Cannabis enthusiast and student of the art of solventless extraction
Curing is the process of slowly reducing moisture content in cannabis flowers within a controlled environment over multiple weeks or months. Although curing involves the evaporation of water content from cannabis, it’s not the same thing as the initial drying process which takes place immediately after harvest. First cannabis is harvested, then it’s hung to dry, then it’s cured. But what are the benefits to curing cannabis flowers, and is it always necessary?
Slowly curing fresh cannabis flowers helps the chlorophyll within the plant to degrade to lower levels, making the smoke smoother and more mellow. High chlorophyll content makes for a harsh smoke, a burn in the throat, and a taste of hay. Through curing cannabis, the chlorophyll within the flowers breaks down so it’s not as evident while smoking.
Curing also prepares the flowers for long-term storage. It’s important to have a low moisture content in the flowers when storing for long-term, to reduce the risk of microorganism growth which can ruin the product. Mold thrives in moist environments, so storing moist cannabis in a sealed jar will likely ruin the flowers. Once mold takes hold, it’s time to throw the cannabis away. But after a good cure, the flowers will be much less likely to grow mold.
Finally, curing allows for the cannabinoids to complete their transformation from acidic forms into non-acidic forms, which can provide a different dimension of therapeutic value. For example, THC-A is present in large amounts when the cannabis plant is first harvested, but over time this acid converts into THC. While THC is psychoactive, it’s acidic counterpart is not. So by properly drying and then curing cannabis, we get a more complete transformation of the cannabinoids into their non acidic and psychoactive form.
Should All Cannabis Be Cured?
Dried and cured cannabis flowers can be used for hash as well, but the premium hash on the market is often made with fresh frozen material. Learn more about fresh frozen cannabis in the article Fresh Frozen or Dried Flowers for Bubble Hash?
Curing also isn’t necessary if you’re pressing the flowers for rosin. Dried and cured flowers can be used to make rosin, but it’s not always ideal. With flower rosin, the fresher the flowers the better, so curing is normally avoided. For making flower rosin, the flowers only need to be dried until they reach 60-65% humidity, then they can be pressed. Additional curing will contribute to greater terpene loss, which lessens the therapeutic value of the final product.
However, to prepare flowers for smoking, curing is a must. Curing flowers will smooth out the flavor and bring out the very best in the cannabis. Curing allows the chlorophyll to break down and for the cannabinoids to convert into their most useful forms. Before curing, flowers aren’t considered ready to be smoked, even if they’re mostly dried. Curing is the last process of the many steps to growing and harvesting and preparing cannabis to be consumed. And if it’s overlooked or rushed it will be evident in the experience of smoking the flowers.
What Is the Right Environment for Curing?
Temperature, light, and oxygen are the main factors to consider when curing cannabis flowers. Cool temperatures in the 50’s or 60’s in a dark room with no oxygen exposure is the best environment. Light degrades cannabis, so it’s critical to avoid exposure to light. Storing in containers that are made with stainless steel and contain an air-tight seal is a great approach to curing flowers.
Choosing the correct storage container for curing is vital to a successful cure. Above all, don’t use a plastic container, as the material can interact with terpenes contained in the cannabis. Only glass or stainless steel should be used.
Toward the end of the curing process, it’s best to move the flowers to a totally air-tight container. A vacuum sealed container is the ideal vessel to use. This can be used during the curing process as well, and just opened up once a day for the first couple weeks of the cure. The main advantage of the vacuum sealed container is that it prevents oxygen from reaching the flowers. Oxygen allows the flowers to oxidize, which is a natural process that breaks down the beneficial terpenes, flavonoids, and cannabinoids in the flowers. If you eliminate oxygen you can stop or greatly slow down the process of oxidation. This is a major win in the preservation of cannabis.
How Long To Cure Cannabis Flowers
Curing starts once the flowers are mostly dried. When the flowers feel dense yet still somewhat squishy, and the stems snap instead of fold over when bent between the fingers, then it’s time to end the hang drying process and put the flowers in jars. Most growers trim the flowers after drying and before curing. Once the flowers go into sealed jars, the cure begins.
Since the flowers still contain moisture, the jars should be popped open for a few minutes each day. This lets some of the moisture escape and prevents stale and moist air from hosting mold and mildew growth. You only need to “burp” the jars every day for the first couple weeks of curing. After that, you can leave the lids sealed for the duration.
Eventually, most THC converts to CBN, which is a less-desirable cannabinoid known to induce sleepy and narcotic effects. It’s not as stimulating or capable of producing euphoria like THC. This starts to happen with very noticeable outcomes after several months of curing. 8 months is a good benchmark of a long cure. Beyond that, the buds can really start to degrade. However, proper storage techniques like using vacuum sealed containers and keeping temperatures low, will extend the window of optimum freshness for your flowers.
In general, look for a cure to take place from 2-8 months.
Curing cannabis flowers is essential if you plan to smoke them or keep them in storage outside of the freezer. The main exceptions are with fresh frozen material for bubble hash production, or if you're drying the flowers and then pressing right away to make flower rosin.
Be sure you're using the right container, either stainless steel or glass, for curing flowers. A vacuum sealed container is ideal. You can taste the buds as the cure continues to see how the flavor, aroma, and smoothness improves over time.
FREQUENTLY ASKED QUESTIONS
How long should I cure cannabis?
Curing flowers after drying is normally done in the 2-8 month range. After about 8 months the THC content in the flowers can significantly degrade, converting into CBN. This window can be extended if you’re storing in air-tight containers which reduces oxidation. Lower temperatures also helps preserve the cannabis for longer.
What’s the best container for curing cannabis?
The best containers are made of stainless steel or glass. Don't use plastic as the material will react with terpenes in the cannabis. A vacuum-sealed container is best for long-term curing/storage.
What’s the difference between curing and drying cannabis?
Curing takes place after the initial drying phase. While drying, cannabis is hung upside down and moisture leaves the cannabis in the open air and relatively quickly. Curing takes place in sealed jars and moisture is evaporated slowly.
What if I don’t cure my cannabis?
Cannabis that hasn't been cured will provide a harsh smoke. Although it may be dry, there is still a significant amount of chlorophyll. While curing, that chlorophyll degrades and the smoke becomes smoother.
What’s the best environment for curing cannabis flowers?
A cool, dark, dry place in an air-tight glass or stainless steel container.