As the title says, how do you know if you’ve had your terps long enough to go bad? I have terpene isolates that I bought in big bottles a while back. There’s a couple that taste slightly different than they used to. Maybe I became a snob with more access to cannabis terpenes so coming back to these terps is like jumping into the pool after a hot tub.
So my question is do terpenes go bad and how can you tell? I’m going to buy more isolates and compare but apart from that. Also, how long do they even last?
Terpenes are volatile and some degradation occurs at room temp, so you could expect changing characteristics over time, yes. They also oxidize further changing the composition. But im not certain how long they last or not. I have vials that still smell the same after several, months. I have noticed that some carts lose the taste after sitting for some time and also change taste, so the question is valid.
It’s just that so many people have terpenes but nobody has talked about how they go bad or if they even do go bad. They become less good over time but not bad, per se.
If something smells off, it likely is, and a test is the surefire way to tell.
Terpene isolates like myrcene are almost impossible to prevent degradation into non-terp compounds (like acetone) overtime, some of which could cause a failure for residual solvents at the lab. in my experience the levels are low, but it is a feasible given the % some folks add to their carts. I havent tested my now 3yr old can of myrcene this yr to begin creating a curve for degradation…I highly doubt it has stopped degrading, I’ll go give it a smell this eve.
A way to limit degradation is to add a quencher/antioxidant to the bulk isolate, which will need to be safe to vape. There are plenty of candidates present in the plant. Even Isolates stored in a N2 sealed jar in cool, dark env. will see some degradation over time. The challenge becomes more complex as multiple isolates are formulated into a “strain profile”, the mixture could become more or less stable to degradation depending on the mixtures components and ratios. Opportunity exists to create elegant formulations that are stable, and nature is a good guide. The formulated strain profiles are far from complete, and labs are limited to the compounds they test for (for now).
Carotene is a good quencher…will add yellow/orange pigment, but read today in a veg oil purification book that it is often re-add to ensure oxidation is offset.
Which isolates? Some isolates are of greater purity than others. The lower purity isolates may be more likely to change over time. Humulune comes to mind in terms of purity, at around 55-65% generally, with the other 35-45% of ‘stuff’ comprised of other terpenes. But in my experience isolates don’t change enough over time to notice it through aroma (under preferred storage conditions).
Most isolates are ‘good’ for at least 720 days after production, but others are good for at least 360 days. Improperly stored terpene blends seem to be more subject to change than isolates.
To know for sure you could use possibly use refractive index measurement (has it changed?), but GC would be better (has it changed, and how has it changed?).
I suspect the change over time for carts is caused by many factors, not least of which being photooxidation (I think darkened carts make a lot of sense).
For this industry storing at 65-70’F, in the dark, and opening as few times as possible (with short open times when the cap is removed) is generally sufficient. Cold storage is great when it’s practical, but it’s also not really necessary for terpene blends. A potential issue with cold storage is the possibility of condensation within the bottle in a warm and humid room, especially if the bottle is only partly filled (has a lot of head space).
Thanks for this reply! My caryophyllene leaves me with a strong taste that I never remember being there. The cap broke so I’m assuming that my parafilm capping wasn’t sufficient. I ordered a new bottle and am waiting on my gc to be up and running from maintenance before I get an update on if my terps actually did spoil.
I have cannabis derived terps in the fridge And some just in a cupboard for months. And they don’t seem much different Now that’s not a lab test , I’m just saying I don’t notice much difference in 6 months
I suspect some may gum up in time.The C10’s will leak out. Oxidation is possible too. Bad needs to be defined specifically to product requirement. Short answer, yep.