I never realized the oil could be that thick at high temperatures as to prevent the butane from being purged. Shows my lack of experience. I've always winterised my BHO, which seems to be a fairly uncommon practice amongst erlers, but the ethanol bath allows for the butane to be purged very easily with heat. Never realized that winterising was aiding the purge that much though.It depends on the amount of oil and the container size. It also depends on the strain. Some produce more viscious oil.
If its 4 cases of butane and 250 grams of oil in a 8x8 pyrex dish....its never gonna boil off at 100 degrees. The oil is too thick for the butane to get out without vigorous stirring or a vac