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
How to Store Cannabis Long-Term and Preserve the Freshness
If you have a weed stash you haven’t touched for a bit, you may notice the buds getting dryer with time, and smoking them won’t get you as high as it did at first. While ageing is inevitable, it can be slowed down with proper preservation. We’ll teach you what can harm your buds with age, and how you can preserve them from time and the elements.
Keeping cannabis fresh is simple when you’re armed with the right knowledge.
If you’re the type to buy bud in bulk, or just don’t smoke too often, we can imagine you’ve ended up with old weed on your hands.
You can tell something’s off when you pinch the dried-up, lightweight nugs. You may need something to smoke, but would that old stuff even get you high at all? Even if it did, what would the flavour be like? No matter the answers, you’re most likely wondering how you can stop your weed from getting like that again.
Well, you can’t stop the ageing process, but you can definitely slow it down! Above all, you’ll need to make sure your weed is expertly cured, placed in optimal containers, and stored in a cool room at the proper temperature and humidity.
What Happens When Cannabis Gets Old?
Before we go deeper into that discussion, though, we want to offer you a deeper understanding of what happens when your weed starts to age.
As weed is exposed to heat, oxygen, and UV light, the cannabinoids within, including THC, will begin to break down. It doesn’t happen too quickly, but the change can become noticeable after a few weeks. It won’t leave you sober, but a joint won’t get you as high as the one you rolled when you first got it.
Conversion to CBN
As that THC breaks down, it doesn’t just disappear. In fact, it’s converted into another cannabinoid, known as CBN. This cannabinoid has some mild psychoactive properties, but it doesn’t get you high on its own. This conversion mainly occurs when weed is exposed to oxygen and heat, although the process takes time.
Lost THC won’t be the only consequence of keeping your weed in a warm spot. As it gets weaker, it’ll also taste and feel harsher upon smoking. This, of course, is a result of the terpenes drying out over time. Excessive light and moisture will bring about their downfall as well.
Does This Also Happen to CBD-Rich Bud?
If you’re more inclined to smoke CBD-rich strains, you may wonder whether any of this applies to you. Well, since CBD is also a cannabinoid, and since the buds also have terpenes, it too can degrade with age. The high isn’t a factor, but you’ll miss out on the other potential benefits of CBD.
What Causes Weed to Age?
We’ve alluded to certain causes of weed ageing, but let’s go ahead and break the issues down into clear terms.
You have to maintain a very precise balance when it comes to humidity and cannabis. If your storage method introduces too much moisture, you run the risk of mould infestation. If it isn’t humid enough, though, the terpenes and cannabinoids will end up withering away. While they’re quite different outcomes, the unpleasantness is equal between them.
Often going hand-in-hand with excess humidity, high temperatures can hasten the degradation of cannabinoids and terpenes. Generally, you should make sure your weed storage area doesn’t get hotter than 25.5ºC (78ºF). Simply enough, this is because any environment between 25.5–30ºC (78–86ºF) is prime for mildew and mould growth.
In short, persistent UV light will land a heavy blow on the impact on terpenes, THC, and other cannabinoids. This is especially problematic in tropical areas, where it joins forces with humidity and heat to harm your stash.
Lastly, while many aren’t even aware of this, your container’s base material can have a direct impact on your weed’s ageing process. See, while many place their weed in plastic containers, the material can cause your stash to “sweat”. This means, as with actual sweating, your plant will release its inner moisture. It’ll end up dry and harsh as a result.
Curing Pocket Box
How to Store Your Weed and Keep It Fresh
So, now that you know the enemies, you need to learn how to defend yourself and keep your weed fresh. Thankfully, it’s a fairly simple process, and you may already have everything you need to start storing your weed for a long period of time.
Really, the journey to proper cannabis storage begins with the post-harvest curing process. And, funnily enough, it involves maintaining the same sort of optimised environment for your flower. You’ll want to find a cool, dark, and moderately dry spot. Separate the buds, trim off the sugar leaves, and sort your stash into mason jars. Also, note that each jar should only be ¾ full.
With a few weeks of patience, you’ll be rewarded with fresh, smokable flowers. If you really want to ensure freshness, though, you’ll want to make sure no excess moisture gets trapped in your curing jars.
To accomplish that, we recommend utilising our specialised RQS Moisture Fighters. These plant-based sachets are designed to rest right in your stash jars, absorbing or releasing moisture according to the conditions. They’ll last up to four months, and just one 8g sachet will keep your personal stash fresh. If your jar’s a little heftier, there are sachets in sizes up to 67g available as well. Either way, you’ll want to select the ones that maintain 58% or 62% humidity. Get the former if you’re in a more humid environment, and the latter if you’re living in a dry climate.
“But how will I know if the sachet is still working? Do I need to open up the jar to check?”. Thankfully, no! They each feature a dot that changes colour depending on their condition, so you’ll know exactly when you need to replace them.
Humidity Control Pack
Use Air-Tight Glass/Ceramic Containers or Vacuum Bags
Once your buds have been sufficiently cured, we’d recommend you keep them in their mason jars. Considering how much damage oxygen can do, air-tight containers are the best choice you can make for your weed.
It can’t just be any container, though. As we mentioned before, plastic can actually hasten the ageing process, so Tupperware would be unwise. A glass or ceramic container, however, will keep it safe and fresh.
That being said, vacuum bags are also incredibly effective, as they’re naturally devoid of air.
Keep It Dark
Along with your container of choice being air-tight and glass/ceramic, it should also be opaque. Light can wreak havoc on your cannabis, and blacking out your jars can ensure total safety. Before that, however, you should make sure your curing room is completely dark (with the lights off) to begin with. With blacked-out jars, though, you can turn on the lights to check in without worrying too much.
As it turns out, our specialised RQS Re:stash Jars fulfill every one of the requirements you need your containers to meet. They’re layered with a jet-black silicone sleeve, boast air-tight lids made from hemp, and come in sizes of 4, 8, 12, and 16 ounces.
Maintain Cool Temperatures
Once you’ve got your buds in their containers, you’ll need to make sure the room stays consistently cool: below 25.5ºC (78ºF) to prevent mould from thriving. Turning it down to 21ºC (70ºF) would be optimal.
Ensure Clean Storage
Now, with almost everything in order, you just need to make sure things stay clean. Make sure you dust the shelves and jars, along with vacuuming or mopping the floor when needed. In turn, make sure you don’t spend too much time in there, as any dirt you track in will have to be cleaned up later.
Will Weed Stay Fresh When Frozen?
Through all of this, some of you may have been thinking, “I can keep food in the freezer for months, so why don’t I just freeze my cannabis?”. Others amongst you may hear someone suggest that and gag at the thought, thinking it ruins the flowers.
Those in the latter camp, however, may be surprised to learn that you can effectively store your bud in the freezer for 1–2 years. If you go for it, just make sure you’re very careful to avoid touching the buds, as the trichomes (which contain almost all of the resin) will quickly fall off.
Let them naturally thaw outside the freezer, and note the top layer of the buds may be sub-optimal. The rest of it, however, will be nearly as good as it was one or two years before.
Aged Buds: A New Trend?
To cap off our discussion, we thought we’d take a look at those people fighting against the notion of age being a detriment to cannabis. See, for some people, the curing process is an art form. For lovers of aged weed  , the prime flavour of a strain emerges with time, and some consider it necessary to wait at least five months after curing before smoking their stash.
This is still a very new school of thought, though. In general, we wouldn’t recommend trying it unless you have lengthy experience with cannabis. Yet, your journey with weed is your own, and we don’t want to stop you from experimenting!
While wine and cheese benefit from age, weed buds get dry and lose their potency. Here, we'll teach you how to preserve cannabis long-term and keep it fresh.