The distillation of terpenes is a steam distillation process. Water is turned to vapor and is diffused through the plant material. The water vapor (steam) sweeps out the flask and carries terpenes along with it to the condenser. As the terpenes and water condense back into a liquid the terpenes will naturally float to the top and can be poured off or you can use a pipette to remove or transfer them.
The key to this is to use a vacuum pump to reduce your pressure and lower temperatures. Reducing temperatures is key to preserving the terpene profile. The terpenes will readily alter its structure and turn into other terpenes or break down and degrade. Do not let temperatures rise above 50°C.
- Begin by grinding up your plant material. Grinding is not required but will greatly increase your yields.
- Add small piece of flower or loose piece of cotton to plug the lower joint on the bio-flask.
- Add your ground up flower to the bio-flask.
- Put boiling flask into heating mantle or reaction block/hotplate combo (you may need a lab jack or something similar to get the boiling flask and mantle high enough).
- Connect bio-flask to boiling flask by applying three small vertical strips to the top 2/3 of the joint (leave bottom 1/3 with no vacuum grease) apply force and spin until sealed. Repeat for all ground glass joints.
- Secure boil flask and bio-flask with stand and clamps.
- Add distilled water to boiling flask and fill half way.
- Seal neck joint with stopper or thermometer adapter (if using heating mantle).
- Connect vacuum adapter to receiving flask.
- Connect vacuum adapter & receiving flask onto condenser.
- Connect all three to still head.
- Connect all four items to bio-flask (make sure to use stands and clamps to secure position of set).
- Make sure all connections are sealed, securely in place, and not stressed or awkwardly positioned.
- Connect condenser to chiller or ice water circulator (in at the bottom and out on top).
- Connect vacuum pump to vacuum take off adapter.
- Turn on vacuum pump and start heating water to 50°C.
- You should see steam form in the bio-flask and then liquid in the condenser.
- Once distillation has begun you need to maintain it by adjusting vacuum and heating periodically.
- If ambient temps are too cold the plant material will become saturated in the bio-flask. If this happens use a heat gun or heating source to prevent condensation build up.
- Once the condensate is no longer milky or cloudy the distillation is complete. This generally takes less than one hour.
- After distillation has completed store in long tall container overnight and allow terpenes to float to the top.
- Decant or pipette off the terpenes to a clean container that is rated for use with terpenes (see chemical compatibility charts).
- Store under inert gas and low temperatures.
Adding Terpenes to Concentrate
- Place container with concentrate onto hotplate stirrer.
- Add stir bar to concentrate.
- Turn on stirring to 250rpm.
- Turn on heating to 40-50°C.
- Allow mixing for 5-20 mins.
Extracting your terpenes and re-introducing them preserves native terpene levels. Most solvent based extraction loses a great deal of the total volume of terpenes when the solvent is distilled away but with this method you can achieve 10-20% terpenes.
5% terpenes is plenty enough and 10% can be overpowering. The level of terpenes is a matter of preference but if you add too much it makes it gooey and the consistency is much more difficult to handle or work with.