Can Weed Expire in a Jar?

You may be curious to know if weed can expire in a jar and, if so, how to extend its shelf life. Cannabis degrades over time like other natural products. The degradation process affects its potency, flavor, and overall quality.

Proper storage is crucial to preserving cannabis’s unique characteristics. Understanding the factors that influence the longevity of cannabis—and choosing the best storage containers—ensures you'll always enjoy your cannabis at its peak.

1. THC Degrades Over Time, Even When Stored in a Jar

THC (the primary psychoactive compound in cannabis) degrades over time. This process occurs faster when cannabis is not stored optimally. 

When THC degrades, the chemical structure of THC molecules transforms into the more sedative and less psychoactive CBN. There can be a noticeable decrease in your buds' potency and psychoactive effects when this occurs.

2. Where You Store the Jar Impacts Degradation

Five main factors affect how quickly cannabis naturally expires: light, air, heat, moisture, and time. Choosing to store your weed in a jar is only the first step because you also need to reduce the jar’s exposure to elements that can harm the product’s quality. 

The environmental factors that impact the quality of your cannabis act in the following ways:

• Light: Direct sunlight or exposure to UV light degrades cannabis over time. 
• Air: Cannabis will break down more quickly when exposed to oxygen. This is why choosing an airtight container is critical for optimal weed storage.
• Heat: Heat degrades strains’ unique terpene profile, leaving you with a less aromatic product. Heat also contributes to the breakdown of THC. One study revealed that fresh cannabis flower stored at room temperature lost 16.6% of its THC content after a year. This rose to 26.8% after two years. 
• Moisture: Exposure to too much moisture may accelerate the breakdown of THC in cannabis. It also encourages the growth of mold or mildew.
• Time: Just like other organic materials, cannabis will eventually break down over time.

Proper storage methods that minimize exposure to these factors involve storing the jar in a dark, dry, and cool place and consuming it in the first few months. Some people add humidity-regulating packs to the jar to maintain optimal moisture levels.

3. The Best Weed Containers Reduce Exposure

How you store cannabis will have a significant impact on how quickly it expires. Look for containers that minimize your weed's exposure to the environmental factors that degrade it and cause it to lose quality.

POP VAC Jars

POP VAC jars are a perfect choice for preserving the quality of your cannabis concentrates or cannabis flower. POP VAC jars ensure unparalleled freshness by providing an airtight seal that "pops" every time you open or seal the jar. The sound lets you know your concentrates or flower are in the best possible environment to stay as fresh as the day they were stored. Their opaque design options also protect your flower and concentrates from light exposure.

POP VAC jars are made with food-grade parts that offer a hygienic place to store your products. Unlike makeshift storage options like regular glass jars, they have a built-in child-resistant mechanism to keep children—and your product—safe.

Glass Mason Jars

Airtight mason jars offer a solid option for storing weed. However, they don't offer vacuum sealing capabilities that minimize your products' exposure to oxygen. They also don’t feature child-resistant technology.

Top tip: Avoid leaving too much headspace in the jar as this exposes the product to oxygen. Ideally, you want to leave very little space between the lid and the product.

Choose Glass Containers over Plastic

A 2022 study compared THC-containing blood samples stored in glass and plastic vials at -20ºC (-4ºF) for 4-24 weeks. The study sought to show if there was a possibility of drug adsorptive loss into the container. 

It was found that the samples kept in plastic containers lost 60-100% of their THC concentration while a 30-50% smaller loss was recorded in the glass vials. This suggests glass recipients will be more effective in retaining the potency of cannabinoids than plastic.

4. Use Different Containers for Different Weed Products

How long cannabis retains its quality also depends on the storage requirements for different cannabis products (flower or concentrate, for example). Anecdotal evidence suggests that cannabis flower can maintain its quality for six months or even up to a year if you store the jar in cool, dark, and dry conditions. These conditions will be optimized by choosing a jar specifically designed to store cannabis flower.

Research shows that some herbal and resin cannabis concentrates may remain stable for up to two years if stored in dark, cool conditions. More volatile concentrates should be stored in special containers in a cold environment. For example, it’s best to store bubble hash in a POP VAC jar in the fridge or freezer.

5. The Right Jar Preserves Flavor and Aroma

Cannabis enthusiasts understand that consuming cannabis is much more than just getting high. Cannabis's huge appeal also lies in the range of different flavors, aromas, and experiences it offers. Keeping your weed fresh by keeping your airtight jar cool and away from heat, moisture, and light also protects the product's flavor and aroma.

IMPORTANT: Keep in mind that "airtight" does not mean "smell proof".

6. Medical Marijuana Loses Potency If Stored Improperly 

Many patients in MMJ-friendly states are turning to medical marijuana to relieve symptoms associated with conditions like cancer or chronic pain. Studies have shown THC to be effective in treating certain conditions both in isolation and when coupled with CBD. Research suggests THC could be effective in treating chronic neuropathic pain and fibromyalgia, for example.

Maintaining the THC content of your cannabis products by storing them properly in airtight jars is vital for MMJ patients to retain their medicinal properties. MMJ patients should prioritize quality storage solutions to make the most out of their products and gain maximum relief.

7. Good Storage Practices Prevent Mold Growth

Old weed will generally be safe for consumption even though its taste, aroma, and effects may be diminished. However, moldy weed is harmful to your health. Check for mold spores before consuming your product if you live in a humid location to ensure its safety and quality. This is generally not an issue in places like Colorado that have a dry climate.

Reduce the risk of your weed going moldy in its jar by following good storage practices:

• Temperatures of 77ºF-86ºF are perfect for mold to thrive. Keep your weed jar in cool, dry conditions that don’t promote mold growth.
• Make sure your jar is completely clean and dry before transferring your weed.
• Fill your jars as much as possible to limit exposure to air.
• Make sure your weed is properly dried before storing it.

Proper Storage Keeps Your Cannabis Fresh Longer

Storing your weed in a regular jar will give it a certain amount of protection against damaging environmental factors. However, specialized opaque jars with vacuum seals provide more protection and slow the degradation of your weed.

When deciding how to store cannabis, choose a container that keeps your products fresh for as long as possible. Talk to our sales team and buy our POP VAC jars for a solution with a vacuum seal and an opaque design that minimize exposure to light and oxygen for best results.