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 Long Does Weed Stay Fresh?
There’s nothing better than fresh weed. The smell, the taste, the stickiness all make for a great experience. But if you’ve had some weed sitting around for a while, or you just found a stash in your ski bag or in the back of a drawer, you may be wondering “how long does weed stay fresh?” or “how long does weed last?” and you’re not alone.
Cannabis doesn’t necessarily have an expiration date, as you can safely consume it for as long as you like, but it will indeed lose potency over time which will result in a less than “high” feeling. If you’ve come across some weed from who knows when and want to smoke it, by all means, go ahead. What happens if you smoke super old weed? Not much, unfortunately.
How Long Does Weed Stay Fresh?
Under ideal storage conditions, cannabis can actually last quite a while. What are the ideal storage conditions to keep weed fresh? Whether you have strong smelling flower, need to keep it safely away from children, or just want to get the bang for your buck and help your weed last long, there are some basic storage needs you’ll need:
- Humidity control
- Airtight or vacuum seal
- Zero light (natural or artificial)
- Temperature control
When stored properly and with care, weed can last up to a year or longer. If you love having a selection of strains but don’t smoke all of them very often, a humidifier storage solution will be your best bet. Check out these rad and functional storage solutions from High Times .
Even if you store your weed in a plastic baggie in a drawer, you’ll still get a good six months out of it before it loses potency and goes through some pretty scientific changes.
The Science of How Long Weed Lasts
As with everything, science plays a major role in how long weed lasts and stays fresh. Even if your weed isn’t super fresh, you’re probably wondering if the THC stays potent.
When weed is left in unsavory conditions for too long, it can begin to decompose and the cannabinoid, THC, will actually change into CBN (cannabinol) which is known to be present in high amounts with aged weed. CBN is derived from tetrahydrocannabinolic acid (THC-A) and is created when THC-A oxidizes.
This oxidation happens over time as the chemicals and cannabinoids break down, and this process will reduce the potency of the weed. This is reason to consume your weed within six months of buying it. In addition to THC potency, the terpenes will also break down and that’s where flavor and scent are lost.
If you smoke old weed, it’ll likely look like dust and not smell or taste like much of anything. Dusty weed won’t harm you, it just won’t be pleasurable to smoke and it could make your throat feel scratchy or conjure up some coughs. In some cases, old bud can take on a bad taste or smell, and that’s when you want to stay away from testing it.
While it’s good to store your weed in a humidity controlled environment, too much humidity can grow mold and that’s a very bad thing. Don’t smoke spongy or moldy weed!
If you want to get really technical with it, the United Nations Office on Drugs and Crime has outlined this super hand guide for THC potency over time.
- After one year, weed loses roughly 16% of its THC
- Two years in storage results in a loss of 26% of its THC
- Weed loses 34% of its THC after three years.
- After four years in storage, weed loses 41% of its THC
While it may be tempting to try some old buds you found in your ski pants from last year, it’s more than likely that you won’t get high and might be left with a bad taste in your mouth or an uncomfortable cough.
How to Tell if Your Weed is Too Old
If you’re not sure how long the weed in question has been in its hiding place, there are a few distinctive things you can look for to determine if it’s too old to enjoy.
- It doesn’t have any smell and crumbles to dust when touched
- It’s spongy and too damp, likely has mold on it
- It doesn’t have any smell
Overall, keeping your weed fresh is dependant on how it’s stored and where. It won’t kill you to smoke dry, dusty weed but it also won’t do much for you so it’s best to just toss it. Sorry. On the other hand, it’s definitely not good to smoke old weed that is spongy or moldy. This can make you super sick.
Flower isn’t the only form of weed that can go bad. Edibles, concentrates, and vape pens are also all subject to time and the breaking down of cannabinoids that can rob cannabis of its potency.
How to Keep Weed Fresh Longer
In addition to that rad list of containers and storage solutions from High Times there are some tried and true techniques to keep all your cannabis nice and fresh. You’ll still need to plan on consuming it within a year, but that’s a nice stretch that is easy enough to work with.
How to Keep Flower Fresh
Store in an airtight or vacuum-sealed container to keep air out and keep in anything that is emanating from the flower. Keep it in a cool, dry, dark place to keep it away from light damage, temperature fluctuations, or too much humidity.
How to Keep Edibles Fresh
Keep them in their original packaging in a cool, dry place. Hard candies and gummies can easily melt, and the refrigerator is the best bet for many types of edibles.
How to Keep Concentrates Fresh
Keeping concentrates in silicone will not only keep them fresh, but it’ll also be easier to extract them when you’re ready to smoke. Shatter is hard to separate from glass where silicone makes it super easy.
Does weed go bad?
Yes. Proper storage and a year timeframe is your goldilocks zone. Anything beyond that is going to be less potent than desired or even moldy. Inspect your old weed well before you decide to smoke it. And if you want to throw it away, come into The Spot 420 to reup on some of the dankest buds around.
How long does weed stay fresh? To keep weed fresh there are some basic storage needs you’ll need to consider. Humidity control, airtight or vacuum seal…