How to keep weed fresh
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- Moisture and mold in marijuana
- The best temperature to store your cannabis
- Light and oxygen change cannabis composition
- Extending the shelf life of weed
- Frequently asked questions
Over the years, cannabis packaging in legal or medical marijuana regions has become more sophisticated, with features designed to maintain freshness. The packaging on your marijuana products might have a harvest date on them, but flower doesn’t come with an expiration date. So even with producers improving their packaging, you might find yourself wondering: how long does weed stay fresh?
About the two worst ways you can store your bud are on a tray, exposed to oxygen and light, and in a plastic sandwich bag, just like a dealer’s bags that are common on the illicit market. A number of environmental factors affect how well the plant grows, but cannabis storage is also a key component of quality and freshness. Cannabis needs the right balance of conditions to remain fresh.
Cultivators go to great lengths to ensure your flower is packaged with optimal moisture content, usually in opaque packaging to keep light out. You’re probably wondering why you still see transparent and clear containers lining your dispensary’s shelves.
Well, old habits die hard and the practice of seeing and smelling the product on the shelf is still a key component for many people when it comes to deciding what to purchase. Some companies have even started replacing the oxygen in their packaged flowers with nitrogen to help maintain freshness.
For the best possible marijuana experience, you need to know how to keep weed fresh and how to store weed properly. This guide will give you everything you need to know.
Moisture and mold in marijuana
Moisture and water make a big difference when it comes to degrading the shelf life of cannabis.
While no two cultivators dry their flowers in the same way, all cultivators dry their flowers and then put them through a process called curing.
When cannabis is properly cured, it allows the moisture that is trapped inside the bud to slowly dissipate from the flower without changing any of the cannabinoids or losing terpenes. Once the flower has the perfect moisture content, usually between 6% and 9%, it is placed into packaging from which excess oxygen has been removed. When you take it home, it’s important to try to maintain that balance.
Once the flower has the perfect moisture content, it is placed into packaging from which excess oxygen has been removed. When you take it home, it’s important to try to maintain that balance. Photo by: Gina Coleman/Weedmaps
If you lose too much moisture, it can change the integrity of your flower. Your flower will become brittle and lose essential terpenes that affect potency and taste. On the other hand, with too much moisture or water, the consequences are more serious. So serious, in fact, that the American Society for Testing and Materials (ASTM), which develops technical standards across many industries, published the “Standard Specification for Maintaining Acceptable Water Activity (aw) Range (0.55 to 0.65) for Dry Cannabis Flower” in May 2018.
The ATSM defines water activity as “the (quantitative) capability of the cannabis flower in a sealed container to affect the humidity of the container’s headspace air.” Headspace is the air that surrounds the flower. Water activity measures vapor pressure against pure water. If water activity is 0.55, it is 55 percent of water.
During storage, water activity cannabis should remain within a range of a minimum of 0.55 and a maximum of 0.65. Water activity increases with temperature, which is why light and temperature control go hand-in-hand as best practices for how to keep weed fresh.
The relationship between moisture content and water activity is complicated, and the cannabis industry is still striving to determine the optimal moisture content for packaged flower.
What we know now is that a relative humidity level anywhere above 65% can significantly increase the likelihood that your weed will end up growing mold. According to the American Herbal Products Association, the drying process will dehydrate cannabis until it has a moisture content of less than 15%, and the curing process is where the remaining moisture is slowly removed to retain the volatile oils.
The best temperature to store your cannabis
To extend the shelf life of marijuana, it should be kept in a cool, dark place at or slightly below room temperature. The ideal temperature to store your weed is below 70 degrees Fahrenheit, or 21 degrees Celsius.
High temperatures combined with high moisture activity and relative humidity can lead to mold and mildew. Mold thrives between 32 and 120 degrees Fahrenheit, or 0 to 49 degrees Celsius, and growth is most active between 70 and 90 degrees Fahrenheit, or 21 to 32 degrees Celsius.
High temperatures and arid environments dry out your flower and evaporate sensitive terpenes, which ultimately change the effects and taste of the flower. This is why some cultivators skip drying and make live resin extracts to preserve all the monoterpenes that are lost during the drying process.
Lower temperatures are not as problematic, but they can make it harder for tetrahydrocannabinolic acid (THCA) to decarboxylate into tetrahydrocannabinol (THC). Lower temperatures will reduce the potency of the flowers when they are smoked or could make the trichomes brittle on the plant, causing them to break off when they are removed from the cold environment.
Light and oxygen change cannabis composition
Exposure to light is the biggest culprit when it comes to aging weed. This has been known since at least 1976, when a study published in the journal Pharmacy and Pharmacology explored what happens to the stability of cannabis under various conditions. It concluded that light is the single largest contributor to loss and deterioration of cannabinoids and suggested that “carefully prepared herbal or resin cannabis or extracts are reasonably stable for 1 to 2 years if stored in the dark at room temperature.”
Ultraviolet (UV) light will always degrade your weed, even if you store it safely in glass jars. So, while the clear glass Mason jars you see in the marketplace look nice, they won’t protect your purchase the way an opaque container will. If you really like to look at your marijuana, a brown container will filter out visible ultraviolet light — that’s why brewers use them to bottle beer. Meanwhile, green containers will block out roughly 30 percent of UV rays.
As time goes by, prolonged exposure to light and air will gradually convert THCA into THC. At the same time this is occurring, existing THC is being converted into cannabinol (CBN), a cannabinoid that does not create the intoxicating properties that THC delivers.
Ultraviolet (UV) light will always degrade your weed, even if you store it safely in glass jars. Photo by: Gina Coleman/Weedmaps
And it’s not just THC that’s affected. Cannabidiolic acid (CBDA) can transform into cannabidiol (CBD) with enough exposure, and THCV will degrade into CBV. During this time, your weed could potentially become less potent.
In addition to playing a role in the conversion of cannabinoids, oxygen can also oxidize essential terpenes and change the overall aroma of the flower into a grassy, haylike smell.
To reduce exposure to oxygen, make sure there aren’t many air pockets in your container. You should always store your weed in an airtight container. Don’t use very large containers to store small quantities of weed, as this leaves too much air inside the container with your herb.
Of course, it is inevitable that some amount of oxygen will get into your sealed package once it is open, but you can limit the amount of time that the jar is opened and the number of times it is opened.
If you store your weed in sealed bags, remove as much air as possible before sealing. Vacuum-sealing weed can be a reliable, long-term storage solution for your stash. If you go this route, be sure you follow these tips to avoid inadvertently damaging your weed:
- Try to avoid vacuum sealing your marijuana in plastic that contains bisphenol A (BPA). This chemical is a key ingredient in many types of plastic, but it has proven to be harmful to humans. And unfortunately, if you store your weed in plastic containing BPA, some of those dangerous chemicals could leach into your marijuana.
- Handle your weed delicately. Plastic easily builds up static charges that can pull trichomes off your buds. Trichomes are the cannabinoid- and terpene-rich hairlike glands all over cannabis flowers, so you’ll want to avoid damaging them.
If you plan on storing your vacuum-sealed weed in the freezer, know that freezing will also make your trichomes vulnerable to damage, as they will become brittle.
Extending the shelf life of weed
Knowing how to store weed properly will help you get the most out of your cannabis experience. Ultimately, the key to extending marijuana shelf life is all about limiting exposure to the elements. When it’s time to open your container, pull out your flower and immediately close your package. Don’t let it sit open, and avoid windy or highly ventilated areas.
To maintain the right level of moisture, use a salt-based control sachet to maintain the ideal relative humidity. According to the ASTM standards (D8197-18), “a salt-based control sachet designed to maintain a relative humidity of 0.55 to 0.65 in a sealed container can be used to maintain optimum storage conditions.”
Additionally, you can store your marijuana in a cannabis humidor box, which has been designed to maintain the ideal humidity for marijuana. There are currently several models available on the market.
Whatever you do, be sure you don’t use a cigar humidor to store your weed. Cigar humidors are typically lined with cedar wood. The oils in the wood help enhance the taste of cigars, but those same oils tend to harm cannabis. Similarly, humidors for cigars often use sponges or propylene glycol to create humidity that are ideal for tobacco, but are much too high for cannabis.
In the past, to remedy dry weed, people would add an orange peel to their bags to keep the moisture content, but this greatly increases the likelihood that mold would be introduced. In addition, the water activity of orange peels is unknown and the aroma of the peel could alter the flavor and aroma of your weed.
Nowadays, you can use the same humidity control packs, such as Boveda packs, to reintroduce moisture if it is too dehydrated. This will not reintroduce terpenes that were lost, but it will ensure that you don’t have a harsh smoking experience.
To keep your weed in tip-top shape as long as possible, take careful steps to avoid exposure to light, moisture, oxygen, and extreme temperatures. Photo by: Gina Coleman/Weedmaps
Like almost everything else, weed doesn’t last forever. Over time, changes to the molecular structure occur with exposure to heat, light, and moisture.
When cannabinoids and terpenes experience very high or very low temperatures, dry up, are exposed to too much moisture, or are left in the presence of light, chemical changes that will degrade the potency of the flower and could alter the taste and mouthfeel may occur.
As terpenes are exposed to environmental changes, they can oxidize or evaporate, creating a change in aroma and effects. And even though all weed degrades over time, the process can be slowed down if you control the temperature, moisture, and the amount of oxygen your flower is exposed to. To keep your weed in tip-top shape as long as possible, keep an eye on the harvest date on the packaging and take careful steps to avoid exposure to light, moisture, oxygen, and extreme temperatures.
Frequently asked questions
What’s the best smell-proof container for weed?
The simplest way to keep your stash smell proof is to make sure it’s stored in a solid airtight container with a sealable top. Sealable glass jars, like a Mason jar, are typically sufficient for storing your stash and keeping in the smell. Some cannabis consumers also use large medicine bottles to keep their stash from stinking up their living space. Online retailers also offer a variety of odor-proof containers designed specifically for weed storage.
Is refrigerating or freezing weed bad?
Refrigerating or freezing weed is definitely preferable to storing it in an area that’s too hot or humid. And though some cannabis consumers report successful long term weed storage through freezing, it’s more than possible to lose freshness and potency to icy temperatures, as trichomes may become brittle and break off more easily. Storing your stash in an opaque, sealed container, in a relatively cool place with minimal sunlight is your best bet for long term storage with minimal degradation.
How to keep weed fresh Copy article link to clipboard. Link copied to clipboard. Contents Moisture and mold in marijuana The best temperature to store your cannabis Light
Is Your Stash Bone-Dry? Rehydrate Your Cannabis Buds!
Have you ever seen a bud crumble to a powder when rolling a joint? Learn how to rehydrate your weed stash in record time with our three simple methods.
One of the worst things that can happen to your weed stash is to let it go bone-dry. If that’s happened to you, don’t worry, your buds aren’t helpless! With a little know-how, it’s possible to rehydrate cannabis using a few simple techniques.
Some of them may even bring in new flavours, while others can quickly destroy your stash if done recklessly. Nevertheless, your pot will never be exactly as it was before, but you can help restore it to its (nearly) former glory.
THE BEST METHOD OF ALL – PREVENTION
The two most common reasons weed gets dry beyond its optimal point are overdrying after harvest and inadequate storage.
Cannabis dries from the outside in. The outer leaves may seem dry, but the inner bud and stems might still hold considerable amounts of water. Therefore, it is common for growers to judge dryness by using the stem-snapping trick.
When you cut down your weed to dry, soon after, the stems lose a lot of their rigidity and stiffness. If you handle a stem, it will bend without snapping. As such, the general rule of thumb is, when you can snap a bud’s stem clean in half, it is sufficiently dry. If the stem still bends, it needs more time. While this trick works great for the more experienced, it is by no means the most scientific method.
In moderate climates with average humidity, expect a slow and even drying period. In arid climates, however, it’s essential to keep a humidifier close by.
Humidity Control Pack
USE HUMIDITY CONTROL PACKS TO MAINTAIN PERFECT MOISTURE LEVELS
After a final trim, buds should be placed in an airtight container to cure. Unfortunately, weed will continue to exchange water with the surrounding air, so, unless you look after them, your prized buds will end up bone-dry. Fortunately, one of the easiest ways to maintain the perfect environment for weed is with a moisture pack.
Not only do these nifty little packs work with harvests big and small, but the silicone gel inside takes over the job of exchanging moisture with the air around your buds. The result is a perfectly maintained relative humidity of 58–65%—the sweet spot for curing.
TOO LATE, MY WEED IS BONE DRY – WHAT TO DO NOW?
Fortunately, in the same way cannabis can release water into the air, it can also suck water molecules back into the bud.
The solution is relatively simple. All you need is an airtight container (again!), or something very close. In this remedial situation, being airtight is not essential to success. But after rehydration and for long-term storage, airtight containers are indeed necessary.
The general idea is to increase the relative humidity inside the container to create a microclimate. Water molecules will disperse from high concentration zones to lower concentration zones until it has evened out.
There are several ways to achieve this—some you can even do regardless of excessive dryness. All these methods are slight variations on one another (except for the super express methods described below), but they do have their nuances.
3 WAYS TO REHYDRATE YOUR WEED
BREAD SLICE, LETTUCE, OR DAMP PAPER TOWEL METHOD
This is a non-flavour-adding technique. Grab a slice of bread and moisten it (don’t soak it). Alternatively, lettuce leaves work great too. A damp paper towel can also be used, though beware of excessive water content.
Place it on top of the weed in a thick plastic or Ziploc bag, close it tight, and let it sit for an hour or two. When the time has elapsed, check your weed and move it around a little. Check the lettuce, bread, or towel for how much drier it is. This is a clear indication of the amount of water retained by the buds.
Depending on the size of your stash, you may need to repeat this a couple of times. The trick is to not rush it. For instance, do not excessively moisten the bread or leave the same lettuce leaf in there for too long. This could lead to the formation of mould, which could transfer onto the buds.
Inspect thoroughly, and when satisfied, move the weed to a proper airtight container for prolonged storage.
FRUIT PEEL METHOD
This trick adds a little fun factor and is great for experimentation. You can use several types of fruit peels and herbs to rehydrate your weed, in precisely the same way as described above. The difference is that there will also be a transference of taste and smell.
The most commonly used fruits are oranges and limes, as they are very useful in rehydrating your buds, but also lend their citrusy flavour to the weed. They should not be used for long-term storage and curing, as they could cause mould or bud rot. Daily close inspection is needed to avoid any sort of fungal outbreak. Simply substituting the peel every couple of days will ensure the added taste lingers.
Banana peels are also quite popular. Quicker in action too, but they also rot much quicker. Some people swear it makes the weed more potent, though there is no concrete evidence to support this. Apple peels do not transfer their taste quite as effectively, but they do release moisture slowly and consistently, which is great for even rehydration.
Regardless of your chosen fruit, the trick is to leave the peels with your buds for several hours. It can take anywhere from a few hours to a day until the buds are in good, smokable shape.
You can also add in things like mint, cilantro, rosemary, thyme, or any other fragrance-rich cooking herb. Not only will they work for rehydration, but they’ll also add a zing to your smoke.
HOT VAPOR METHOD
If you are in a hurry and cannot afford to wait that long, there is a way to speed up the procedure. But a big warning; you run the risk of cooking your weed or rendering it too soggy to smoke.
Grab a large pot, fill it with water, and bring to a boil. Once the water’s boiled, take the pot off the heat and place it on a safe surface. Next, cover the pot with a study cloth or piece of fabric, and secure it around the rim of the pot, making sure not to burn yourself (use oven mitts!).
Now, place your weed on top of the cloth, and let evaporation do the rest. The hot vapor will pass through the cloth and the buds, providing maximum hydration in record time.
Be sure to turn the buds regularly to distribute the vapor evenly. After 30 minutes to an hour, your buds should be ready to use!
Smoking overly dry weed is very harsh and unpleasant. Here are some simple tricks to rehydrate your buds in no time.