How strong are my weed brownies?

Getting the right answers in your cannabis journey can be tricky. But with The Cannigma’s Ask the Expert, you can find questions from readers like you, answered by a real cannabis pharmacist.

Question: Just a quick question about using cannabis in fudge or brownies. The package says the flower is 34.75% THC. I used 1/2 oz, and they seem pretty potent. How do you tell what the potency is? Is there a formula for that?

Answer:

This is a common and kinda complicated home edibles math question, but we got you. The truth is that without an analytical device, you can only estimate the potency of your brownies – you’re not going to get an exact figure. Here’s how we at The Cannigma would do the math you’re asking about, and this is also how we programmed our new calculator (hint: use this!!).

Note that I rounded 34.75 up to 35% for simple math.

35% THC means 350mg THC per gram of weed;
You used 14 grams of cannabis (1/2 ounce);
14g x 350mg/g = 4,900 mg THC total in all of your herb;
You can extract this 4,900mg into any amount of oil/butter, let’s say 500ml (~2 cups) ;
4,900mg / 500mL = 9.8mg/mL; (note: assuming your extraction was perfect!)
Our calculator assumes a 20% loss of potency during the extraction process.
9.8mg/mL x 0.8 (to account for loss) = 7.8mg/mL THC

So, that’s the concentration of your oil. Now let’s take it down to the brownie level to answer your question. Let’s assume that your recipe called for 1 cup of that infused oil (240mL), and that you’re making 16 brownies.

240mL x 7.8mg/mL THC = 1,872mg THC in the total batch
1,872mg THC / 16 servings = 117mg THC per serving

If this was your recipe, they would be quite potent indeed!

I hope that all makes sense. If not, remember we made a tool to do it for you and we’d love to hear if it’s useful. Be in touch!

Thank you and happy baking!

Codi Peterson, PharmD
Scientific advisor, The Cannigma
Have a burning cannabis question you need answered? Submit your questions to [email protected].