Curing cannabis is the slow, controlled post-harvest process that occurs after the initial drying phase. This extended period of refinement transforms raw, dried plant material into a premium final product. The purpose of curing is to enhance the overall quality, flavor, and smoothness of the cannabis flower. This process ensures that the chemical composition within the plant matures properly, yielding a more enjoyable and potent experience.
Drying vs. Curing: Establishing the Foundation
The initial drying of cannabis is a rapid first step focused on removing the majority of external moisture from the freshly harvested buds. This phase typically takes several days to a week and is complete when the outer material is dry enough to prevent immediate mold or mildew growth. Proper drying is often indicated by a small stem snapping cleanly rather than bending, signifying a significant reduction in water content.
Curing is the distinct and much slower phase that begins once the buds are outwardly dry. It is a refinement process where internal moisture from the core of the bud slowly migrates to the surface, allowing for an even distribution of moisture. If the initial drying is rushed, the final product often retains a harsh, hay-like flavor that curing cannot fully correct.
The Curing Process: Controlled Environment and Time
Curing is a hands-on process that begins once the dried plant material is placed into airtight containers, such as glass jars or food-grade bins. The containers should be filled roughly 75% full to allow for air circulation around the buds. This confined environment is necessary to begin the gradual, internal chemical changes that define the cure.
Environmental control is a specific factor in this process, with the ideal temperature range maintained between 60–70°F (15–21°C) in a dark location. Monitoring the relative humidity (RH) inside the container is important, with the target range being 58–62% RH to facilitate the slow moisture and chemical exchange without risking mold growth. Humidity levels above 65% can quickly lead to the development of mold.
A critical action in this phase is “burping,” which involves briefly opening the containers daily, or multiple times per day during the first week. Burping serves to release excess moisture and to vent metabolic gasses, such as carbon dioxide, that are produced during the initial breakdown of plant material. This exchange also replenishes the oxygen supply, which helps to drive the desired chemical reactions. As the cure progresses, usually over a period of two weeks to a month, the frequency of burping can be reduced.
Chemical Transformation and Quality Enhancement
The slow, controlled conditions of curing allow for several beneficial molecular changes that directly enhance the final product’s quality. One key transformation is the enzymatic breakdown of residual chlorophyll within the plant material. Chlorophyll, the pigment responsible for the plant’s green color, contains magnesium and other compounds that contribute to a sharp, “grassy” or “harsh” taste and smell when combusted.
As the chlorophyll breaks down, these unpleasant characteristics dissipate, leading to a much smoother and less irritating experience. Simultaneously, the low temperatures and controlled environment of the cure help to preserve volatile terpenes, the aromatic compounds responsible for the distinct scent and flavor profiles of different strains. Terpenes are highly sensitive to heat and rapid drying, which can cause them to evaporate quickly.
Slower curing minimizes this loss, retaining a richer, more complex aroma and flavor profile. Another important chemical change involves the maturation of cannabinoids, specifically the conversion of non-psychoactive tetrahydrocannabinolic acid (THCA) into its final form. Curing contributes to a more stable product with better long-term preservation of its potency and effects.