You never want to smoke concentrate that was freshly evapped. It needs more time to get trace molecules out always. Regardless of safety of solvent it needs to get them out. Alcohol needs to get out, butane needs to get out, everything basically! Triglycerides found in fats and oils are by definition esters of glycerol with long-chain carboxylic acids; the hydrolysis (saponification) or transesterification of these triglycerides produces stoichiometric quantities of glycerol.
When glycerol (also called glycerin) is heated to 280 °C(wow coincidentally bout the temp of a BIC lighter), it decomposes into acrolein. Acrolein is toxic and is a strong irritant for the skin, eyes, and nasal passages. The WHO suggests a "tolerable oral acrolein intake" of 7.5 μg/day per kilogram of body weight. the US Occupational Safety and Health Administration has set a permissible exposure limit at 0.1 ppm Not that we are winterizing cause anyone said fats were bad but congestive harsh and not psychoactive. Studies have also shown that charcoal is not selective (obviously, we remove grow odors with them) and a single pass can remove up to 50% of your cannabinoids along with other crap. winterizing removes the fats,waxes and other lipophillic (fat loving)compounds.
What makes them lipophillic or hydrophillic is based on polarity. butane is nonpolar (lipophillic) ethanol and iso are relatively polar, meaning they won't allow lipophillic substances. so if you heat the polar ethanol or iso it will absorb the extract left from a butane wash. After freezing it the solubility of the waxes and fats decreases. These lipophillic non polar waxes precipitate as a solid out of the solution. The waxes and fats removed make up the harshness and congestive properties smoked hash oil can sometimes bring. This process does not remove terpenes and will drastically increase the quality of a butane(non polar) extract. if you start with an isoor etoh wash its not as necessary and shatter can easily be produced using a single polar wash.. iso in the middle of butane and ethanol polarity wise giving the best extract only using asingle wash. but for compounds such as thca and precursory cannabinoids to move about the plant (as well as all compounds within the plant) they must be relatively polar. Because of this iso or etohcan extract a dirty product if left in solvent too long. which is why a long soak in butane that's allowed to pull every last cannabinoid and wax/fat. And then winterized to remove the wax/fats will give a better yield of quality product than iso or etoh. For a compound to have drug likeness it must be polar to aslight degree(allowing crossing of the blood brain barrier and to be soluble in the blood).. this slight polarity helps keep them in the ethanol as all cannabinoids have a hydroxyl group when the also lipophillic fats get pulled, the fats and waxes are also larger heavier compounds which hinders solubility. winterizing is how commercial perfume/essential oils are made, and if done properly will not harm the flavor,though I should mention the waxes and fats pulled often are somewhat fragrant.. It should be noted thc itself is an aromatic terpene, anything affecting flavor effects potency to an extent. Ido all my extracts in the dark and under 70 degrees even in the purge. 75 degrees or so is when lighter terpenes began to volatize into the air (Ialso dry/cure at 70or under for this reason) vapor pressures aren't linear too. polarity is relative, butane does not have a polar hydroxyl group -oh while iso and etoh do .
This is responsible for iso's high boiling point, even though its molecular weight is very similar to butane. and why water boils at amuch higher temp, being muchlighter than butane or iso. Hydrogen bonding is the strongest intra molecular force. Their is no defining line between polar and non polar. To find out,the biggest clue is molecular structure. ch bonds are non polar making hexane with more carbon a better non polar solvent. These hydrocarbon solvents lack the polar hydroxyl group that water iso and ever clear have.. but for them to hold cannabinoids in suspension and dissolve them they must also have anon polar side,which is why you can't winterize in water. likewise You can't winterize in a completely non polar solvent either. Look at a ph index polar water is 9iso somewhere around 4 etoh 6and butane 0 or .1..
This is because of the waxes increasing solubility in the non polar solvents.