Until recently, it was very difficult to find professional quality extractions without investing several thousand euros in a complex closed circuit system.
Herborizer offers one of the most interesting alternatives with this Passive Mini Closed Loop system. Closed circuit systems permit us to obtain better quality oils thanks to the purification of the gas (which we will discuss next) but also permits the almost infinite reuse of this refined gas.
Finally BHO lovers can try professional quality extractions thanks to this Mini Closed Loop by Herborizer. Compact in size, the tube measures 15cm in length by 4cm wide and the containers of the system measure 10cm x 10cm, being very easy to transport and particularly resistant thanks to its integral fabrication of 304 stainless steel. With a capacity of 45 grams of flower and approximately 400-500ml of butane gas, with this system it will be possible to recover between 4 and 7 grams of BHO in each session.
Above all, never forget that this type of extraction is potentially dangerous if the proper security measures are not respected. Although this is a closed circuit, it is always vital to carry out the extraction outdoors, in a well ventilated place.
How the BHO extractor works
This is one of our first attempts with this system. Our technique will definitely evolve and improve with time and experience, although these first sessions have convinced us completely and we won’t wait long before we extract again!
The principle of this type of extraction uses the temperature differences between the two vessels to displace the butane gas. In effect, butane will be attracted by the cold and repelled by the heat. It will be necessary to play with the temperatures to carry out the process and then recover the gas for later use in other extractions. We have to remember that this extraction system does not exempt us from having to properly vacuum purge before we can consume our BHO.
One last piece of advice before starting the description of the process: we must pay attention to the valves to ensure the gas remains concentrated in the system!
It is important to have all the necessary material to hand in order to carry out the extraction in the best possible conditions.
Material necessary for BHO extraction:
- Vacuum pump
- 2 saucepans or containers
- Dry ice or traditional ice
- Hot water
- Parchment paper for recovery
Filling the gas container
First of all we need to fill the tank from the gas canisters. A 300ml can of refined butane gas will suffice, although there is capacity for about 100ml more butane.
We connect the vacuum pump to the tank to create a vacuum inside it. Once done, we close the valve and disconnect the pump. Then press the butane bottle into the container inlet using an adapter if necessary, and immediately open the tank valve to let the gas enter it. Once the bottle is empty, we close the valve. We will have to repeat the operation if necessary.
At this point it is particularly important that the container is very cold, so don’t hesitate to leave the container in the freezer a day earlier to facilitate the entry of the gas.
If this is the first time we’re using this butane it’s advisable to perform a run without flowers, in order to remove the impurities contained in the gas. The gas bottle contains a greasy residue referred to in the world of extractions as “Mystery Oil”, an oil that serves as a lubricant used during the filling of the bottles to facilitate the entry of gas. It is in our interest to perform an extraction without vegetable material and then clean the recovery tank to remove this mystery oil: your gas will now be free of impurities, and ready to perform the finest quality BHO extractions.
Extraction with the Mini Closed Loop by Herborizer
At first, we will fill the tube with the flowers, which should be pre-frozen. The 150 micron filter is placed on the bottom of the tube, against the recovery container. The tube must be attached to the recovery container with the pipe clamps (the two containers are identical, so they can be used to store the gas or recover the resin interchangeably).
Close all tube clamps firmly with the help of a bolt to lever. It is crucial not to have any leaks in the extraction circuit. The same goes for the PTFE tube, it will be necessary to use a spanner to close it fully.
Once the recovery container with the tube full of flowers is connected to the gas container, the pump can be connected to pull vacuum within the extraction circuit.
Caution! In this phase it is necessary to keep the valve of the gas container closed. Open the other two valves, one is above on in the tube and the other is in the recovery container. The pump is connected to this last valve, on the recovery tank. Once the vacuum is complete, the two valves can be closed and the pump disconnected.
The Mini Closed Loop is now ready for extraction!
Before performing the extraction, we must verify that the valve on the recovery container is closed, and we must open the valve located in the tube with the herbs and the valve of the gas container. To speed up the process, you can turn the gas container over, place it higher up and cool the recuperator by putting ice in one of the saucepans.
You will see the pressure rise gradually on the pressure gauge. Check the gas container, if you do not hear liquid it’s because most of the gas is on the other side. The time to carry out this process may vary depending on the temperatures.
Recovery of butane gas
The extraction is done. Now we close the valves on the gas container and the tube. Once this is done we can disconnect the PTFE tube located above the grass tube and connect it to the intake of the resin collector, as you will see in the photo below.
The gas will now return to the tank thanks to the temperature difference between both tanks; To facilitate the recovery, the gas container must be cooled as much as possible, for which recommend using dry ice. On the other hand, you can fill a pan with hot water for the resin collector to increase the temperature difference.
As with the extraction, the time to finish this process can vary depending on the temperatures. Be careful not to heat the resin collection tank too much to avoid losing terpenes.
Collecting the resin the resin and conclusions
Once the pressure in the pressure gauge has dropped and we can clearly hear liquid in the gas tank, we can close the valves on the tank and recovery tank and remove the PTFE tube located in the resin collection tank.
Finally the valves located in the tube and in the collection tank can be opened. Be aware that there may still be gas inside, so the valves should be opened with great care.
Once the tube and clamps have been removed, we will be able to see the oil inside the collector. Depending on the temperatures applied, its appearance will be more or less liquid; in any case, we will need to empty the tank quickly and put the oil on a non stick material like Oil Slick sheet or Raw parchment to be able to continue purging with the vacuum pump.
Once the extraction is done, you can set aside the gas container and start to clean the system. Using a little isopropyl alcohol you can easily clean the remains of the oil from the collection tank. Next we remove the weed from the tube; thanks to its mirror-polished interior, the tube is very easy to clean and you’ll be able to see that almost no residue of resin sticks to the walls.
All that remains is the purging. After 24 or 48 hours of vacuum purging we can finally consume the results of our hard work.
In addition to getting a cleaner oil, we will also achieve a higher yield than with traditional extraction via open circuit or open blasting. For these tests we used between 25 and 30 grams of buds and small leaves to recover between 4 and 5 grams of BHO in each batch. The results will be even better if we use only the resinous buds.
We have made a video, to see in detail, how is the assembly of the equipment, the cleaning of the “mysterious oil” and the whole process of extraction and purging. It’s long, true, but we tell everything, or almost everything, about how the team works. We hope you like it:
We wish you all excellent extractions, and above all, plenty of caution when carrying out the process!