final chemical reactions to occur in the buds, we will open the jar once a day for a few minutes, then close it and store it again after that time.
The duration of the cure is quite subjective, as we all have our own tastes. The best way to know when the material is at its peak is to perform periodic tastings, at least once a week. This way we can notice the aromatic changes and variations in psychoactivity. A moment will come when these factors will be to our maximum liking, observing the fact that if the jars continue to be opened, the changes inside will also continue, so the time for storage arrives.
Storage
At this point, what we want is for our herb to be preserved for a long time in the conditions in which we decided the curing was complete, so we need to store it in such a way that those small gas exchanges no longer occur.
The simplest method is vacuum sealing. There are different systems on the market for this purpose that use bags or jars, but we are going to explain a simple way to transform the same jars we used for curing into vacuum jars. It is very simple: it involves buying three-way valves at the pharmacy, like those used for IV drips, for example. They are very cheap and easy to get. We will also use a large veterinary syringe.
We take the lid off the jar, make a hole in the center, insert the bottom part of the valve into it, and seal it with silicone. After letting enough time pass for the silicone to solidify and lose its characteristic smell, we place the lid back on the jar. Next, through the outlet of the valve, we extract the air with the help of the syringe. With this system, we can achieve vacuum levels of 90% or more, with the advantage that after opening the jar to extract material, we can vacuum seal it again without any difficulty.
Of course, the most efficient system is immersion in an inert gas like nitrogen or argon that displaces all the oxygen from the container, but its acquisition is usually expensive and difficult, in addition to the complexity of its handling.
Finally, once the jars are vacuum-sealed, we will store them in a cool, dark place. A constant temperature of about 5 degrees Celsius (41 degrees Fahrenheit) can keep the precious buds we deposited there unaltered for years.
