There is no way to remove all the butane from butane based oils.
Even with bubble hash there is a danger of concentration of pesticides.
Double the risk if you're buying your oil off the street (CO has some standards on pesticide in place).
I strongly recommend doing extensive research before choosing to make oils a steady thing. I personally have gone through a ton of research and have avoided DABbbling with concentrates ever since.
Actually, bubble hash in the scientific literature that exists so far has been found to be a technique that if anything removes, rather than concentrating pesticides!
https://www.jstage.jst.go.jp/article/jts/40/6/40_797/_pdf check out this study from the Journal of Toxicological Sciences which proposes that the reason for bubble hash being cleaner than the other Californian concentrates that they studied is likely to be the water processing used in bubble hash. Very large quantities of water are run through these extracts while they are processed. Pesticides that are applied to plants are generally water soluble (allowing the water to be mixed with the pesticide for application and also allowing the pesticide to be washed off with water). Your pesticides are largely, if not completely going to end up in the water, rather than in the hash.
To drill right down into the study's findings. The following pesticide chemicals were specifically identified:
Paclobutrazol - the most water soluble of the bunch, will rinse off of a product with water.
Myclobutanil - Less water soluble, but will still wash away with water. Myclobutanil is known to leave the site of application with ambient water runoff in a grow situation, let alone with the much greater agitation of harvested material in much larger amounts of water used for bubble.
Bifethrin - this one is the least water soluble of those detected, but can be dispersed with water.
Of course, resin is not water soluble which is why bubble tek works
If you suspect material is pesticide contaminated - short of just throwing it away - on the best available current information your safest option is actually to make it into bubble. Remember as well that pesticide contamination is a problem with consuming flowers and also remember that we tend to use more flowers to get the same effect as a dab for obvious reasons and that extra exposure from additional usage could balance out any concentration effect on the pesticides in non water-washed concentrates.
Bottom Line IMO: Pesticides are still a major issue across the board in many jurisdictions. More than anything, you need to find growers that refuse to use pesticides and extractors that require pesticide tests on their raw material if you want peace of mind - whatever you want to consume. Flowers or concentrates, we all need to avoid pesticides!
BTW properly stored high end hashes get better with age too, not worse (curing works better with bubble because when done right, you can much more easily prevent mold in long term storage of hash than flowers!), I have some bubble hash that is approaching 4 years of age and I am sure you guys would love to have this in your vape! Of course, if the hash is stored in the wrong conditions - that is another story!
Also very high end (usually fully melt) hashes that cost substantial amounts of money are generally such because the yields are negligible compared to processing the same weight of flowers with a solvent.
I am a processor (but not seller - I make my own personal medicine) of hash of this quality and can safely say that with some varieties (see my avatar for an example of a low-yielde), 1-1.5g yield from 1 oz of flowers is not an unreasonably low yield (5%-10% of total weight is normal return for high quality bubble). Now consider that you'd generally expect to get between 4-10g with a solvent extraction performed on a oz. Now we can understand why we tend to see a major cost increase in the price for such concentrates
. Also remember that the labor involved in hashmaking is considerably greater (ime easily 5-10 times more time spent doing hands-on processing for bubble) than that involved with solvent processing.
The upshot of these concentrates is that the additional terpene content found in high quality hashes (total terpene concentrations of >20% in some cases!) is only going to be matched by the most bleeding edge of solvent based teks (Extractioneering is a good example of someone who makes concentrates with solvents that can easily match the terpene concentrations found in high quality hash - this is quite a feat!). Your average BHO is only getting ~5% of total terpenes in the errl (flowers, much less again!). There is no comparison.
I do not consume solvent based concentrates because solventless methods produce better medicine, without a properly fitted lab being required to deal with much more dangerous solvents than any of us should be keeping at home. Interestingly, in the study above, there was a greater transfer efficiency of THC (more THC in your system from consumption) for the hashes, vs the other concentrates in the study I quoted above.
Bubble hashes should always be tested for bacteria/fungus etc as a main concern of course. These are considerations that also apply for most food/produce (remember too back to my earlier point on pesticides that we rinse fresh fruit/plant produce with less water for a shorter amount of time than in bubble processing, in no small part to ensure that we do not consume pesticides!).
Hope this clears up some of the points here and
@Cuthbert J Twillie - what you are saying about possible concentration of pesticides is definitely an issue with solvent extractions which may be where you had first heard this idea.
I think I saw one that was $175 a gram!
