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What you will learn in this post:
Weed doesn't last forever. Just like everything else, it has a shelf life.
Even so, that doesn't mean cannabis goes bad or expires like other consumable products such as milk. As a matter of fact, if stored properly, weed can last quite a long time.
In this article, we discuss the expiration dates of cannabis, how to tell if your flower has gone bad, and how to prolong its shelf life.
Does Weed Expire?
Sort of.
It doesn't "expire" in the sense that dairy or produce does: cannabis doesn’t become unsafe simply because it’s past its expiration date. But it does lose its potency and degrade in quality over time. And past a certain point, the loss of flavor and quality can change the potency, effects, and enjoyment you get from the product.
Generally speaking, weed's "expiration date" is roughly one year after it’s purchased. Past this point, it may become dry, taste musty, and lose the psychoactive effects you were seeking when you made the purchase.
While most consumers with “expired” weed are left with dried out flower (that can often be rehydrated), it is possible for old cannabis to become too moist.
Fresh marijuana contains some moisture within the buds. You've probably already noticed that fresh nugs are a little squishy and sticky to the touch. However, this hallmark of high-quality bud makes improperly stored cannabis susceptible to developing mold or other pathogens that are unsafe to consume and could lead to health problems such as headaches, vomiting, diarrhea, or even lung infections.
While moist weed left for long periods is more likely to start growing mold, unfortunately, this mold can start developing at any time if the conditions are right. It doesn't have to be past weed's "expiration date" to do so. As such, you should always check your weed for mold, even if you just recently purchased it from a dispensary.
So how long does cannabis last?
Beyond the potential for mold in moist flower, marijuana doesn't expire like other food or consumable plant products. It'd be more apt to say that weed eventually becomes stale, like a potato chip.
Sure, you can eat a stale chip, but you don't really want to, nor will it be all that enjoyable. The same goes for smoking stale weed.
What Happens When Weed Expires?
By and large, the main thing that happens when weed expires is a loss of smell and a harsher or mustier taste.
In most instances, old cannabis will still be psychoactive. But THC degrades to CBN over time, meaning the longer you wait to smoke your flower, the more THC you lose. Typically, it's best to consume cannabis within 3 - 6 months. After this, the concentration of THC begins to diminish.
According to research conducted by the United Nations, cannabis loses approximately:
- 16 percent of THC after 1 year,
- 26 percent of THC after 2 years,
- 34 percent of THC after 3 years,
- 41 percent of THC after 4 years,
So, how can you tell if your cannabis flower is past it’s unofficial expiration date?
How to Tell if Weed is Bad
Fortunately, it's relatively easy to notice when cannabis has expired. Here are the main things to look out for:
Change in Aroma
One of the most immediate ways to tell if weed has gone bad is if the aroma has changed (or even vanished entirely).
Freshly cured marijuana offers a very distinct smell: depending on the strain, you may smell skunk or diesel or cheese. However, the aroma of expired weed can be severely diminished, it may become musty, or it could all but vanish.
Change in Texture
Along with the change in smell, the texture of the weed is another giveaway that it is past its prime.
Freshly cured marijuana will feel sticky and have a little give to it. You'll be able to break and pull it apart. Expired weed, however, will be dry and dusty, to the point that it may crumble when you press on it or try to break it apart.
While overly dry cannabis can still be smoked (albeit with a less pleasant aroma and flavor), moldy weed should not be consumed. Doing so can put you at risk of becoming sick or developing severe medical complications such as lung infections.
Change in Taste
Like its aroma, marijuana has a distinct and well loved flavor profile when it is consumed or smoked. The same cannot be said of expired weed, though. As the flower dries out, the flavor can be lost. And the lack of moisture can result in a harsh taste and increased throat irritation.
Mold Has Developed
Finally, the most important thing to look out for that'll mean the weed has gone bad is the presence of mold. In most cases, you'll observe mold as any oddly discolored spot or white fuzz on or within the cannabis flower.
How to Check for Weed Mold
Unfortunately, checking for mold on cannabis isn't always easy. It requires some care and attention to detail: we walk through the process in our article on All You Need to Know About Moldy Weed.
Several different types of mold grow on marijuana, with the most common being Powdery Mildew and Botrytis Blight (Gray Mold), which causes bud rot. As the name suggests, Powdery Mildew will look like white powder or fuzz on your marijuana.
No matter which mold has infected your cannabis, or when you purchased the flower, the presence of mold can make the product unsafe to consume. In fact, a UC California, Davis study found bacteria and mold on 20 cannabis samples that were recently bought from dispensaries. So it's always best to look closely every time you stop by the dispensary.
How to Stop Weed from Expiring
There are several ways you can preserve weed and prevent mold development for longer. While it isn’t possible to preserve your flower indefinitely, here's how you can properly store your weed to extend its shelf life:
✔ Store Cannabis in an Airtight Container
Plastic bags and open containers allow oxygen and light to reach your flower, increasing the rate at which it dries out.
By storing your marijuana flower in a glass container with an airtight seal – like a mason jar – you give your stash the best chance of lasting 6-12 months or longer.
Luckily, these kinds of containers are cheap and easy to find. You may even find options available at your local dispensary.
✔ Pay Attention to Humidity
Like excess oxygen, too much humidity will wreak havoc on the quality of your bud.
The ideal range you should shoot for is between 59 and 63% humidity. Above 63%, your cannabis will be too moist, creating an environment that allows mold spores and bacteria to thrive. Below this range, your weed will dry out faster, shortening its shelf life.
Fortunately, there are many products that can help you control the humidity in your cannabis containers. Specifically, weed humidity packs and humidors.
✔ Store Cannabis in a Cool, Dry, and Dark Place
Our last tip – and arguably the most important – to help you preserve your weed is to keep your airtight container in a cool, dry, and dark place.
Excess temperature, moisture, and light can all shorten the shelf-life of your cannabis.
Keeping cannabis within direct sunlight for too long will cause it to quickly lose its potency. In fact, research has been conducted that showed a 0.5% decrease in THC every hour cannabis flower was exposed to direct sunlight.
Excess temperature, especially when combined with excess moisture, will make it easier for mold to grow on your weed. However, this doesn't mean you should store your cannabis where it’s too cold, either. Placing your marijuana flower in a fridge, freezer, or other area that’s too cold can dry out the flower faster, resulting in a loss of flavor and potency.
The ideal temperature range when storing your cannabis is between 60 - 68 degrees F.
Conclusion
Cannabis doesn’t expire in the traditional sense, but if you have flower that is more than 6-12 months old, you may begin to notice a loss of flavor, aroma, and potency. And too much moisture can leave you with moldy marijuana that is best avoided.
The surest way to keep your cannabis fresh is to employ proper storage methods, and to enjoy it sooner rather than later.
The information in this article and any included images or charts are for educational purposes only. This information is neither a substitute for, nor does it replace, professional legal advice or medical advice, diagnosis, or treatment. If you have any concerns or questions about laws, regulations, or your health, you should always consult with an attorney, physician or other licensed professional.
