Butane is a very popular solvent used in cannabis extraction to make beautiful concentrates called Butane Honey Oil (BHO). Crafting clean and safe BHO requires some knowledge and skill but it’s not overly difficult and can be learned easily. Performing butane extraction at home is very dangerous so I don’t recommend it and urge everyone to find a safer method for home extraction. Having said that, if you somehow end up with BHO that resembles a cloudy, wax laden, contaminate filled, proverbial “poop soup” you can use the “winterization” process, with food grade ethanol (95% or higher), to clean and polish your concentrate. Winterizing will eliminate the majority of remaining butane and remove undesirables like fats, lipids, and waxes, giving you a beautified concentrate that’s vastly more appealing and safe than the origin material. In this post I will share my experience of using winterization to clean up an unattractive glob of BHO like this.
This is what dirty BHO looks like and only God knows what’s in it. This is what will be cleaned up in this demonstration.
Step 1: Ethanol Bath
Introducing a butane extraction into 95% ethanol is a very efficient way to purge excess butane and separate out undesirables. The butane extract must be completely purged of ALL butane before moving past this stage. Most references floating around recommend combining ethanol and concentrate in a 10:1 ratio. To my experience thus far I’ve found 10:1 to be insufficient. In this demonstration I used about 15:1, and would encourage using up to 20:1 if the BHO is dirty enough. Using too little ethanol may result in leaving a good deal of desirable components behind with the undesirables once we filter out the waste. To begin, carefully heat the ethanol to 110°F-120°F in a very well ventilated area, on a hot plate, away from any open flame or ignition source, and defiantly not over a gas stove burner. Remember, ethanol is very flammable and needs to be handled with the highest regard for safety.
A fresh, loose butane extraction will combine with ethanol readily, however, if the concentrate has already set up in a stable form it’ll take time to dissolve into a solution. Stirring the heated mixture allows a fresh butane extraction to release the purging gas through active bubbling, while dissolving a stable concentrate may not experience any bubbles. The solution must be stirred until the concentrate is completely dissolved and the bubbling has subsided.
DEMONSTRATION: I started with 42.5g of poop soup, divided it in half, and put each 21g half in a glass jar with about 300ml of ethanol (nearly 15:1). The undesirables began to coagulate and form together in cloudy globs very quickly.
**ALL BUTANE MUST BE 100% PURGED BEFORE MOVING ON**
Step 2: Freeze Solution
Subjecting the ethanol bath to freezing temperatures encourages the undesirables to coagulate, solidify and become fully suspended in the solution. This step can be accomplished in the freezer for 48-hours or with dry ice for at least 3-hours. For optimal results it’s important not to disturb the solution during the cooling phase.
DEMONSTRATION: In each of those jars is 21g of BHO concentrate being winterized. The left photo was shortly after it was put in the freezer and the photo on the right was after 48-hours of chilling.
Step 3: Filter Out Coagulated Undesirables
Anything from unbleached coffee filters to various grades of filter papers and Buchner funnels are acceptable for this task. The undesirables are quite easy to filter so faster flow filters, like coffee filters, are probably sufficient but I still use a slow flow paper filter to catch as much as possible.
DEMONSTRATION: This is the combined filtered results of both jars after chilling in the freezer for 48-hours. The filtered undesirables are plentiful and obviously very different than the resulting filtered alcohol solution seen in the beaker on the left.
Step 4 (optional): Reprocess Collected Undesirables by Repeating Steps 1-3
If the undesirable byproduct of the first filtering seems heavy, once again combine the undesirable contents to clean ethanol, and repeat steps 1-3.
DEMONSTRATION: The 21g wet weight of undesirables seemed excessive so 400ml of ethanol was used to break it down again then placed in the freezer for another 48-hours.
DEMONSTRATION: The second filtering resulted in undesirables of a much more solid form, 2.27g of a hard wax, and a beautiful golden wash. This wash was significantly lighter in color than the original filtered wash. Both washes had the same components, but due to the lower component density this one was much lighter.
Step 5: Purge Ethanol:
The wash is nothing more than a combination of cannabis oil and ethanol, but to isolate the coveted cannabis oil for use as a concentrate the ethanol must be removed. How well this step is performed will have a large impact on the quality of the final product. My goals during this step are to use minimal heat, finish expediently, and recover as much alcohol as possible. For this task there’s only one affordable, easy to use, at home appliance for the job, the Source Turbo by ExtractCraft (www.extractcraft.com). If using the Source, for safety of operation, you must make absolutely sure there is no butane remaining in the wash. No butane can be used in the unit. You can run 300ml per batch, clean about 21 grams of dirty extract at a time, use only around 100°F to keep the terpenes strong, and reclaim 95% of the ethanol safely in the home in a little more than two-hours.
DEMONSTRATION: The results from the initial filtering were clean and looked great. A total of 32g of quality concentrate was recovered from this batch. An additional 4.5g was recovered from the second wash of the re-filtered undesirables. Total recovery from the original 42.5g was 86%.
Step 6: Post-Process as Desired
I threw the delicious oil in the vac oven and made some happy days! You can too!
1. Poop soup is gross but can be cleaned and polished with a little bit of effort and know-how.
2. The Source Turbo (www.extractcraft.com) is very useful and performs perfectly in this operation.
3. The end result of the darker initial wash and the substantially lighter wash from reconstituting the undesirables came out exactly the same, so wash color indicates concentration as much as quality.
4. There’s too much nonsense and too many fools in the world to be without clean medicine to stay lifted, so take the time to make yourself some quality meds you can enjoy.