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The CULTA Blog

Everything You Need to Know to Keep Your Medical Cannabis Fresh


If you have a stash of medical cannabis that you haven’t used in a while, you’ve probably noticed that the buds get drier over time. Although medical cannabis packaging has become more sophisticated and usually includes a harvest date and third-party testing results, one thing still seems to be missing: a clear expiration date. When stored properly, medical cannabis can maintain its freshness for up to two years (!!!), but there are a lot of contributing factors to how long your cannabis will stay fresh, including light, air, and temperature. 

In this article, we’ll provide some tips on how to keep your medical cannabis fresher for longer.

What happens when cannabis gets old?

Unlike food or other medications, consuming medical cannabis that’s old or past its prime won’t harm you. You won’t get sick, but your medicine won’t be as effective as it would be if it was properly stored. Before we dive into proper storage, we want to give you a quick breakdown of what exactly happens when your medical cannabis starts to age: 

  • Lost THC- As cannabis is exposed to heat, oxygen, and light, the cannabinoids (including THC) will break down. It won’t render the cannabis completely ineffective, but you’ll notice a difference in its effectiveness over time. 
  • Lost flavor- Over time, medical cannabis will taste and feel harsher upon smoking. This is the result of the terpenes drying out over time and is caused by exposing your cannabis to excessive light and heat. 
  • CBN conversion- As THC breaks down, it doesn’t just disappear into thin air. It’s actually converted into another cannabinoid called CBN. CBN certainly won’t harm you, but it won’t affect you the same way THC does. 

The main causes of cannabis aging come down to humidity, temperature, light, and container materials, and we’ll dive into each of these more in-depth below. 

Glass > metal and plastic

When it comes to storing cannabis, what type of container you use is important. While plastic and metal jars can be used in the short-term (such as when transporting your cannabis from the dispensary back home), they don’t make great long-term options. Metal and plastic can impact the flavor of your medical cannabis over time, and the static charge found in plastic containers can actually cause trichomes to fall off the buds and stick to the sides of the container. 

Fortunately, the best glass jar for storing cannabis is also one of the most popular glass jars in existence: a Mason jar. You can purchase a Mason jar at virtually any store (Amazon even sells them in bulk!); just make sure that the seal is super tight. And remember, glass jars will protect your medical cannabis from oxygen and humidity, but you’ll still have to make an effort to protect it from light (more on that later.)

Maintain a cool temp

High temperatures can cause your medicine to dry out (and promote the growth of mildew and mold), but freezing temperatures aren’t good for it, either. Avoid storing your medical cannabis near a heater, radiator, or near kitchen appliances. The ideal temperature for cannabis storage is between 60-70 degrees Fahrenheit, so if you’re comfortable in your environment, your cannabis will be, too. 

Some medical cannabis users freeze their cannabis or keep it in the refrigerator. These are both no-no’s, at least for flower. (Some edibles can be stored in the refrigerator; always read the packaging!) Freezing cannabis can cause the trichomes to fall off of the plant, and the constant temperature fluctuations caused by opening and closing your fridge can make your medical cannabis grow mold. Yuck! 

Keep it dark

Do you want to know why so many packaged and canned goods say “store in a cool, dark place” on the label? A cool, dark environment is ideal for food preservation, and it can help preserve your medicine, too. A 1976 study published in the Journal of Pharmacy and Pharmacology actually concluded that light is the single biggest contributing factor to the loss and deterioration of cannabinoids, so this is one recommendation that should not be ignored. 

If you’re able to get your hands on an opaque or brown Mason jar, that would be the best-case scenario. Otherwise, using a clear Mason jar and storing your cannabis in a closet, cabinet, or dark room is fine.

What about mylar bags?

There’s a reason so many dispensaries use mylar bags: they’re opaque, are effective at keeping out water and air, are durable, and keep the odor in during transport. If you’ve paid attention to this blog, it’s plain to see that mylar bags cross many of these best practices off the list. As an added benefit, the mylar bags you can purchase from a dispensary are child-resistant and tamper-evident and have a zip-locking mechanism that’s easy to use. They block out UV light, keep the product cool, and aren’t made from toxic chemicals. 

Whether you opt to store your medical cannabis in mylar bags or glass Mason jars, both are effective at keeping out heat, moisture, and light. 

Cannabis storage do’s (& don’ts)

Here is a quick rundown of some quick things to avoid when storing your medicine:

  • Don’t store cannabis in plastic bags
  • Don’t freeze cannabis or keep it in the refrigerator
  • Don’t roughly handle cannabis (it’s fragile!)
  • Don’t add any other organic matter to your cannabis jars
  • Don’t expose your cannabis to heat or light 
  • Don’t store your cannabis next to grinders or pipes 

And here are some best practices to keep in mind for the best-tasting, fresh cannabis: 

  • Use an airtight glass jar (opaque is best!) 
  • As you consume your cannabis, move it to smaller storage jars to limit the amount of airspace between buds 
  • Do your best to protect your medicine from heat, light, and moisture 
  • When its time to use your flower, pull out what you need and immediately close the jar 
  • If you’re concerned about the scent, don’t use air fresheners around your cannabis. Instead, keep your cannabis in a scent-proof container like the CULTA x Revelry smell-proof bags.  

Finally, although this won’t impact its taste, always store your medical cannabis in a secure location, especially if children live in your household. 

Start with quality medicine

We hope that you’ve learned how to keep your cannabis fresh in this article. Ultimately, starting off with professionally grown, high-quality medical cannabis is your best bet. Medical cannabis that has been grown, processed, and packaged by a reputable dispensary is already fresher and of higher-quality than other cannabis. To purchase the highest quality cannabis in Maryland, head to our Federal Hill dispensary today.