Ask Cheri

Can I Use OLD Marijuana for Cooking? Does It Need Decarbing? 

By Cheri Sicard
December 4, 2019

Dear Cheri,

Can I use old marijuana for cooking?   Does old cannabis need to be decarbed?  I have 12 ounces of 2-year-old trim.  It’s pretty darn dry.   I would like to use it to cook with but I’m worried about burning it during decarbing.  Due to the volume and dryness, what would you suggest?

Lucky you!  Cooking with old weed that has gotten dry is a great use for it, as is making cannabis topicals.

The process of decarbing is not likely to burn it, regardless of how dry it is.

That said, as old as your plant material is, it is likely already decarbed to a large degree.  Age will also cause decarboxylation, not just heat.  Hopefully, anything that has not decarbed due to age will decarb during the process of making your infusions such as marijuana butter or marijuana oil and in the process of cooking your recipes.

A disadvantage of older plant material is that many or all of their delicate terpenes are gone or seriously degraded.  But many of these would burn off during cooking even with fresher cannabis.  And even without the benefit of terpenes, you can still make some mighty potent edibles.

Over time the THC in cannabis will convert to CBN.  At 2 years old this conversion is likely only partial.  If your cannabis is more than 4 years old all of the THC may have become CBN.  That’s OK, use it anyway and you will be rewarded with edibles that will be especially useful for helping you fall and stay asleep.  CBN is also anti-inflammatory and can help reduce pain, among other health benefits.  Likewise depending on why you are making edibles, cooking with older plant material can be beneficial and therapeutic.

So, to circle back to your original question, if it were me in this instance I would probably cook with it as is without first decarbing.

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About the author

Cheri Sicard is the author of Mary Jane: The Complete Marijuana Handbook for Women, and The Easy Cannabis Cookbook.  Her online courses at have educated 1000s of students about marijuana, cannabis cooking for home cooks, and making infused topicals.

  • Hi Cheri
    Thanks for using my question about old trim, I also asked you a few days later about using ghee. I’d like to report really good results. The trim was very high grade and not having to do anything extra made for a very easy session. But my favorite part was using the ghee, I was never happy with whole butter because of all the milk fat and other yucky stuff that had to be washed away, what else is getting washed away ? Ghee is super clean [as you know]. Great experience, thanks.

  • I have a male volunteer in my garden. what can I do with it. Friends have said it would be good for baking. It should have good genetics since this is where I have emptied my cleanings for years.

    • I would not use it for baking as it will not be potent.  You can if you choose, but I think it is a  waste.


It is nutritious though.  Juice it (you will need a wheatgrass type juicer), use the leaves in salads, etc.  If I were going to make an infusion I would try it in topicals before edibles, but either way, the potency is going to be way low, so for male plants I usually juice those leaves, keep extra in ice cube trays in the freezer, and I put a shot or so in when making smoothies for a super potent boost of antioxidants and nutrition.

  • Oh I forgot to ask my question I have a air fryer only and I have some ghee oil and shake
    Easy steps to make butter no fail method please I’ve never done this so please simple

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