Curing is the final and most important process after harvest, determining the quality, flavor, and smoothness of the final product. This controlled aging method stabilizes the flower’s internal moisture content while allowing beneficial chemical changes to occur. Curing is often overlooked, but it is a necessary step to achieve a smooth consumption experience and maximize the flower’s aromatic and potency potential. It is a meticulous process of environmental control that ensures the harvest reaches its peak quality before consumption.
The Science of Curing
Curing facilitates crucial biological and chemical transformations within the harvested plant material. One primary goal is the degradation of chlorophyll, the green pigment responsible for photosynthesis. Chlorophyll breaks down into stable compounds through enzymatic activity that continues post-harvest. If this breakdown is rushed or incomplete, the residual chlorophyll imparts a harsh, “grassy” taste and a less-smooth smoke.
This slow, controlled process also plays a significant role in preserving and stabilizing the volatile aromatic compounds known as terpenes. Terpenes are responsible for the distinct flavors and scents of each cannabis variety. Improper drying or curing can cause them to evaporate prematurely. By maintaining a specific internal humidity, the curing environment protects these compounds, allowing the true, complex flavor profile to emerge.
The curing environment also influences the potency of the flower. While most cannabinoid conversion happens during the plant’s growth cycle, the conditions of the cure allow for the continued transformation of non-psychoactive cannabinoids. Specifically, the acidic precursor, tetrahydrocannabinolic acid (THCA), slowly converts into its active form, THC, which is the primary psychoactive compound. A proper cure ensures this conversion continues, maximizing the flower’s potential potency.
Pre-Cure Preparation: Achieving Optimal Dryness
Before the curing process can begin, the harvested flower must first be dried to a specific moisture level. Drying is the initial, rapid removal of exterior moisture, while curing is the slower, controlled homogenization of moisture from the interior to the exterior. Starting the cure too early, with excess moisture trapped inside, creates a perfect environment for mold growth that can ruin the entire harvest.
The target internal moisture content before jarring is between 10% and 12%. This range indicates that the flower is dry enough to inhibit microbial growth but still contains enough internal water to continue the beneficial chemical processes of the cure. Growers use a simple physical indicator known as the “snap test” to determine readiness.
To perform the snap test, a small stem should be bent: if it snaps cleanly with an audible crack, the flower is likely dry enough for curing. Thicker stems may still bend slightly rather than snapping, which is an acceptable indicator that the interior holds enough moisture to redistribute during the cure. If the buds are jarred too late, the result is a brittle, harsh product that cannot be salvaged by the curing process.
The Curing Methodology (The Burping Process)
The core of the curing process involves storing the dried flower in airtight containers, such as glass mason jars, and managing the internal environment through regular air exchange. The ideal storage environment is a cool, dark location with a stable temperature below 77°F (25°C) to prevent the degradation of volatile terpenes and cannabinoids. The containers should be filled loosely, leaving about 25% empty to allow for air circulation and movement of the flower.
Once sealed, the residual moisture trapped deep within the buds begins to migrate outward, raising the relative humidity (RH) inside the container. The goal is to maintain an internal RH range of 58% to 62% for an optimal cure. Monitoring this internal environment is done using a small digital hygrometer placed inside the jar.
The most important step is “burping,” which involves opening the sealed containers to release trapped moisture and exchange the stale air. During the first week of curing, the jars should be burped at least once, and often twice, daily for a few minutes. This releases excess moisture and carbon dioxide, a byproduct of the continued respiration of the plant material. This prevents an anaerobic environment that could produce off-flavors.
After the first week, as the internal humidity stabilizes, the frequency of burping can be gradually reduced. The flower may require burping once per day, then once every few days, and eventually once per week. This continuous monitoring and air exchange allows for a slow, even cure, ensuring the flower achieves maximum flavor and a smooth smoke.
Identifying and Addressing Common Curing Issues
Despite careful preparation, issues can arise during the curing process, with the most severe being mold or mildew. Mold thrives in stagnant, high-humidity environments, typically when the jar’s internal relative humidity exceeds 65%. Mold may appear as a gray or white fuzz, or the buds may develop a distinct, musty, or ammonia-like odor.
If mold is discovered, the affected buds must be discarded immediately, as consuming moldy flower poses a serious health risk. Spores can quickly contaminate the rest of the batch. If an ammonia smell is detected early, it indicates the buds were jarred too wet and anaerobic conditions are beginning. This requires the flower to be taken out and air-dried for a few hours before re-jarring and increasing the burping frequency.
The second common issue is over-drying, which results in brittle flower that feels crumbly and produces a harsh smoke. This occurs because the initial drying phase was too rapid or the flower was left too long without adequate internal moisture. Over-dried flower can be recovered by slowly reintroducing moisture using small, regulated humidity packs rated for 62% RH inside the jar.