Exerpt taken from the book: Marijuana Botany by Robert C. Clarcke.
Now, if you can read this in its entirety, you will learn a thing or two.......Real Science Folks!!!!!!!
Curing Floral Clusters
Harvesting, drying, curing, and storage of Cannabis
floral clusters to preserve and enhance appearance, taste,
and psychoactivity is often discussed among cultivators.
More floral clusters are ruined by poor handling after har-
vest than by any other single cause. When the plant is har-
vested, the production of fine floral clusters for smoking
begins. Cannabis floral clusters are harvested by two basic
methods: either individually, by cutting them from the
stalks and carefully packaging them in shallow boxes or
trays, or all simultaneously by uprooting or cutting off the
entire plant. In instances where the floral clusters mature
sequentially, individual harvest is used because the entire
plant is not ripe at any given time. Removing individual
clusters also makes drying easier and quicker because the
stalks are divided into shorter pieces. Floral clusters will
dry much more slowly if the plant is dried whole. This
means that all of the water in the plant must pass through
the stomata on the surface of the leaves and calyxes in-
stead of through cut stem ends. The stomata close soon
after harvest and drying is slowed since little water vapor
escapes.
Boiling attached Cannabis roots after harvesting whole
plants, but before drying, is an interesting technique. Origi
nally it was thought by cultivators that boiling the roots
would force resins to the floral clusters. In actuality, there
are very few resins within the vascular system of the plant
and most of the resins have been secreted in the heads of
glandular trichomes. Once resins are secreted they are no
longer water-soluble and are not part of the vascular sys-
tem. As a result, neither boiling nor any other process will
move resins and cannabinoids around the plant. However,
boiling the roots does lengthen the drying time of the
whole plant. Boiling the roots shocks the stomata of the
leaves and forces them to close immediately; less water
vapor is allowed to escape and the floral clusters dry more
slowly. If the leaves are left intact when drying, the water
evaporates through the leaves instead of through the
flowers.
Whole plants, limbs, and floral clusters are usually
hung upside down or laid out on screen trays to dry. Many
cultivators believe that hanging floral clusters upside-down
to dry makes the resins flow by gravity to the limb tips. As
with boiling roots, little if any transport of cannabinoids
and resins through the vascular system occurs after the
plant is harvested. Inverted drying does cause the leaves to
hang next to the floral clusters as they dry, and the resins
are protected from rubbing off during handling. Floral clus-
ters also appear more attractive and larger if they are hung
to dry. When laid out flat to dry, floral clusters usually
develop a flattened, slightly pressed profile, and the leaves
do not dry around the floral clusters and protect them.
Also, the floral clusters are usually turned to prevent spoil-
age; this requires extra handling. It is easy to bruise the
clusters during handling, and upon drying, bruised tissue
will turn dark green or brown. Resins are very fragile and
fall from the outside of the calyx if shaken. The less hand-
ling the floral clusters receive the better they look, taste
and smoke. Floral clusters, including large leaves and stems,
usually dry to about 25% of their original fresh weight.
When dry enough to store without the threat of mold, the
central stem of the floral cluster will snap briskly when
bent. Usually about 10% water remains in dry, stored Can-
nabis floral clusters prepared for smoking. If some water
content is not maintained, the resins will lose potency and
the clusters will disintegrate into a useless powder exposed
to decomposition by the atmosphere.
As floral clusters dry, and even after they are sealed
and packaged, they continue to cure. Curing removes the
unpleasant green taste and allows the resins and cannabi-
noids to finish ripening. Drying is merely the removal of
water from the floral clusters so they will be dry enough
to burn. Curing takes this process one step farther to pro-
duce tasty and psychoactive marijuana. If drying occurs
too rapidly, the green taste will be sealed into the tissues
and may remain there indefinitely. A floral cluster is not
dead after harvest any more than an apple is. Certain meta-
bolic activities take place for some time, much like the
ripening and eventual spoiling of an apple after it is picked.
During this period, cannabinoid acids decarboxylate into
the psychoactive cannabinoids and
terpenes isomerize to
create new polyterpenes with tastes and aromas different
from fresh floral clusters. It is suspected that cannabinoid
biosynthesis may also continue for a short time after har-
vest. Taste and aroma also improve as chlorophylls and
other pigments begin to break down. When floral clusters
are dried slowly they are kept at a humidity very near that
of the inside of the stomata. Alternatively, sealing and
opening bags or jars or clusters is a procedure that keeps
the humidity high within the container and allows the
periodic venting of gases given off during curing. It also
exposes the clusters to fresh air needed for proper curing.
If the container is airtight and not vented, then rot
from anaerobic bacteria and mold is often seen. Paper
boxes breathe air but also retain moisture and are often
used for curing Cannabis. Dry floral clusters are usually
trimmed of outer leaves just prior to smoking. This is
called manicuring.
The leaves act as a wrapper to protect the delicate
floral clusters. If manicured before drying, a significant
increase in the rate of THC breakdown occurs.
Storage
Cannabis floral clusters are best stored in a cool, dark
place. Refrigeration will retard the breakdown of canna-
binoids, but freezing has adverse effects. Freezing forces
moisture to the surface from the inside of the floral tissues
and this harms the resins secreted on the surface. Floral
clusters with the shade leaves intact are well protected
from abrasion and accidental removal of resins, but mani-
cured floral clusters are best tightly packed so they do not
rub together. Glass jars and plastic freezer bags are the
most common containers for the storage of floral clusters.
Polyethylene plastic sandwich or trash bags are not suited
to long-term storage since they breathe air and water vapor.
This may cause the floral clusters to dry out excessively
and lose potency. Heat-sealed boilable plastic pouches do
not breathe and are frequently used for storage. Glass
canning jars are also very air-tight, but glass breaks. It is
feared by some connoisseurs that plastic may also impart
an unpleasant taste to the floral clusters. In either case,
additional care is usually taken to protect the floral clus
ters from light so another opaque container is used to cover
the clear glass or plastic wrapping. Clusters are not sealed
permanently until they have finished curing. Curing in-
volves the presence of oxygen, and sealing floral clusters
will end the free exchange of oxygen and end curing. How-
ever, oxygen also causes the slow breakdown of THC to
CBN, so after the curing process is completed, the con-
tainer is completely sealed. Any oxygen present in the con-
tainer will be used up and no more can enter. Nitrogen has
been suggested as a packing medium because it is very non-
reactive and inexpensive. Jars or bags may be flooded with
nitrogen to displace air and then sealed. Vacuum-sealing
machines are available for Mason jars and may be modified
to vacuum-sealed bags.
The proper harvesting, curing, and storage of Cannabis
closes the season and completes' the life cycle. Cannabis is
certainly a plant of great economic potential and scientific
interest; its rich genetic diversity deserves preservation and
its possible beneficial uses deserve more research.
He who sows the ground with care and diligence
acquires greater stock of religious merit than he
could gain by the repetition of ten thousand
prayers.
-Zoroaster, Zend-avesta
