I’ve tried some delicious cannabis kombucha brands here in California, where adult use of cannabis is legal. Commercial brands mix a THC-infused emulsion into kombucha that’s already brewed.
I hadn’t heard of anyone including cannabis in the fermentation. I wasn’t sure what would happen. Would the SCOBY be okay, or would it get paranoid and climb out of the jar? Would it ferment? I used vegetable glycerin to emulsify the THC into the simple syrup. I read that glycerine is bacteriostatic (a compound that freezes the metabolic action of bacteria, without killing them). Would this throw off the fermentation in any way? Only one way to find out!
UPDATE: After experimentation, I concluded that it’s preferable to simply infuse the cannabis syrup into a secondary kombucha fermentation. See notes at bottom of this post for the original experiment.
I found that the secondary fermentation with cannabis syrup is slower than with other adjuncts I commonly use (fresh squeezed fruit juice, dried or fresh herbs, ginger), so I adjusted the length of time to reflect that.
The syrup I made used some old trim for which I did not know the THC content, so I had to estimate the THC content.
STEP 1: Make Cannabis Syrup
You will first need to create cannabis-infused simple syrup.
STEP 2: Make Kombucha (primary fermentation)
Follow our classic recipe for kombucha.
STEP 3: Make Secondary Flavored Cannabis Kombucha
The recipe below creates a finished kombucha with about 10mg THC per 8 ounce serving.
- 24 oz. (750 ml) mature kombucha
- 1 Tbsp. + 2 tsp. (25 ml) cannabis syrup
- 15g fresh ginger, cut into matchsticks
- swing-top bottle
- With a funnel, add cannabis syrup to a clean glass bottle (either a swing top or one with a cap which can tighten.)
- Add ginger pieces to bottle.
- Top with plain kombucha. Leave no more than ½" of head space in the neck of the bottle. Close tightly.
- Ferment 4-14 days, burping occasionally (over the sink) to release gas buildup.
- When you like the flavor and carbonation, move bottle to refrigerator.
- Before serving, gently rock (DO NOT SHAKE) the bottle by inverting it a few times. This will allow any sediment to be better incorporated into the beverage when you pour it.
- Serve chilled to reduce the chance of the bottle overflowing with carbonation. Enjoy responsibly.
Kombucha (primary fermentation) with cannabis syrup
In order to test whether the fermentation affects THC content, I tried a scientific-ish experiment. I tasted a spoonful of cannabis syrup mixed in with regular kombucha, and then studied the effects. Then I tried an equivalent amount of syrup in the fermented-with-cannabis batch. The effects of the fermented batch were indeed more mellow. So it appears that the fermentation process reduces the THC content at least a little.
The effects of the cannabis when it’s been fermented in with the kombucha are noticeably more subtle than when consuming the syrup without fermentation. The finished kombucha has a really nice aroma (subtle terpenes), and is quite tasty. Many testers report that they couldn’t detect any flavor of cannabis. I’ll keep working on the recipe. Most would therefore argue that it’s not a good technique because it is loses potency during fermentation. That could well be true. I still enjoy drinking the kombucha and its light effects. I will continue the experimentation again using more and stronger syrup.
Always store scobys used in this recipe separately from other “non-cannabis” scobys. Best is to store them in their own jar (always at room temperature– never in the refrigerator!) in a little of the reserved liquid from the last batch you make. Keep a cloth lid on top of the jar to keep out flies and allow the scoby to continue to breathe. It doesn’t need much liquid to hang out– just enough to keep it submerged.
- Meet the Cannabis Kombucha Guru, herb.co. Accessed Mar. 20, 2018
- Cooking with Cannabis: Delicious Recipes for Edibles and Everyday Favorites. Wolf, Laurie.
- How to Calculate Edible Potency, keytocannabis.com. Accessed Mar. 12, 2018.
- How to calculate THC dosage in recipes for marijuana edibles, thecannabist.co. Accessed Mar. 12, 2018.
- Dosing Homemade Cannabis, Cooking with Cannabis, Part 4. Leafly.com