Found some weed you forgot about? We've all been there. Before you toss it, learn how long it lasts, if you can still smoke it, and what to do with old weed.
Does weed expire?
Eventually, yes, cannabis expires. But if you store it properly, flower can be kept for up to two years.
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After that, it begins a significant decline in quality, potency, and flavor, but as long as it isn't moldy, it may still be safe to smoke. However, the experience may be unpleasant depending on how dry the buds are.
How to check for old weed
Before putting that old nug you found in your couch cushion to the test, check for these signs to determine if it's safe to consume.
Dull or moldy appearance
Discoloration is one of the clearest signs of geriatric weed. Fresh flower has a vibrant green hue with frosty trichomes and maybe some orange or purple hues, while old weed looks brown or grayish.
If the buds show any signs of mold or mildew, they'll usually have white or grayish spots, a powdery appearance, fuzzy or web-like growth, or a musty, unpleasant odor. The last thing you want to do is smoke moldy weed.
Dark and withered trichomes
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You can use a jeweler's loupe to see if the trichomes on the surface of the buds are clear, milky, or amber. You're good to go if they look like any of those colors. The weed is probably past its prime if they are dark or appear damaged.
Hay or mildewy smell
All freshly cured flower has a distinct, pungent aroma that can be citrusy, piney, or spicy. If your weed smells musty, moldy, or like hay, it's almost certainly too degraded to use.
Dry and brittle feel
Old weed typically crumbles easily when touched. Freshly cured weed has some stickiness and bounce to it.
Type of storage used
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Observe the packaging and storage conditions. If the weed was not stored properly in an airtight container in a cool, dark place, it's more likely to have aged poorly.
Harsh smoke
If everything checks out and you decide to light up your old weed, you might experience a harsh smoke. Maybe the weed didn't look bad initially, but if the smoke is rough on your throat and lungs, it's a good indication the weed is too old, and you should switch it with fresher cannabis.
Can you smoke old weed? Is it safe?
Smoking old weed is usually not a serious health hazard unless it's moldy. If it's not moldy but just dried out, it's likely still safe to smoke, but don't expect it to be as effective as it was when it was fresh.
What happens if you smoke old weed?
There are a few things that might happen if you smoke old weed:
- Potentially nothing: If the cannabinoids have degraded completely, but the flower itself hasn't gotten moldy, you might not notice any effects. If anything, you'll experience a rough smoking experience without any of the joys of a psychoactive high.
- A mild, stale high: Old weed can still get you high, but it's likely to have lost potency and its distinctive aromatic properties since its cannabinoid, terpene, and flavonoid content decrease over time. Cannabis loses about 17% of its THC content after one year and continues losing it after that.
- Some health consequences: Smoking overly dry weed might be uncomfortable but fine if you don't do it often. If your weed is moldy, however, you could be looking at some unintended health consequences from smoking it, as inhaling mold spores can irritate the respiratory system, trigger an allergic reaction, or, in severe cases, lead to a lung infection. Avoid smoking moldy weed at all costs.
What to do with old weed
Since old weed lacks moisture, flavor, and potency, it may not make for the most pleasant smoking experience. Fortunately, all hope is not lost — other enjoyable uses for old weed can salvage the plant's remaining psychoactive compounds:
Vape it
By vaping old weed, you can inhale what's left of the plant's psychoactive compounds. Since smoking cannabis inevitably burns off valuable cannabinoid content, using a dry-herb vaporizer may be a more efficient way to consume it.
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Remember that the terpene profile in old weed is lower, meaning it won't taste as flavorful. Otherwise, vaping is a convenient, controlled, and discreet way of consuming old cannabis.
Turn it into edibles
Cooking with cannabis is always an option, and perhaps an even better one when you've got old weed you're unsure how to use. Turning it into edibles may help you get a little more potency from its psychoactive ingredients by using the second-pass effect to produce stronger, longer-lasting effects.
The second-pass effect happens when digested THC metabolizes into a compound called 11-Hydroxy-THC. This form of THC is more efficient at crossing the blood-brain barrier and generally produces more potent effects than the delta-9 THC we all know and love.
Turn it into kief
One handy use for old weed is to turn it into kief, a dry, solventless cannabis concentrate that contains more cannabinoids, terpenes, and flavonoids than whole buds. Kief, also known as dry sift, refers to the loose trichomes that separate from ground cannabis flower.
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Trichomes house the highest concentration of cannabinoids, including THC, in the cannabis plant. When extracted, this concentrated form of weed can produce powerfully potent effects. The easiest way to turn your old weed into kief is by using a dry herb grinder to sift the dry flower through a series of screens. It can then be sprinkled on top of a bowl or added to a joint and smoked.
Make other concentrates
For the truly dedicated cannabis lover, it's possible to concoct even stronger homemade concentrates like bubble hash and infused tinctures from old weed. Concentrates maximize potential therapeutic benefits due to their potency, and you can consume them in various ways.
Rehydrate it
Cannabis loses moisture over time, becoming extremely dehydrated with age. To give old weed some life again, you can reintroduce moisture into its environment in a few ways:
- Humidity packs: You can use salt-based control sachets called humidity packs, sold in most licensed dispensaries. Simply add the sachet in with your weed and change as needed.
- Citrus peels: Adding a fruit peel with your old weed does a great job of transferring moisture and citrusy flavors to your otherwise flavorless bud. Leave the peel in with your weed for no longer than 24 hours to avoid over-humidifying the container, which can increase the chances of mold.
- Damp cotton ball: Place a wet cotton swab, cotton ball, or similar product into your container of old weed to rehydrate it, but be careful not to let it directly touch the buds. Like humidity packs, this method will slowly reintroduce moisture back into your old weed's environment.
Make a topical preparation
If you don't want to inhale or ingest old weed, one way to still use it is to make a topical preparation that can be applied to achy joints and stiff necks and backs.
Bottom line
As long as your old weed isn't moldy or off-putting, you can put it to use in some way or other. It may not be the best experience, but there's a chance you can still get some benefits from it.
FAQ
How long does weed stay good?
Weed's shelf life depends on how it was cured and stored, but generally, it can last up to two years. When stored correctly in an airtight container in a cool, dark place with stable humidity levels, you can maintain its quality and potency for an extended period. If your weed doesn't become moldy, you can safely enjoy it some months or even years after purchase.
Does weed lose potency over time?
Yes, weed loses potency as the cannabinoids — mainly THC — degrade. The rate of potency loss depends on factors like the storage temperature, humidity, and exposure to light and oxygen. No matter how well you store your weed, you can expect some loss of potency over time, but store it properly, and it can still be relatively potent for months.
Does weed get stale?
Yes, weed can get stale — especially if it's exposed to heat or not stored in an airtight container. While this may affect the overall experience, it doesn't necessarily make the weed unsafe to consume. Carefully inspect it with a jeweler's loupe to ensure it isn't moldy before smoking it.
This article was reviewed by Bonni Goldstein, MD, a physician specializing in cannabis medicine in Los Angeles, California, owner and medical director of CannaCenters, and medical advisor to Weedmaps.com.
