once the terpenes evaporate, there is no way to put it back into your oil. once you can smell them in the air, they are gone. if your intent is to preserve more of the volatile terpenes, then purging with little to no heat is your only choice. the best way to do this would be to use ethanol or ISO as a co-solvent to allow the butane to escape easier, and then vaccing for an extended period of time without heat, once most of the butane has evaporated and you are left with the ethanol/extracted goodies. This may take a couple days to fully evaporate, but is your best bet. also whoever mentioned water curing, terpenes are soluable in water, this will only make your end product come out as tasteless and bland. now if you are running ABV or some really nasty nuggets, this might be worthwhile, otherwise it is more or less retroactive to your intent for the most flavorful and pungent concentrate you can produce.