Article by Leaf News
Dear Herb: A friend gifted me some hash approximately six months ago, and it went missing.
I was recently cleaning out my things after a camping trip and found the hash at the bottom of my backpack. Is it still safe to consume? Will it have lost its potency? — Forgetful Stoner, St. Boniface
Dear Oublieux: Thanks for writing in, and congratulations on your reunion with your long-lost cannabis concentrate. Let’s begin with the issue of potency.
We know that THC degrades over time into a less-psychoactive cannabinoid called cannabinol (CBN), causing cannabis to lose its psychoactive potential. The exact rate of degradation depends on a variety of factors, including ambient temperature and humidity, oxygen exposure, and light or darkness.
The earliest published research I can find on the topic dates to 1969, when a researcher with the U.S. Customs Laboratory tested three different “marihuana” samples that were kept at room temperature for a month, as well as a sample of Colombian cannabis that had been sitting at room temperature for more than five years. She determined that the THC in her samples degraded at a monthly rate of between three and five per cent. Later research reports lower rates of THC degradation in cannabis samples stored in glass jars, with a 1973 study reporting annual degradation rates ranging from 3.8 per cent when stored in a freezer to 6.9 per cent when stored at room temperature. Either way, scientists agree: THC doesn’t last forever.
Contemporary research has tested how different forms of cannabis degrade under different conditions, and a group of Italian scientists published a paper on the topic earlier this year. The researchers took six different cannabis samples — three bud samples and three hashish samples — and stored them under a variety of different conditions for four years. They tested the samples every 100 days.
As they expected, the Italian researchers found that the THC in both the cannabis bud and the concentrated hash degraded over time. In the samples stored at room temperature, the researchers wrote, “almost 100% of THC was degraded after four years.” Samples kept at a cooler temperature degraded more slowly. (That doesn’t necessarily mean it’s a great idea to freeze your cannabis, as I discussed in this previous Dear Herb.)
I don’t know exactly how your hash was stored in your backpack, and it’s impossible for me to say exactly how much THC you lost while your hash sat forgotten, but its safe to say that it’s less potent than it was six months ago. If the hash was sealed in a container of some kind, it almost certainly fared better during its half-year staycation.