Butane hash oil (BHO) extraction

Do not perform this procedure indoors.

Due to the explosive nature of the solvents involved, attempting this procedure in underventilated areas (e.g. such as a small apartment room or basement) can result in serious injury, death or the destruction of property.

Disclaimer: This guide is provided for informational and educational purposes only. We do not encourage you to break the law and cannot claim any responsibility for your actions.

This preparation is for the extraction of hash oil from cannabis using liquid butane (commonly referred to as B.H.O). The aim of this extraction guide is to provide a simple and straight-forward procedure for the home user to produce a personal amount of high-quality hash oil. This extraction tek does, however, require the use of more advanced equipment such as a vacuum pump.

Flammability Risks

Butane is a flammable gas that has no odor and accumulates indoors and in unventilated areas. The acculumation of enough butane gas in an area presents a significant risk of explosions, which can be fatal, due to the flammable nature of butane. Upmost care and caution must be used when working in an environment that contains butane gas. Preforming this extraction indoors significantly increases the risk of fires, explosions, and physical harm - it is not advised from a harm reduction point of view. Outside of a fully functioning fume hood, the production of BHO indoors carries with it a great inherent risk for explosions and bodily harm.

A "well-ventilated area" is commonly used to describe the area that is ideal for butane extraction. A "well-ventilated area" is not a room with the window open, it is not a kitchen stove top fan turned on, it is not a garage with the door open to let some air in - these areas do have ventilation, but the movement of air is unpredictable and may lead to explosions if butane does build up in the room. To be well ventilated, an area must have a constant and steady supply of fresh air flowing through the area. This is achievable indoors in a fume hood (commonly seen in chemistry labs) and is de facto achievable outdoors. Preforming a B.H.O. extract in a "well-ventilated area" does not eliminate the flammability and explosion hazard associated with the process, it only lowers this risk.

While butane is a flammable gas, in order for an explosive event to occur there needs to be an ignition source or spark. This spark can come from common sense items such as a lighter or pilot light on a stove, but sparks can also occur in less obvious ways. Electric sparks can be created simply by wearing clothes - the common "shock" one experiences after shuffling around with socks on and touching a metal object is sufficient to cause an explosive event if the concentration of butane is at 1.86% of atmospheric levels.

Both a spark and a sufficient quantity of butane are necessary for an explosion to occur - if either one of these is lacking, by pure chance, an explosive event will not occur. Just because there have been experiences of producing B.H.O. indoors without explosive events does not mean it is a safe practice; this element of chance can render a dangerous operation intert.

Equipment

• Ground cannabis - You can make batches with as little material as you like although it is recommended that at least a half ounce be used for technical and economic reasons. The yield is highly dependent on the strain, but one can typically expect the end product to come out to around 15% by weight.
• Filtered butane - Butane is available in a variety of grades dependent on how many times it has been filtered. Generally speaking, the more times it has been filtered, the better, but at a certain point filtering something more times isn't going to make a qualitative difference so be mindful of diminishing returns! There's also n-butane and other blended gas solvents of various kinds. These are typically much more expensive but are thought to increase the quality of the end product. All gaseous butane solvents are highly flammable.
• Extraction tube - Thick glass is highly recommended although plastic and other types will work reasonably well. Glass is prefered due to the reduced probability of chemical leeching and byproducts associated with plastic equipment.
• Vacuum chamber and pump - A single stage pump is fine. Be wary of shorter chambers as the oil might bubble high enough to touch the lid.
• Coffee filter and rubber band or hose clamp
• Pyrex or glass baking dish - This should have a large surface area to increase the evaporation rate of the solvent.
• Protective gloves and mask - This is needed to protect against the frozen tube and butane vapors - proper safety wear is imperative for a B.H.O. extraction.
• Lower temp electric heat source - Avoid any open flame heat sources and heat sources that can cause flammable sparks as butane is highly flammable and explosive! An induction hot plate is a viable heat source option.
• Fire extinguisher - This can make the difference between life and death if a fire or explosion occurs.
• Parchment paper or slick mat
• Laser thermometer - This greatly aids in temperature control.

Procedure

1. Break up (not grind) the cannabis into small and loose pieces. This increases the surface area for the solvent and maximizes the amount of medication extracted.
2. Pack your extraction tube in a firm manner. Be careful not to pack the tube over as the butane must be allowed to flow through the material freely by the force of gravity.
3. Cover the open end with two coffee filters and secure with rubber band or clamp.
4. Freeze your filled tube in your freezer in an air-tight container (to prevent condensation) for a minimum of 2 hours.
5. Once frozen, put on the protective gloves and mask and remove the tube from the freezer and place the pyrex dish in a WELL ventilated space(do NOT skip this part, see warning above).
6. Begin pouring the butane into the tube from the small vent opening on one end. The butane should flow through the material to the bottom end and be collected into the pyrex dish. The tube will become very cold or frozen and near impossible to hold without heat-resistant gloves.
7. Continue to pour the butane into the tube until it runs clear.
8. At this point allow most of your solvent to evaporate from the dish in the well-ventilated space. Agitate occasionally at a safe distance.
9. Once most of the solvent has evaporated, pour the oil onto a parchment or slick mat and place it into the vacuum.
10. Turn on the vacuum and allow to reach full vacuum capacity which is typically around 29 in/Hg at sea level. The oil will begin to bubble and muffin up as the trapped butane escapes the chamber.
11. Wait several hours for the muffin tops to fall and the bubbles to stop forming.
12. Once the activity has stopped place the chamber on the heat source and gently raise the temperature to 100-120 degrees. Be very careful not to add too much heat as this will burn off terpenes and darken the end product. Wait for any remaining bubbles to stop and remove it from the vacuum.
13. Carefully try to flip the oil and melt it into the thinnest layer possible. Again take care not to add too much heat or fold air into the product as this will add moisture and trap in gasses which will affect the translucence and smoothness of the end product.
14. Place the thin layer of oil back into the chamber at full vacuum. Leave on over night.
15. Repeat the final five steps as many times as necessary to fully purge the oil of impurities.

• File:Ground Flower
• File:Packed Tube
• File:Frozen Tube
• File:Butane Evap
• File:Vacuum Chamber
• File:Purge
• File:Final product

Notes

• Oil making is highly dependent on the strain. A wide variety of different looking products can result from this tek and may range from 'shatter' (the highest grade) to 'crumble' to 'wax' or anywhere in between. High THC strains often tend to "sugar up" and is prized by many for the smoothness of its vaporized taste.
• If you are looking to make a more crumble type product it is recommended to fold the oil into a tight ball and purge it repetitively over and over -- this will cause the oil to wax up, allowing bigger butane bubbles to form. The final purge of this oil will be with a blast of heat to let the large butane bubbles to pull out of the oil. 'Warning': If this step is done improperly, some butane may become trapped in the almost solidified oil.
• Be careful not to rip the coffee filter, especially when it is wet!

References

_{The information contained in this article was acquired and accumulated from the sources below and should in no way indicate that the author or authors have any practice in illicit activities.} Salem (talk) 13:59, 12 January 2015 (UTC)

• https://skunkpharmresearch.com/bho-extraction/
• https://skunkpharmresearch.com/vacuum-purging-and-processing-tips/