Does Weed Expire? How to Tell When Cannabis Goes Bad

by Haley Mills · December 14, 2022

Weed expires eventually, but it depends on how you store it. Learn the best ways to keep your weed fresh for when you need it.

selective closeup of dry cannabis on a white surface

Weed expires eventually, but it depends on how you store it. Learn the best ways to keep your weed fresh for when you need it.

All marijuana has a shelf life, just as fruits, veggies, herbs, and other plant products have an expiration date. Thankfully, your cannabis shelf life typically lasts at least a year if you store it in an airtight container in a cool, dark environment to avoid direct sunlight. While older cannabis usually won’t hurt you, it will lose its freshness, potency, and flavor over time. It may still get you buzzed, but older buds will never provide the same effects as freshly cured marijuana.

Guide to Marijuana Shelf Life

Below, we’ll cover the shelf life of a few of the top weed consumption methods.

Flower

Dried cannabis flower can be viable for six to twelve months depending on how and where it is stored and how the cannabis plant was cured.

Edibles

Most cannabis edibles issued from licensed dispensaries will have an expiration date, but you can follow this rule of thumb for two popular types of edibles:

  • gummies- will start to lose potency after three months; they can be stored in the freezer for six months
  •  brownies- two weeks in a sealed container; six months in the freezer

Concentrates/ Tincture

Concentrates and marijuana wax can be placed in the freezer to maintain freshness. Wax can typically last up to six months and cannabis oil can last up to a year when stored properly.

Topicals

Topicals can last up to a year or more, they are by far the longest-lasting cannabinoid product, but they can still lose potency and effect over time.

How Long Do Cannabinoids Last

In optimal conditions, adequately stored cannabinoids can last six months to a year. The general rule of thumb to consume cannabis while it still has its flavor and potency is to use it within six months.

Some studies show that weed loses its strength after approximately one year: 

  • 16 percent THC lost in one year
  •  26 percent THC loss in two years
  •  34 percent THC loss in three years
  •  41 percent THC loss at four years

How Can I Tell if my Cannabis is Old?

You’ll want to check a few key points before indulging if you find old weed and don’t know how long it’s been in storage. Older, dried-out weed will easily break apart into a fine powder. Mold can grow over trichomes and looks like a collection of white powder on the top of the buds. You can also locate mold when you break them apart.

Terpenes don’t keep on improperly stored weed. So, if your weed has a pleasant scent, it’s probably acceptable for consumption. Look out for marijuana with a mildew smell, which is a vital sign of mold growth.

Marijuana that is recently cured and dried will make a snapping sound when you break it apart, whereas old weed will practically crumble in your hands.

temperature

The best temperature for cannabinoid storage is around 70° Fahrenheit or below.

humidity

Relative humidity levels should stay between 55 and 65 percent.

air

Airtight container storage protects terpenes from oxidation, which causes them to deteriorate and evaporate.

light

UV light and subsequent heat degrade and synthesize cannabis, converting THC into CBN, a sleep-inducing cannabinoid.

The Basics of Cannabis Mold

Terpenes don’t keep on improperly stored weed. So, if your weed has a fresh, pleasant scent, it’s probably acceptable for consumption. Look out for marijuana with a mildew smell, which is a vital sign of mold growth. As the buds age, mold can grow over trichomes and looks like a collection of white powder on the top of the buds. You can also locate mold when you break them apart. While smoking moldy weed may not kill you, it is not recommended and could have potential adverse effects, especially for those with certain chronic health conditions.

Three Most Common Types of Bud Mold:

Bud rot usually begins with fluffy white growth in the middle or on the sides of your buds. It is easy to see with the naked eye as the color changes and becomes a dry weed texture. 

Powdery mildew looks like small circles of white mold on the tops of stems and leaves. As the fungi progress, they will become denser, covering the buds in thick white powder.

Aspergillus is a common mold that is found both indoors and outside. Generally dark green-black, Aspergillus mold spores create a lung infection after inhaling and can be found in the soil or cannabis buds.

Storage Tips

One of the vital steps to properly store cannabis is using good quality, airtight storage containers. Glass mason jars with a tight seal are ideal for protecting your buds from humidity, parasites, climate issues, and mold. There are also glass jars available with a UV-proof finish or a violet/dark brown tint to protect your weed from the light. Humidity packs can help ensure humidity levels remain ideal for storing buds to keep the weed fresh. Plastic bags risk drying and losing the potency of your cured cannabis.

There are multiple ways to store marijuana edibles; however, it greatly depends on the type of edible. For cannabis brownies, it’s best to keep edibles with wax paper in airtight silicone containers. If you plan to freeze edibles, cover them in plastic wrap and place them in sealed, zip-up plastic bags for best results. These will maintain their full potency for about two months when stored properly and can successfully be stored for up to six months.

When storing cannabis gummies, they typically last up to a year without being frozen, but the potency will decrease over time. If you are going to keep gummy edibles, wrap them up and place them in an airtight container before deep freezing them for the best results.

With medical marijuana tinctures, it’s best to keep them in glass jars at room temperature in a dark place. Storing like this will keep it fresh for a few months. While you can freeze tincture in airtight containers, it doesn’t maintain the oil’s integrity.

FAQs: Shelf Life of Weed

Do edibles lose potency over time?

Yes. Most edibles have a fairly short shelf life because they contain food ingredients. It’s important to follow accurate guidelines about storing edibles.

Should I store fresh weed in a plastic bag?

You can, but it’s not recommended. Plastic bags risk drying and losing the potency of your fresh cannabis products.

Will topicals go bad as quickly as cannabis flower?

Topicals last longer than most cannabinoid products. When stored in a dry, cool place they can even last over a year.

Why is Storing Cannabis so Important?

If you’re concerned about maintaining the potency and flavor of your weed, you’ll want to educate yourself about proper storage. First, it’s essential to remember to store any cannabis products away from children and pets. 

Next, cannabis degrades quickly, and although there’s no official expiration date when properly cured and stored, loose dry buds can last from six to eight months after harvest, and pre-rolled joints can last about three months on average.

Third, when weed is exposed to excessive heat or light, it can dry out and turn into CBN, making it harsh, difficult to smoke, and extremely sedative. 

Storing weed correctly means preserving the cannabinoids and terpenes to keep your flower fresh. Cannabinoids like THC and CBD deliver the desired effects of cannabis, and terpenes provide flavor and aromatics. Both cannabinoids and terpenes deteriorate with time and exposure to elements like heat, oxygen, and UV rays. 

The Journal of Pharmacy and Pharmacology published research in the 1970s showing that you can keep cannabis stored for up to two years if it is correctly cured for at least four weeks and kept in a controlled environment. Extreme heat, cold, or humidity can cause the buds to develop mold or mildew.

Conclusion

We’ve learned that cannabis storage is essential for maintaining flavor, potency, and overall cannabinoid integrity. It’s recommended that your fresh cannabis is stored in a cool, dark environment in an airtight, sealed container. Following these tips can lower the risk of degradation and avoids exposure to extreme elements that can wreak havoc on the terpenes and cannabinoids.

Last Updated: January 30, 2024

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